Approved by

Order of the Federal

Environmental, Industrial

and Nuclear Supervision Service

dated 2 March 2018 No. 94

FEDERAL RULES AND REGULATIONS

IN THE FIELD OF NUCLEAR ENERGY USE "REGULATIONS FOR DESIGN

AND SAFE OPERATION OF STEAM AND HOT WATER PIPELINES

FOR NUCLEAR FACILITIES"

(NP-045-18)

I. Purpose and scope

1. These Federal Rules and Regulations in the area of nuclear energy use "Rules for arrangement and safe operation of steam and hot water boilers for nuclear facilities" (NP-045-18) (hereinafter referred to as the Rules) are developed in accordance with Federal Law No. 170-FZ dated November, 21, 1995 "On nuclear energy use", Provisions for development and approval of federal regulations and rules in the area of nuclear energy use approved by Decree of the Government of the Russian Federation No. 1511 dated December 1, 1997 (Collected Acts of the Russian Federation, 1997, N 49, art. 5600; 2012, N 51, art. 7203).

2. These Rules establish the requirements for design, manufacturing, refurbishment (upgrade), installation, adjustment, repair, technical diagnostics and operation of steam and hot water pipelines specially designed for application in the area of nuclear energy use (hereinafter referred to as the pipelines) and referred to components of safety class 4 (according to classification established in compliance with federal rules and regulations  in the area of nuclear energy use).

3. These Rules are applicable to pipelines, as well as valves, pressure-reducing facilities, pressure-reducing desuperheating facilities (hereinafter referred to as PRDP), fast-response pressure-reducing desuperheating facilities and headers which constitute a part of pipelines for water steam with operating pressure <*> over 0.07 MPa or hot water with temperature over 115 °C, except for:

--------------------------------

<*> Here and below, excessive pressure is indicated.

1) category I pipelines with the outer diameter of less than 51 mm and category II, III and IV pipelines with the outer diameter of less than 76 mm;

2) drain, blowdown and exhaust pipelines, PRDP and other devices connected to the atmosphere;

3) pipelines of nuclear power plants of ships, aircrafts and spacecrafts;

4) pipelines made of non-metal materials;

5) pipelines and heating registers of buildings and structures, as well as hot water pipelines used for household needs;

6) pipelines built into equipment;

7) bypass pipelines within turbines, turbine binding pipelines up to the isolation valves, including turbine steam extraction pipelines.

4. All pipelines covered by these Rules are divided into four categories (Table No. 1 hereof).

Table 1

Pipeline categories and groups

If parameters of the medium belong to different categories, the pipeline shall belong to the category correspondent to the maximum value of medium parameter.

5. For the purpose of defining the pipeline category, the following parameters shall be considered as working parameters of the transported medium:

1) for steam pipelines from the steam generator, separative steam superheater - steam pressure and temperature based on their nominal output values (behind the steam superheater);

2) for steam pipelines from uncontrolled and controlled tubrine steam extractions (including intermediate reheating steam pipelines) - the maximum values of reduced steam pressure and temperature specified in the design and engineering documentation (hereinafter referred to as the DD);

3) for steam pipelines from pressure-reducing plants and PRDP - the maximum values of reduced steam pressure and temperature specified in the DD;

4) for feed water pipelines installed after increased pressure deaerators - nominal water pressure taking into account the hydrostatic head pressure and the saturation temperature in the deaerator;

5) for feed water pipelines installed after feed pumps and high pressure heaters (hereinafter referred to as HPH) - the maximum pressure created in the pressure pipeline by the feedwater electric pump in case of closed gate and maximum pressure at the suction line of the pump (in case of using turbine-driven feed pumps and electric pumps with a hydraulic coupling - 1,05 of the nominal pump pressure) and the maximum design water temperature behind the last HPH.

6. Pipeline category defined in accordance with the working medium parameters at the pipeline inlet (if it is not equipped by any devices changing these parameters) applies to the whole pipeline regardless of its length and shall be specified in the DD.

12. Assessment of compliance for pipelines shall be performed in accordance with the requirements of federal rules and regulations in the area of nuclear energy use establishing the rules of compliance assessment for the products subject to the requirements related to safety assurance in the area of nuclear energy use.

Engineering, design and process documentation for the equipment and the pipeline's parts and assembly units manufactured prior to entry of these Rules into effect or being manufactured as per the moment of entry of these Rules into effect shall not be subject to any amendment.

Terms and definitions used in these Rules are given in Appendix 1.

II. Pipeline structure

General requirements

8. Pipeline structures shall comply with the requirements of these Rules, and their strength and operability shall be substantiated for all design operation modes within the service life of the pipelines established by the general designer.

9. The DD for pipeline manufacturing and operation shall be developed by the designer of the nuclear energy use facility or by the organization performing corresponding works prior to the start of their performance in accordance with these Rules, as well as other regulatory legal acts and documents of the operating organization (including standardization documents regulating the requirements for design, arrangement, manufacturing, refurbishment (upgrade), adjustment, installation, repair, technical diagnostics and operation of pipelines) (hereinafter referred to as the RD).

10. Any changes in the design of the pipeline and its components necessary in the course of installation, operation, repair or refurbishment (upgrade) shall be approved by the general design organization.

11. The calculations for the strength of the pipelines with due regard for all load factors (pressure, weight, thermal expansion) shall be performed in accordance with the strength calculation standards.

Based on the results of these calculations, the design organization determines a design service life for pipelines of all categories, and a design lifetime for category I and II pipelines (provided that the number of their cold condition starts during the design service life does not exceed 3,000). For all other types of pipelines, a design number of cold condition starts shall be established.

The determined design characteristics shall be recorded in the pipeline certificates.

12. Pipelines shall be designed in such a way that all types of testing required by these Rules could be performed.

13. The connections between pipeline parts and components shall be performed by means of welding.

The use of flange connections is acceptable only for connections between pipelines and valves or equipment parts equipped with flanges.

Threaded joints are acceptable for attaching cast iron valves to pipelines of safety class 4 with nominal passage of 100 mm and less.

14. Tee joints made of pipes with longitudinal joints may be used for pipelines of safety class 3 and 4, and the quality of all welded joints shall be checked by means of radiographic or ultrasonic control (hereinafter referred to as USC).

15. Corrosion protection measures shall be stipulated for pipelines and their bearing metal structures.

16. All components of heat-exchanging equipment with the external surface temperature exceeding 45 °С, located in attended rooms shall be subjected to heat insulation; the temperature of external surface of heat insulation shall not exceed 45 °С, and 60 °С in the rooms with limited access.

On category I pipelines heat insulation shall be removable in the places of location of welded joints and the points where metal creep is measured.

17. No components can be welded to welded joints and elbows of category I and II pipelines.

Curved components

18. Curved components' structure shall comply with the requirements of the DD.

19. Pressed and welded elbows may be used with one or two longitudinal weld joints of diametrical arrangement provided that radiographic control or USC is performed along the entire length of weld seams.

20. Well sector bends can be used on category III and IV pipelines. The sector angle shall not exceed 30°. The distance between the adjacent weld joints on the inner surface of the elbow shall ensure control of these joints from both sides on the outer surface. Spiral seam pipes shall not be accepted for manufacturing of sector elbows.

21. The elbow wall thickness at each of its parts shall not be less than the values established by the strength calculations and the technical specifications (hereinafter referred to as the TS) for its manufacture, and shall be recorded in the pipeline certificate.

The wall thickness shall be measured in accordance with the procedure specified in the product DD.

22. It is not permitted to use elbows curved due to creases (corrugation) inside the elbow.

23. The maximum out-of-roundness of the cross section of the elbow shall be determined according to the following formula:

,

where D_amax, D_amin are the maximum and minimum outer diameters in the measured elbow section.

The out-of-roundness of the cross section of the elbow shall not exceed the values specified in the DD.

Weld joints and their location

24. The location of all welded joints on pipelines (including joints of welded-on components) shall ensure the possibility of its control with the use of methods specified in these Rules and the DD.

25. The connection of pipes and shaped parts shall be performed by means of butt welding with complete penetration.

Angle weld joints are permitted for welding of Angle and T-shaped full-penetration weld joints are permitted for welding of nozzles and flat flanges to the pipelines. Angle weld joints shall be performed with complete penetration.

It is permitted to use corner welds with a structural gap (constructive lack of penetration) to weld pipes and nozzles with the inner diameter not exceeding 100 mm as well as flat flanges with a rated pressure of 2.5 MPa and less and a temperature of 350 °C or less. The quality control of such joints shall be conducted in accordance with the requirements of the DD.

Overlapping joints shall be permitted only in cases stipulated by the DD.

26. In case of weld joints of components with different wall thickness, a smooth transition from the larger cross-section to the smaller section shall be arranged by means of one-side or two-side mechanical processing of the end of the component with a thicker wall.

Inclination angle of the transition surfaces shall not exceed 20°.

In case the difference in thickness of the connected components is not more than 30% of the thinner component thickness and does not exceed 5 mm it is permitted to use weld seams without prior thinning of the thicker component. Shape of seams shall ensure smooth transition from a thicker component to a thinner one.

In case a cast part is mated to parts made of pipes, rolled products or forged pieces it should be taken into account that the nominal design thickness of the cast part is 25-40% more than the similar design wall thickness of the component made of pipes, rolled products or forged pieces thus transition from the thick-walled component to the thin-walled one shall be arranged in such a way so that wall thickness at the end of the cast part would be at least equal to the design value.

27. In case of welding pipelines and other components with longitudinal and spiral weld joints, the latter shall be shifted with respect to each other. The shift shall be at least equal to three-fold pipe (component) wall thickness, but not less than 100 mm for pipes with the outer diameter of over 100 mm.

28. For the transverse butt-welds not subject to USC or local heat treatment, the distance between the seam exes of adjacent weld joints  on straight pipeline sections shall be at least equal to the three-fold pipe (component) wall thickness, but not less than 100 mm . The distance from the weld joint axis to the beginning of elbow curving shall be at least 100 mm.

29. For the transverse butt-welds subject to USC the length of a free straight pipe (component) section to each side of the joint axis (to the closest welded-on parts and components, start of a bend, axis of the adjacent transverse weld) shall be not less than the values specified in Table No. 2 of these Rules.

Table 2

30. For the transverse butt-welds subject to local heat treatment the length of a free straight pipe (component) section to each side of the joint axis (including to the closest welded-on parts and components, start of a bend, adjacent transverse weld) shall be not less than the value I, but not less than 100 m and shall be calculated according to the following formula:

,

where:

D_m is the average pipe (component) diameter;

D_m = D_a - S;

where D_a is the nominal outer diameter, mm;

S is the nominal wall thickness of the pipe (component), mm

31. In case of installation of sharply bent turns, stamped and stamp-welded elbows, cross-sectional weld joints may be located near the beginning of curving and sharply bent turns can be welded together without a straight section between them.

32. For angle weld joints of pipes and nozzles with pipeline components, the distance between the exterior component surface and the start of a pipe bend or a transverse butt-weld shall be equal to:

1) for pipes (nozzles) with outer diameter less than 100 mm – not below the pipe's outer diameter, but not less than 50 mm;

2) for pipes (nozzles) with outer diameter of 100 mm and more – not below the pipe's outer diameter, but not less than 100 mm.

33. The distance between the welded joints transverse axis to the edge of a support or a suspension shall be determined based on the possibility to carry out examination, control and heat treatment of this welded joint as stipulated by the DD.

Laying of pipelines

34. The DD for laying of pipelines shall be designed taking into account the requirements of these Rules, seismic resistance and vibration strength requirements as well as of effective sanitary regulations and standards.

Underground laying of category I pipelines in one channel with other process pipelines is prohibited.

35. In case of laying pipelines in semi-passable channels, the height of channels in the clear shall be at least 1.5 m, and the width of the passage between isolated pipelines - at least 0.6 m.

36. In case of laying pipelines in passable channels (spaces), the height of the channel (space) in the clear shall be at least 2 m, and the width of the passage between isolated pipelines - at least 0.7 m.

In the places where shutoff valves (equipment) are located, the tunnel width shall be sufficient for maintenance of the valves (equipment) installed. In case of laying several pipelines in one tunnel, their mutual arrangement shall ensure the possibility of repairing pipelines and replacing their components.

37. In case of above-ground open laying of pipelines, pipelines of all categories can be laid together with process pipelines of various applications save that such arrangmenet violates the requirements of the DD.

38. Underground pipeline maintenance chambers shall have at least two manholes with ladders or staples.

39. Passable channels shall have access hatches with a ladder or staples. The distance between hatches shall not exceed 300 m, and in case of laying pipelines of various categories together - 50 m. There shall also be access hatches at all dead points, route turns and valve locations.

40. Horizontal pipeline sections shall have an incline of at least 0.004; for heating networks pipelines an incline of at least 0.002 is acceptable. Pipeline routing shall exclude the possibility of water stagnation areas.

41. Valves shall be installed at locations where maintenance and repair is possible. If necessary, stationary ladders and maintenance platforms shall be installed.

42. Cast-iron valves installed on pipelines of safety class 4 shall be protected from bending stresses.

Compensation of thermal expansion

43. Each pipeline section between fixed supports shall provide for compensation of thermal elongation by means of self-compensation or installation of compensation devices. The precise locations for compensator installation shall be determined by the DD. It is not acceptable to use cast-iron expansion glands.

44. On steam pipes with the outer diameter of at least 150 mm and steam temperature of at least 300 °C, travel indicators shall be installed to control the steam pipelines expansion and monitor the operation of the supporting and hanger system. The indicator locations and calculated travel values shall be specified in the pipeline DD. Travel indicators shall be provided with free access.

If pipelines are located in unattended rooms, travel control and recording shall be performed remotely.

Supporting and hanger system

45. The pipeline bearing structures, its supports and hangers (except for springs) shall be designed to endure the vertical load of the weight of a pipeline filled with water and covered by heat insulation, and the forces occurring due to the thermal expansion of pipelines.

The steam pipeline supports and hangers can be designed without taking into consideration  the water weight in case of hydraulic testing, but with due regard to the steam weight. In this case, the DD shall stipulate the application of special devices for unloading springs, supports and hangers during hydraulic testing.

46. Fixed supports shall be designed to endure the forces transferred to them in the most unfavorable combinations of loads which can occur in case of normal pipeline operation, design accidents and the safe shutdown earthquakes at nuclear energy use facilities (hereinafter referred to as AEUF).

Drainages, air vents, heating up and discharge devices

47. It is necessary to install bleed nippers equipped with shutoff valves for pipeline drainage in the lower dots of each area switched off by the pipeline zone gate valves.

Air vents shall be installed in the upper dots of the pipelines for air withdrawal.

48. All steam pipelines sections which can be switched off by gate valves shall be equipped with nozzles with valves in the end points for heating up and blowdown, and if the pressure is over 2,2 MPa - with a nozzle and two sequentially located valves: a shut-off one and a regulating one. Steam pipelines with pressure of 20 MPa and more shall be equipped with nozzles with the sequentially located shut-off and regulating valves and an orifice plate. In case a pipeline section can be heated in both directions, the purging shall be possible from both section ends.

The drainage devices shall ensure their control during pipeline heating.

49. The lowest points of steam pipelines and the lowest points of their bends shall be equipped with a purging device.

50. The locations and structure of pipeline drainage devices are established by the design organization.

51. Continuous condensate removal through condensing pots, other devices and permanent drainage is mandatory for saturated steam pipelines and dead ends of superheated steam pipelines newly installed in accordance with the requirements of these Rules.

Pipeline equipment

52. Each pipeline shall be equipped with working medium pressure and temperature measuring devices, and in case it is necessary to ensure safe operation:

1) shutoff and control valves;

2) pressure-reducing and safety devices;

3) protection and automation devices;

4) flowmeters, metering orifice plates, metering nozzles and devices for measuring pipeline thermal motions;

5) throttle orifices;

6) supports and hangers;

7) emergency restraints designed to restrict pipelines motions in case of pipe breaks;

8) hydraulic shock absorbers;

9) shutoff devices installed on impulse lines of control and measuring devices (hereinafter referred to as CMD) for limiting leakage in case of pipe break or leakage on CMD impulse lines in unattended rooms;

10) pipeline sampling system line.

The number and location of valves, measuring, automation and protection devices shall be defined by the design organization taking into account the provision of safe maintenance and repair.

53. Safety devices should be designed and adjusted so that the pressure in the protected component does not exceed the permitted pressure more than 10%, and at permitted pressure up to 0.5 MPa - not more than 0.05 MPa.

Overpressure when safety valve is wide open higher than 10% of the permitted pressure can be allowed only if it is provided for in the strength calculation of the pipeline.

Calculation of flow capacity of safety devices shall be performed by the design bureau.

If pipeline operation is allowed at reduced pressure, the alignment of the safety devices shall be based on this pressure, and the flow capacity of the devices shall be verified by calculation.

54. Tapping the working medium from the branches on which safety devices are installed is not permitted. Safety valves shall have discharge pipelines protecting the personnel against burns upon actuation of the valves. These pipeline shall be protected from freezing and equipped with drainages for discharge of collected condensate. Installation of shutoff elements on drains is not permitted.

55. Design of spring-loaded valves shall provide for the device to check operability of the valve in the course of the pipeline operation by its forced opening. In case an electrically-driven pilot-operated relief valve is installed on the pipeline, it shall be equipped with a device enabling remote forced opening of valves from the control panel.

56. The order and timing of testing operability of safety devices, depending on the process conditions shall be specified in the operation manual of pressure-relief devices effective in the operating organization.

Verification of functional capabilities (operability) and setting of the safety devices shall be performed after any repair of the safety devices or the control system affecting the settings but at least once per 12 months (for nuclear power installations - at least once per each fuel campaign).

Works shall be performed in accordance with the work program, and their results shall be recorded in a report.

Verification results for safety devices, information on their adjustment shall be recorded in the shift log sheet of the operating personnel.

Adjustment results for safety devices shall also be recorded in the documentation of the repair personnel who have performed the specified operations.

After safety valves have been adjusted, the adjustment node shall be sealed, and the adjustment information shall be recorded in the shift log sheet of the operating personnel.

If such verification or checking reveals defects or faults in switching the safety devices or control layout, the equipment shall be repaired and re-checked.

57. Pipelines shall be equipped with pressure monitoring devices which can include direct-action devices with in-situ indication (pressure gauges, sensors) or secondary hardware for remote transmission, processing and presentation of pressure data.

58. Pressure monitoring means shall be equipped with the devices protecting them against direct impact of measured media and external factors, as well as with the devices aimed to enable blowdown and drainage of pulse lines.

Layout of the pressure monitoring devices shall provide for the possibility to check their operability, to perform maintenance and repair, or replacement.

Pressure monitoring means and pulse tubes connecting them to the pipeline shall be protected against overheating and freezing in accordance with the design and engineering documentation.

Measurement ranges of the pressure monitoring means shall provide control of the parameters in all modes of operation and have the necessary margin to control the maximum deviations of parameters under emergency conditions.

Measurement errors of pressure monitoring means shall ensure performing measurements in accordance with the accuracy standards defined in the DD.

Measuring instruments are subject to regular verification (calibration).

In case the pressure of the measured medium exceeds 2,2 MPa at least two shutoff valves shall be installed upstream of the pressure monitoring device.

59. The grade of accuracy of pressure gauges shall be at least:

1) 2.5 - for the working pressure of up to 2.5 MPa;

2) 1.5 - for the working pressure exceeding 2.5 MPa and up to 14 MPa;

3) 1.0 - for the working pressure exceeding 14 MPa.

The pressure gauge scale shall be selected so that the pressure gauge needle was located in the scale second third at operating pressure.

Red line indicating the permitted pressure must be on the pressure gauge scale. Instead of the red line a metal plate painted with red and tightly fitted on the pressure gauge glass (or self-adhesive film covering the pressure gauge casing in order to prevent the glass displacement) may be attached to the pressure gauge casing.

The pressure gauge must be installed so that its indications are clearly visible to the operating personnel, and its scale shall be placed in an upright position or with forward pitch not exceeding 30° for improved visibility of the readings.

The nominal diameter of the pressure gauges installed at the height of up to 2 m from pressure gauge observation platforms shall be at least 100 mm, at the height of 2 to 3 m - at least 150 mm and at the height of 3 to 5 m - at least 250 mm.

In case any pressure gauge is located at the height exceeding 5 m a maintenance platform shall be installed in such a way so that the pressure gauge readings could be seen by the operating personnel or a duplicate pressure gauge shall be installed at the height ensuring clear visibility of the indications of the duplicate pressure gauge.

A three-way valve or its substitute device enabling periodical testing of the pressure gauge through the use of a reference pressure gauge shall be installed  between the pressure gauge and the pipeline.

Inspection of the pressure gauge operability by the operating personnel in the course of the pipeline operation shall be performed through the use of a three-way cock or any shutoff valves replacing it by setting of the gauge hand to zero.

Manometers shall be calibrated at least once every 12 months and sealed or stamped accordingly.

In addition, at least once every 6 months the maintenance personnel should perform an additional check of working manometers with a control manometer with recording of the results in the audit log.

In case of lack of the test pressure gauge, it is allowed to perform the additional test by using the tested operating pressure gauge having the identical scale and accuracy class that the pressure gauge under test has.

Pressure gauges shall not be permitted for use in the following cases:

1) there is no seal or stamp with the calibration record on the pressure gauge;

2) the pressure gauge calibration term has expired;

3) the pressure gauge hand will not return to the zero scale mark when it is turned off by more than half of the permissible error for this pressure gauge;

4) glass is broken or there are other damages of the pressure gauge, which may affect the correctness of its readings.

60. Valves shall have clear labelling on their casings with indication of the following:

1) name or trademark of the manufacturing organization;

2) nominal size;

3) nominal medium pressure and temperature (or working pressure and permissible temperature);

4) medium flow direction (in case of any design necessity);

5) casing material grade.

61. Valves with the inner diameter of connecting branches exceeding 15 mm and all safety valves shall be supplied together with certificates and operating manuals for each valve (safety valve) developed by the manufacturing organization.

A certificate for a batch of items may be issued for other valves. The valve certificate shall indicate the materials used, heat treatment regimes, non-destructive testing results if such testing was provided for in the TS. The data shall refer to the main parts of the valve: casing, cover, stem, gate and fasteners.

62. Direction of rotation for the valve opening or closing shall be indicated on the shutoff valve handwheel.

The handwheels of shutoff valves on pipelines shall be painted in accordance with the requirements of the operating organization.

63. A pipeline with the design pressure lower than the pressure of its supply source shall be equipped with a reducing device with a pressure gauge and a safety valve which are installed on the lower-pressure side (pressure-reducing desuperheating devices or other reducing devices).

64. Reducing devices shall ensure automatic pressure regulation, and pressure-reducing desuperheating devices shall also ensure automatic temperature regulation.

65. In order to make it easier to open gates and valves which require a significant torque for opening, as well as for warming up the steam pipelines (in technically substantiated cases), they must be equipped with bypass lines with the diameter determined by the design organization.

III. Materials and semi-finished products

General requirements

66. Any materials and semi-finished products used in manufacturing of steam and hot water pipelines shall assure safe operational parameters determined by their mechanical properties, chemical composition, manufacturing technology, testing and quality control methods and scope, the warranted level of design and process characteristics and shall comply with the requirements of the design and engineering documentation and regulatory documents for the materials.

67. It is permitted to use other materials provided that quality and properties of the materials shall be at least equal to the requirements of the RD and TS and subject to presence of the relevant report (permit, technical solution) of the operating organization approved by the design bureau and the leading material science organization.

68. Information regarding quality and properties of materials and semi-finished products shall be confirmed by the manufacturer of a material or a semi-finished product and by the relevant labeling.

In case of absence or incompleteness of the certification data, the pipeline manufacturing organization, or repair or installation organization shall perform tests in order to define the missing data with recording of their results.

69. When selecting materials for pipelines constructed in cold climate environment, it is necessary to take into account not only the working parameters, but also the impact of low temperatures during operation or assembly, loading and unloading and storage, unless the latter is provided for in administrative and technical actions.

Steel semi-finished products. General requirements

70. The manufacturing organization of semi-finished products shall control the chemical composition of the material. The certificate shall contain the results of chemical analysis obtained directly for the semi-finished product, or the same information on the blank (except for castings) used for its manufacturing.

71. Semi-finished products shall be supplied after heat-treatment. Heat treatment regime shall be specified in the certificate of the semi-finished product manufacturing organization.

It is permitted to supply semi-finished products without heat treatment in the following cases:

1) mechanical and processing characteristics of metal specified in the design and engineering documentation and RD are assured by the semi-finished product manufacturing technology;

2) if the equipment manufacturer subjects semi-finished product to hot forming combined with thermal treatment or to follow-up thermal treatment.

In these instances the manufacturer of semi-finished products shall monitor the properties in thermally treated samples.

Acceptability of semi-finished products without heat treatment shall be confirmed by the main material research organization.

72. The manufacturing organization of semi-finished products shall control mechanical properties of metal by tensile strength testing at 20 °C with determination of breaking stress and 0.2 or 1% proof stress or yield point, relative elongation and relative reduction of area (in case cylindrical samples are tested). Relative contraction values may be provided as reference data. If relative area reduction values are regulated control of relative elongation is not mandatory.

73. In accordance with the requirements specified in the RD, semi-finished products with the sheet thickness, solid forging (casting) thickness and pipe wall or hollow forging (casting) thickness of 12 mm and more and the round bar (forged piece) diameter of 16 mm and more shall be subject to impact testing.

As required by the design development organization, impact testing shall be performed for pipes, sheets and forgers with wall thickness of 6 - 11 mm. This requirement shall be specified in the DD.

74. Metal of the parts for flanged connections of pipelines laid under the open sky, in the ground, in channels or in unheated rooms where metal temperature can be below 0°C as well as metal of other parts upon the engineering organization request specified in the design and engineering documentation shall be subject to impact testing at the temperature of 0°C.

75. Impact tests for the samples with U-type (KCU-type) concentrator shall be performed at -20 °C and in any cases stipulated in par. 73 of these Rules - at one of the temperature values specified in Table No. 3 of these Rules.

Table 3

Impact tests for samples with V-type (KCV-type) concentrator shall be performed in accordance with the design and engineering documentation for semi-finished products at 20 °C, 0 °C and -20 °C.

Impact resistance value calculated as an arithmetical average of three tests shall be at least 30 J/cm² (3.0 kgf · m/cm²) for KCU and 25 J/cm² (2.5 kgf · m/cm²) for KCV. The testing results shall be deemed unsatisfactory in case at least one of the samples has demonstrated the result lower than the established minimum permissible values by more than 10 J/cm² (1.0 kgf · m/cm²).

KCU or KCV impact viscosity criterion shall be selected by the developing organization and specified in the DD.

76. Material of sheet and rolled products for manufacture of fasteners made of carbon, low-alloyed manganese and silico-manganese steels subject to cold forming without subsequent tempering in the course of manufacturing and intended for operation at the temperature of 200 - 350 °C shall be subjected to impact testing after mechanical ageing.

The values of impact viscosity after mechanical ageing shall comply with the requirements of par. 75 of these Rules.

77. Standard values of yield point at elevated temperatures shall be specified in the DD for semi-finished products intended for the parts operated under the design temperature exceeding 150 °C; for carbon and low-alloyed manganese and silico-manganese steels - up to 400 °C, for chromium-molybdenum and chromium-molybdenum-vanadium steels - up to 450 °C and for high-chromium and austenitic steels - up to 525 °C.

Maintenance of yield point values at the level required by the design and engineering documentation shall be assured by adherence to the production technology and regular control of the products. Surveillance tensile strength tests at elevated temperatures prescribed by the design and engineering documentation and also performed in the course of new material assimilation shall be carried out at one of the temperature values within the above-mentioned range divisible by 10 °C or 25 °C. In this case 0.2 or 1% proof stress shall be standardized as an acceptance characteristic and breaking point, relative area reduction or elongation shall be determined as reference data.

78. Material of semi-finished products intended for operation at the design temperature exceeding the values specified in par. 76 of these Rules shall have creep-rupture strength at least equal to the design and engineering documentation requirements.

Warranted creep-rupture strength limits with the operation life of 10⁴, 10⁵, 2 · 10⁵ h shall be substantiated by statistical processing of the test data, regular control of products and confirmed by the opinion of the operating organization, designing organization and the main material research organization.

79. The list of mechanical characteristics control types may be reduced in comparison with the one specified in Tables No. 1 - 6 of Appendix No. 5 to these Rules subject to the the standardized values warranty provided by the semi-finished product manufacturing organization and approved by a specialized organization. Warranties shall be assured by application of statistical processing methods for the data of the manufacturer certificates, testing results (including tensile strength tests) and regular control of the products which shall be specified in the design and engineering documentation.

Sheet steel

Conditions for use of sheet steel and steel strips of various grades and types of mandatory testing and control shall comply with the ones specified in Table No.1 of Appendix No. 5 to these Rules.

Steel pipes

80. Conditions for use of pipes made of various steel grades, the RD for pipes and types of mandatory testing and control shall comply with the ones specified in Tables No. 2 and 3 of Appendix No. 5 to these Rules.

81. Seamless pipes shall be manufactured of rolled, forged or centrifugal-cast blanks.

82. Usage of electric-welded pipes with longitudinal or spiral joints is permitted subject to radiographic or ultrasonic control of the weld seam along the entire length.

83. Each seamless or welded pipe shall be subject to hydraulic testing under the test pressure indicated in the RD for pipes.

The manufacturing organization is permitted not to perform hydraulic testing of seamless pipes in case the complete surface of the pipe is checked by means of physical testing (radiographic, ultrasonic control or equivalent type).

84. Usage of expanded pipes made of any material not checked for impact viscosity after mechanical ageing without subsequent heat treatment for the temperatures exceeding 150 °C is permitted for straight sections provided that plastic deformation in the course of expanding does not exceed 3%.

Steel forged, stamped parts, bar and rolled sections

80. Conditions for use of forged pieces (rolled sections) made of various steel grades, the RD for forged pieces and types of mandatory testing and control shall comply with the ones specified in Table No. 4 of Appendix No. 5 to these Rules.

86. Round bars with the outer diameter of up to 80 mm may be used for manufacturing of parts by cold mechanical processing. Round bars with the outer diameter not exceeding 160 mm may be used for hollow-bored round parts with the wall thickness of not more than 40 mm and the length up to 200 mm. Rolled products are subject to radiographic control or USC within the entire volume in the rolled product manufacturing organization (or in the manufacturing organization of pipelines and their components).

It is permitted to perform radiographic control and USC on finished parts or after preliminary mechanical processing.

87. The limits of application and types of mandatory testing and control for sheet stampings shall comply with the requirements for sheets (Table No. 1 of Appendix No. 5 to these Rules).

Cast steel

88. Conditions for use of steel castings made of various steel grades, the RD for castings and types of mandatory testing and control shall comply with the ones specified in Table No. 5 of Appendix No. 5 to these Rules.

89. The minimal wall thickness of cast pieces after mechanical processing shall be equal to at least the design thickness, but not less than 6 mm.

90. Each hollow-bored cast piece shall be subject to hydraulic testing under the test pressure in accordance with the RD for cast pieces.

Hydraulic testing of cast pieces subjected to complete radiographic control or USC in the manufacturing organization may be combined with testing of the assembly or the whole pipeline at the test pressure specified in the TS for the assembly unit or the whole pipeline.

Fasteners

91. Conditions for use of steel castings made of various steel grades, the RD for castings and types of mandatory testing and control shall comply with the ones specified in Table No. 6 of Appendix No. 5 to these Rules.

92. Materials of fasteners shall be selected with the linear expansion coefficient close to the similar coefficient of the material for flanges; in this case the difference between these coefficients shall not exceed 10%. Steels with different linear expansion coefficients (more than 10%) may be used in cases justified by strength calculations or experimental studies and also in cases when the design temperature of fasteners does not exceed 50 °C during pipeline operation.

93. Fasteners manufactured by cold forming shall be subject to heat treatment - tempering (except for the parts made of carbon steel and operated at the temperature up to 200 °C).

Threading by means of knurling does not require any further heat treatment.

94. Nuts and pins (bolts) shall be made of different steel grades; in case they are made of the same steel grade steel hardness shall be different. In this case the nut hardness shall be less than the pin (bolt) hardness.

The threaded section of pins (bolts) shall exceed above the nut by at least 2-3 turns.

Iron castings

95. Conditions for use of cast-iron castings made of various steel grades, the RD for iron castings and types of mandatory testing and control shall comply with the ones specified in Table No. 7 of Appendix No. 5 to these Rules.

Cast iron pieces may be used to manufacture pipelines referred to safety class 4.

96. Wall thickness of iron castings after mechanical processing shall be not less than 4 mm and not more than 50 mm.

97. Cast pieces made of annealed or high-strength cast iron shall be used after heat treatment.

98. Each hollow-bored cast piece shall be subject to hydraulic testing under the test pressure specified in the design and engineering documentation but at least 0,3 MPa.

99. It is not permitted to use iron castings for valve components subjected to dynamic loads and thermal shocks.

100. Cast pieces made of annealed or high-strength cast iron according to the RD shall be used for manufacturing of shut-off elements, blowdown, discharge and drainage lines.

Non-ferrous metals and alloys

101. The casing parts of valves, cover casings and instrumentation components operated at the temperature not exceeding 250 °C, may be made of bronze and brass.

102. Hydraulic testing of valve casings shall be performed in accordance with the RD.

Requirements to new steel grades

103. Usage of materials and semi-finished products made of new steel grades not specified in RD for manufacturing, repair and refurbishment (upgrade) of pipelines shall be permitted subject to a positive conclusion of the specialized design organization and the leading material science organization approved by the operating organization.

The conclusion shall contain data on the basic mechanical, physical and processing properties of the materials after basic and additional heat treatment.

104. Mechanical properties (breaking point, 1% proof stress for austenitic chromium-nickel steels and 0.2% proof stress for other steel grades) shall be investigated within the range from 20 °C to the temperature exceeding the maximum recommended value by at least 50 °C.

Temperature shall be selected in order to obtain clear dependency between changes of steel strength properties and temperature. Temperature intervals shall not exceed 50°C.

For sheets and pipes the ration between standard values of yield point and breaking point at the temperature of 20 °C shall not exceed 0.6 for carbon steel and 0.7 for alloyed steel. For attach hardware the above-mentioned ratio shall not exceed 0.8.

105. For the materials intended for operation under high temperatures causing creep, experience-based data shall be presented in order to determine the creep-rupture strength values for 10⁴, 10⁵, 2 · 10⁵, 3 · 10⁵ h and conventional creep limit for the temperatures for which it is recommended to use steel.

The number of performed short-term and long-term tests and the duration of the latter shall allow to define steel strength characteristics and to assess their scattering with due regard for the semi-finished product size (wall thickness) and any deviations of mechanical properties (with minimal and maximal values) and chemical composition (metal from the casts with the least favorable content of alloying components in relation to high-temperature strength shall be studied) as specified in the TS.

106. In case steel is prone to structural changes in the course of operation data characterizing these changes and their impact on the steel performance shall be presented.

107. Susceptibility of steel to work hardening shall be assessed on the basis of any changes in its creep-rupture strength and stress-rupture ductility by comparative testing of work-hardened and mild materials.

Material of semi-finished products subject to cold deformation in the course of processing shall be checked for absence of any susceptibility to mechanical ageing.

108. The possibility for steel usage shall be confirmed by the data on its resistance to brittle failures obtained through impact testing or by any other method selected in accordance with the material operation conditions within the product.

109. Welding characteristics of steel for existing types of welding shall be confirmed by testing of weld joints performed in accordance with the applicable technique with use of the relevant welding fillers. Testing results for the weld joints shall confirm their operability and define the effect of welding techniques and heat treatment regime on their operational properties.

Data on creep-rupture strength of weld joints and resistance to local failures in the weld-affected zone during long-term operation shall be presented for heat-resistant materials.

110. When developing new materials it is in some cases necessary to take into consideration their specific operation conditions causing the need to broaden the requirements for assessment of the relevant properties of both steel and its weld joints:

1) for operation under sub-zero temperatures - cold resistance assessment;

2) in case of cyclic loads - cyclic strength assessment;

3) under active impact of media - assessment of corrosion resistance and mechanical strength.

111. The following data on physical properties shall be presented for any new steel grade:

1) modulus of elasticity at various temperatures;

2) the medium-temperature linear expansion coefficient within the relevant temperature range;

3) thermal conductivity coefficient at the relevant temperatures.

112. The manufacturing organizations of semi-finished products or relevant specialized organizations shall confirm that it is possible to make semi-finished products of the recommended steel grade and necessary range while observing the prescribed steel properties.

IV. Manufacturing parts and assembly units.

pipeline installation, adjustment, repair and refurbishment

pipeline (modernization)

General

113. Manufacturing (reworking), installation, technical diagnostics and adjustment of pipelines and their components shall be performed by specialized organizations or the operating organization (pipeline owner) having the conditions necessary for proper performance of the works and trained personnel.

Repair and refurbishment (upgrade) of pipelines may be performed by the pipeline owner or a specialized organization.

114. Pipelines and their components shall be manufacturing by organizations having proper tchnical facilities for ensuring their high-quality production in full compliance with the requirements of these Rules and и ТУ. The DD shall specify the design lifetime of components and assembly units of pipelines (for components of category I and II pipelines).

115. The quality control system (incoming, in-process and acceptance control) assuring performance of the works in accordance with the requirements of these Rules shall be applied in the course of manufacture and installation of pipelines.

The quality control system (incoming, in-process and acceptance control) assuring performance of the works in accordance with these Rules may be applied in the course of repair and refurbishment (upgrade) of pipelines.

116. Manufacturing, installation and repair of pipelines and their components shall be performed in accordance with the technology developed by the manufacturing organization, a specialized installation and repair organization including the pipeline owner, if it performs the works, before the beginning of relevant work. Performance of work in accordnace with the devleoped technology shall ensure high operational reliability of pipelines.

117. The adopted technology for manufacturing installation, repair and refurbishment (upgrade) of pipelines and their components shall be fully represented in the technical documentation (hereinafter referred to as the TD) regulating the content and the procedure of execution of all process and control operations, and execution of the reporting documentation.

In case standards, the TS, control regulations and other documents include all the necessary guidelines for the performance of process and control operations during pipeline repair, it is not necessary to prepare TD.

118. Prior to manufacturing, repair and refurbishment (upgrade) of pipelines, it is necessary to perform incoming control of the main and welding materials and semi-finished products in accordance with the incoming control procedure established by the operating organization, check the availability of extracts from certificates, statements and passports, as well as stamps and factory marks of all pipeline parts and assembly units arriving at the installation site.

119. Labelling of the manufacturing organization shall be preserved on sheets, rolled products and forged pieces intended for manufacture of steam and hot water pipelines as well as on the pipes with the outer diameter exceeding 76 mm.

If the above-mentioned semi-finished products are to be cut into pieces labelling shall be preserved on each of its parts.

120. Boring, flaring or crimping of the pipe ends is permitted to provide proper match of the pipe cross-sectional joints. Permissible values of boring, flaring or crimping deformation shall be specified in the DD.

121. For protection of internal cavities of pipeline parts and assembly units from atmospheric corrosiveness, the internal cavities shall be cleaned, and the openings shall be closed with plugs, casings or other equivalent protection devices prior to their shipment to the place of repair.

122. Pipelines cold draw, if it is provided for in the DD, shall only be carried out after making all welded joints except for the final closing fastening of fixed supports at the end of the section subject to cold draw, and after the heat treatment (if it is necessary) and quality control of weld joints located along the length of the section which shall undergo cold draw.

123. Prior to assembly in blocks or prior to the dispatch from the manufacturing organization to the repair place of pipeline parts parts and components delivered in bulk, all alloy steel parts and components shall undergo metallographic arc spectroscopy.

124. In order to maintain pipelines in operable condition, the operating organization shall perform timely planned and preventive repair, as well as pipeline repair as a result of in-service control, diagnostics and technical examination based on their technical condition.

125. Repair of pipelines shall only be carried out as per a job order.

126. Repair of pipelines and their components under pressure is not permitted.

127. In case of pipeline repair and refurbishment (upgrade) at open sites, welding can be performed at temperatures below 0 °C in accordance with the operating organization RD.

128. Before the commencement of repairs of a pipeline connected to other operating pipelines, the repaired pipeline (pipeline section) shall be separated from them by means of plugs or disconnected with opening its drains. Disconnected pipelines shall be plugged.

129. Plugs used for the pipeline isolation and installed between flanges shall be tested and have labeling (with indication of the design pressure and nominal diameter) and a protruding part (shank) aimed to define presence of the plug.

The thickness of plugs and flanges used in case of pipeline disconnection shall be determined by means of strength calculation.

For welded pipelines where it is impossible to install plugs disconnection of the pipeline shall be arranged through the use of two gate valves installed in series. A drain device connected directly to the atmosphere shall be installed between them. If it is impossible to disconnect the pipeline for repair with two gate valves installed in series  the repaired section may be isolated through the use of one gate valve subject to permit of the chief engineer of the organization. In this case no steaming (leakage) signs through the drain to atmosphere opened for the period of repair works shall be present.

In case the pipelines are isolated with one gate valve from the operating equipment with the water temperature not exceeding 45 °C no permit of the chief engineer is required for such isolation.

In case the procedure for pipeline isolation with the use of one gate valve is described in the process operation instructions for the pipeline or the system which includes the pipeline approved by the chief engineer of the organization, no additional permit is required for performing such work.

130. A repair log sheet shall be kept in the operating organization where the person responsible for operability and safe operation of the pipeline shall record the information on any performed repair works which do not require an unscheduled technical examination.

Information on any performed repair works, materials used for repair, and welding  quality shall be entered into the pipeline certificate.

Welding

131. An attested welding technology developed by the installation organization and approved by the leading material science organization shall be used for pipeline manufacturing and installation.

An attested welding technology developed by the pipeline owner shall be used for pipeline repair.

132. Operable plants, equipment and devices ensuring high-quality welding operations shall be used for welding.

133. Welding operators with licenses for performance of these welding works issued in accordance with the procedure established by the operating organization shall be admitted to perform welding and tacking of pipelines during their manufacturing, repair and refurbishment (upgrade).

Welding operators shall perform only the types of welding works they are admitted to in accordance with the licenses.

134. Any welding operator in the organization who commences welding of pipeline components for the first time shall pass verification by control of correct performance of a test weld joint and evaluation of its quality prior to work authorization. Design of the test weld joint shall correspond to the types of work specified in the welding operator's license.

Methods, scope of control and welding quality assessment standards of the test weld joint shall comply with the requirements of these Rules.

As a result of test weld joint control, a protocol in accordance with the form established by the operating organization is issued which constitutes the basis for admission of a welding operator to performing welding. In case of unsatisfactory quality of the test weld joint, the welding operator cannot be admitted to work.

135. Supervision over the works for assembly, welding and weld joint quality control during manufacturing of parts and assembly units and repair and refurbishment (upgrade) of pipelines shall be assigned to welding specialists checked for knowledge of these Rules in compliance with the procedure established by the operating organization.

136. Welded joints of pipeline components with the wall thickness of at least 6 mm shall be subject to labelling (stamping) enabling to define the surname of the welding operator who has performed welding. The labelling system shall be specified in the process control documentation. Labeling necessity and technique for weld joints with the wall thickness of less than 6 mm shall be established by the PCD requirements.

The labelling technique shall eliminate work hardening, additional heating or unacceptable metal thinning and ensure integrity of the labelling within the entire service life of the item.

In case all weld joints of the item have been performed by the same welding operator it is permitted not to label each weld joint. In this case the welding operator's stamp shall be applied near the nameplate or at any other open section of the item and the labeling place shall be enclosed in a box drawn with indelible paint. The labeling points shall be specified in the product certificate.

In case any weld joint is performed by several welding operators stamps of all welding operators engaged in arrangement of this weld joint shall be applied.

137. Welding materials used for welding of pipelines shall comply with the requirements of the DD and RD which should be confirmed by a manufacturing organization certificate.

138. Grades, assortment, storage conditions and preparation of the welding materials for use shall comply with the PCD and RD requirements.

139. Aside from the check in accordance with paragraph 115 and subparagraph 3 of paragraph 207 of these Rules, the following welding materials shall be checked:

1) each batch of electrodes - for welding and processing properties in accordance with the RD (including for compliance of the alloying component content in the weld metal arranged with the use of alloyed electrodes through chemical composition control by positive material identification test or any other spectrum analysis method used for chemical composition control);

2) each batch of flux cored wire - for welding and processing properties in accordance with the RD;

3) each coil (bundle, bobbin) of alloyed welding wire - for presence of the basic alloying components regulated by RD by positive material identification test;

4) each wire batch with each flux batch which will be used in combination for automatic submerged welding - for mechnanical properties of the joint metal.

140. Preparation of edges and adjacent surfaces for welding shall be performed by mechanical processing or by thermal cutting or gouging (oxygen, air arc or plasma arc) with subsequent mechanical processing with a cutter, miller or abrasive tool. Depth of mechanical processing after thermal cutting (gouging) shall be specified in the TD depending on the particular steel grade susceptibility to the thermal cycle of cutting (gouging).

141. In the assembly of butt joints of pipes with single-side edge preparation and welded without any without backing rings and root backing, displacement (misalignment) of the inside edges shall not exceed the values specified in the process control documentation.

142. Edges of parts to be welded and adjacent areas shall be cleaned from any slag, paint, oil and other contaminants in accordance with the requirements of the technical documentation for welding.

143. Welding and removal of auxiliary components shall be performed in accordance with the drawings and the TD for welding. These components shall be welded on by the welding operator admitted to welding of this item.

144. Track welding of pipeline components assembled for welding shall be performed using the same welding materials as the ones used for welding of these pipeline components.

145. Application of gas welding for any parts made of austenitic steels and high-chromium steels of martensitic and martensitic-ferritic classes in the course of manufacturing, repair or refurbishment (upgrade) of pipelines is not permitted.

146. Pipeline parts and assembly units shall be welded at positive temperature of the ambient air. It is permitted to perform welding works at sub-zero temperatures subject to compliance with requirements of the TD for welding and arrangement of the required conditions for protection of the welding site against any factors affecting the welding quality.

In case of negative temperatures of the ambient air metal in the weld joint area shall be dried and heated prior to welding in order to achieve positive temperature values.

147. Necessity and regime of preliminary and concurrent heating of the welded parts shall be defined by the welding technique and specified in the process control documentation. In case of sub-zero temperature of the ambient air heating shall be arranged in the same cases as for positive one but the heating temperature shall be higher by 50°C.

148. Subsequent to welding the joint and adjacent areas shall be cleaned from any slag, metal splash and other contaminants.

Heat treatment

149. Heat treatment of the pipeline parts and assembly units shall be performed in order to assure compliance of metal and weld joint properties with the parameters specified in the RD and also to reduce residual stresses caused by processing operations (including welding, bending and pressing).

150. There may be two types of heat treatment:

1) basic one including annealing, annealing with tempering, hardening, temper hardening, austenite conditioning and multi-stage heat treatment with heating up to hardening or austenitization temperatures;

2) additional one in the form of tempering.

Types of the basic and additional heat treatment and its regimes (particularly heating rate, holding temperature and time, cooling rate and the cooling medium type) shall be adopted in accordance with the TD in compliance with the requirements of these Rules.

Heat treatment operators having passed theoretical and practical training and  admitted to performance of such work in accordance with the procedure established by the operating organization.

151. Items are subject to basic heat treatment in the following cases:

1) if semi-finished products have not been subjected to heat treatment according to the regimes ensuring the material properties and specified in the RD;

2) if any forming operations have been performed with heating up to the temperature above the tempering temperature;

3) after bending of pipes made of austenitic steel (regardless of the pipe outer diameter and the bending radius);

4) in all other cases when basic heat treatment is prescribed in the TD for manufacturing and welding, and in accordance with the requirements of the design documentation.

152. Basic heat treatment is not mandatory when forming operations have been performed:

1) for parts and semi-finished products made of carbon and manganese and silico-manganese steels with heating up to the annealing temperature not less than 700 °C in the end;

2) for pipes made of austenitic steels in the course of bending on the machines with high-frequency heating up to austenitization temperature with spray cooling;

3) for parts and semi-finished products made of austenitic steels at the temperature of at least 850°C.

153. Items are subject to additional heat treatment (tempering) in the following cases:

1) after expanding and pressing of parts made of carbon, manganese and silico-manganese steels without any heating or with heating below 700 °C if the wall thickness is more than 36 mm, regardless of the bending radius;

2) after bending without heating pipe bends:

a) for pipes made of carbon, manganese and silico-manganese steels with the wall thickness exceeding 36 mm, regardless of the bending radius, or with the wall thickness of 10 to 36 mm and the mean bending radius less than three-fold outer diameter of the pipe in case out-of-roundness of the bend cross-section exceeds 5%;

b) for pipes made of 12H1МF and 15H1М1F steel grades with the nominal outer diameter exceeding 108 mm, regardless of the wall thickness, or with the diameter of 108 mm and less and the wall thickness of 12 mm and more;

c) for pipes made of other alloyed steels in accordance with the technical documentation for welding;

d) for pipes having bends with the cross-sectional out-of-roundness exceeding 5%;

3) after welding of parts and assembly units of pipelines:

a) made of carbon, manganese and silico-manganese steels with the wall thickness exceeding 36 mm and with the wall thickness of more than 40 mm in case of concurrent heating up to the temperature of at least 100 °C;

b) made of other alloyed steel grades in accordance with the technical documentation for welding;

4) after welding of nozzles and any non-pressurized parts to pipelines with the basic part wall thickness exceeding the wall thickness specified in subparagraph 3 (welding without heat treatment is permitted subject to use of the special technique approved by the main material research organization);

5) in all other cases when additional heat treatment or replacement of the basic heat treatment with additional one is prescribed in the product TS or the TD for manufacturing and welding, and in accordance with the requirements of the design documentation.

154. Conditions for the item within the time period from completion of welding to commencement of tempering (including holding time, permissible cooling temperature) shall be determined in the technical documentation for welding. Tempering temperature of a welded item shall not exceed tempering temperature of a semi-finished product.

155. If the prescribed level of mechanical properties for the manufactured component (except for pipe bend) is confirmed by testing the necessity for additional heat treatment as specified in par. 153 of these Rules shall be determined by the Leading material science organization.

156. The necessity for heat treatment and its regime for the components welded of different steel grades shall be defined in the technical documentation for welding.

157. During basic heat treatment of all parts and components as well as additional heat treatment of longitudinal and meridional weld joints the items shall be heated as a whole. Tempering of items in parts shall be permitted subject to assurance of the required structure and mechanical properties along the entire item length as well as absence of any warpage.

158. Local heat treatment is permitted for austenite conditioning of austenitic steel bends and tempering of bends made of carbon, low-alloyed manganese and silico-manganese steel. Simultaneous heating of the entire bend section and the adjacent straight sections with the length at least equal to three-fold pipe wall thickness but not less than 100 mm at each side of the bend shall be provided in the course of local heat treatment for pipe bends.

159. Tempering of cross-sectional weld joints of pipelines as well as weld joints for welding of nozzles, support components, fasteners and other parts to pipelines may be performed by local heating with portable heating devices. Uniform heating along the entire ring perimeter shall be provided in the course of heat treatment for cross-sectional (circular) weld joints. The heating zone width with the weld joint located in the middle of the heated section shall be defined in the process control documentation.

Pipeline sections located near the area heated in the course of heat treatment shall be covered with insulation in order to assure smooth temperature changes along the entire pipeline length.

160. Heat treatment shall be performed in such a way so that to provide uniform heating of metal for the items, its free thermal expansion and absence of any plastic deformations. Heating, holding and cooling regimes in the course of heat treatment for the items with the wall thickness of at least 20 mm and temperatures exceeding 300 °C shall be recorded automatically.

Control of items and weld joints

161. Methods and scope of control of products and welded joints which guarantee identification of defects affecting pipeline operability shall be used during pipeline manufacturing, installation, repair and refurbishment (upgrade).

The welding and weld joint quality control system shall include:

1) proof of personnel knowledge testing;

2) control of assembly and welding, thermal equipment, devices, instrumentation and tools;

3) quality control for the basic materials;

4) in-process control of welding techniques;

5) non-destructive quality control for weld joints;

6) destructive quality control for weld joints;

7) defects remedy control.

162. The following methods shall be used for nondestructive testing of materials and welded joints:

1) visual and dimensional;

2) radiographic;

3) ultrasonic;

4) capillary or magnetic powder;

5) eddy current;

6) steeloscoping;

7) hardness measurement;

8) hydraulic testing.

Apart from the specified methods, other methods may be used within the scope specified in the DD.

The control methods shall be selected in accordance with the requirements of these Rules and the TD for welding, and shall be specified in the DD.

163. Testing of the mechanical properties, metallographic studies and testing for inter-crystalline corrosion resistance shall be performed within the scope of destructive control. The procedure, sequence and scope of control shall be specified in the product DD.

164. Acceptance control of parts, assembly units and weld joints shall be performed after completion of all processing operations associated with the item heating above 450 °C, heat treatment, metal deforming and work-hardening.

Sequence of control by individual methods shall comply with the requirements of the process control documentation. Visual and measuring control and also positive material identification test shall precede any other methods of control.

165. Control methods and scope shall be specified in the DD.

Welded joint control shall be performed in accordance with standardized unified control procedures or the operating organization procedures. The operating organization procedures, in case of any deviations from the standardized unified control procedures, shall be approved by the leading material science organization.

Specialists having passed special theoretical and practical training and proficiency verification and duly admitted to perform the works in accordance with the procedure established in the regulatory documents shall carry out control of weld joints.

166. In the course of works it is necessary to arrange in-process control of the preparation and assembly of parts for welding, welding and heat treatment of weld joints, elimination of defects in weld joints.

Adherence of the workers to the requirements of these Rules, technical documentation and drawings shall be checked in the course of in-process control. The scope of in-process control in the course of preparation, assembly, welding, heat treatment and elimination of defects shall be specified in the technical documentation.

167. Results for each type of control (including in-process one) and point of control shall be registered in the reporting documents.

168. Means of control shall undergo metrological calibration in compliance with the RD.

169. Each batch of defectoscopy materials shall be subject to incoming control prior to use.

170. The scope of destructive and non-destructive tests specified in these Rules may be reduced subject to approval of the operating organization and the design organization.

171. Control methods and scope for weld joints of weld-on parts not intended for operation under internal pressure shall be specified in the technical documentation for the item and for welding.

172. The item shall be deemed suitable in case no internal and external defects exceeding the acceptable limits established by these Rules (Appendix No. 3) and the RD for product and welding.

Visual and measuring control of product, tollerances

173. After manufacturing, repair or refurbishment (upgrade), each item and all its weld joints shall be subjected to visual and measuring control conducted in accordance with these Rules, the DD and the TD in order to reveal external defects including:

1) any deviations of physical dimensions and mutual alignment of the components;

2) surface cracks of all types and directions;

3) defects on the surface of basic metal and weld joints.

174. Prior to visual control surfaces of the item and weld joints shall be cleaned from any contaminants and slag. The surface of the weld joint and the adjacent sections of basic metal with the width of at least 20 mm on both sides of the weld joint (or 100 mm in case of slag welding) shall be cleaned for control of weld joints.

175. Visual and measuring control of weld joints shall be performed on the exterior and interior side along the entire pipeline length according to the technical documentation.

In case the inner surface of the weld joint is not accessible for visual and measuring control it shall be performed only on the exterior side.

176. Any surface defects revealed in the course of visual and measuring control shall be eliminated prior to control by any other non-destructive methods.

177. Allowances for physical dimensions of finished items shall not exceed the values specified in the RD and drawings and shall not exceed the values established in these Rules.

The procedure and quantity of check measurements and location of the controlled areas shall be defined in the process control documentation.

178. In cylindrical and conical components made of sheets or forgings (stampings) with the use of welding:

1) following deviations may be allowed:

a) for the diameter - not more than 1% of the nominal outer or inner diameter;

b) for cross-sectional out-of-roundness - not more than 1%; out-of-roundness shall be calculated in accordance with the following formula:

where D_max, D_min are the maximal and the minimal outer and inner diameters measured in the same cross-section;

c) from the generatrix alignment - not exceeding 0.3% of the whole length of the cylindrical component section, and for any section with the length of 5 m;

2) no local thinnings shall reduce the wall thickness beyond the permissible limits;

3) depth of dents and any other local shape deviations shall not exceed the values substantiated by strength calculations.

179. Deviations of the diameter and cross-sectional out-of-roundness for pipeline components shall not exceed the values specified in the product RD.

180. Wall thickness of bent pipe sections shall be controlled through the use of an ultrasonic thickness gauge or by measurement after cutting performed selectively for a batch of bent sections with the same dimensions. The procedure, sequence and scope of wall thickness control for bent sections of pipes shall be specified in the process control documentation.

181. The maximum permissible displacement (misalignment) of the edges of welded components (parts) on the exterior side of the joint in butt weld joints with the same nominal wall thickness shall not exceed the values specified in Table 4 of these Rules.

Table No. 4

182. Displacement (misalignment) of edges of components (parts) in butt weld joints with single-side edge preparation on the interior side of the joint (on the weld root side) shall not exceed the standards established by the technical documentation and working drawings.

In butt weld joints performed by double-sided arc welding as well as by slag welding the above-mentioned displacement of edges shall not be exceeded on both exterior and interior side of the joint.

183. The requirements specified in par. 18 and 182 of these Rules shall not be mandatory for weld joints of components with different actual wall thickness provided that smooth transition from one cross-section to another is arranged by inclination of the coupling surface in accordance with the requirements of par. 26 of these Rules.

In case edges of welded components (parts) are displaced within the limits specified in par. 181 and 182 of these Rules the joint surface shall provide smooth transition from one edge to another.

Radiographic and ultrasonic control

184. Radiographic and ultrasonic control methods shall be used to detect any internal defects of weld joints, delamination and cracks in the base metal, wall thickness control of pipeline parts and assembly units.

Control methods shall be applied in accordance with paragraph 162 of these Rules and the TD.

185. Radiographic and ultrasonic control of weld joint quality shall be performed in accordance with the technical documentation.

186. The following parts of pearlite and martensite-ferrite grade pipelines (and their components) are subject to compulsory ultrasonic control:

1) all butt weld joints of category I and II pipelines with wall of thickness of 15 mm and more - along the whole joint length, except for weld joints of cast components;

2) weld joints which are subject to ultrasonic control in accordance with their TD for welding.

All weld joints of pipes shall be controlled by means of ultrasonic testing to both sides of the seam axis, and weld joints of pipes with cast or other shaped components - to one side (the pipe side).

Full-penetration joints (without any constructive lack of penetration) shall be subject to ultrasonic control.

187. The following joints on the pipelines made of pearlite and martensitic-ferritic steels shall be subject to mandatory ultrasonic control:

1) all longitudinal weld joints of pipelines of all categories, their parts and components - along the whole length of the joints;

2) all category I transverse weld joints of pipelines with the outer diameter of 200 mm and more and the wall thickness of less than 15 mm - along the entire length of joints;

3) transverse butt weld joints of category I pipelines with the outer diameter of less than 200 mm and the wall thickness of less than 15 mm, as well as category II pipelines with the outer diameter of 200 mm and more and the wall thickness of less than 15 mm - in the amount not less than 20% (but not less than five butt joints) of the total number of similar butt joints on each pipeline performed by each welding operator (along the entire length of joints);

4) transverse butt weld joints of category II pipelines with the outer diameter of less than 200 mm and the wall thickness of less than 15 mm in the amount not less than 10% (but not less than four butt joints) of the total number of similar butt joints on each pipeline performed by each welding operator (along the entire length of joints);

5) transverse butt weld joints of category III pipelines III in the amount not less than 5% (but not less than three butt joints) of the total number of similar butt joints on each pipeline performed by each welding operator (along the entire length of joints);

6) transverse butt weld joints of category III pipelines IV in the amount not less than 3% (but not less than two butt joints) of the total number of similar butt joints on each pipeline performed by each welding operator (along the entire length of joints);

7) all angle weld joints of pipeline parts and components with the inner diameter of the welded-on fittings (pipes, branch pipes) of 100 mm and more regardless of the wall thickness - along the entire length of checked joints;

8) angle weld joints of pipeline parts and components with the inner diameter of the welded-on fittings (pipes, branch pipes) of less than 100 mm, transverse butt weld joints of cast pipe components with cast parts (see subparagraph 1 of paragraph 186 of these Rules) as well as other welded joints not specified in this paragraph - in the amount specified by the TD for welding.

The control scope requirements provided in subparagraphs 5 and 6 of paragraph 187 of these Rules apply to welded joints of category III and IV pipelines with the outer diameter not exceeding 465 mm. For welded joints of pipelines with larger diatmers, scope of control shall be determined by the pipeline TS and TD for welding.

The requirements for control of butt weld joints of pipeline components positioned at an angle of less than 60° to the pipeline's longitudinal axis shall comply with the requirements for longitudinal weld joints; weld joints with larger angle values shall be considered transverse weld joints.

The control procedure (ultrasonic or radiographic control) for the weld joints specified in this paragraph is defined by the design and engineering documentation and technical documentation and shall be selected on the basis of the possibility to assure more complete and accurate detection of inadmissible defects with due regard for peculiar physical properties of metal as well as excellence of the control procedure for this type of weld joints on particular items.

188. Radiographic control is mandatory for all crossings of longitudinal and transverse pipeline butt welds subject to ultrasonic control in accordance with paragraph 186 of these Rules.

189. Transverse butt weld joints of welded sector bends (elbows) for category III and IV pipelines shall undergo ultrasonic control or radiographic control in the triple scope in comparison to the requirements specified in subparagraphs 5 and 6 of paragraph 187 of these Rules using a doubled quantity of the minimum number of controlled butt welds.

190. The following joints on the items made of austenitic steels as well as at the coupling sites between components made of austenitic steels and components made of pearlitic and martensitic-ferritic steels shall be subject to mandatory radiographic control:

1) all butt weld joints of pipeline components except for the ones performed by resistance welding - along the entire joint length;

2) all butt weld joints of cast components as well as pipes with cast components - along the entire joint length;

3) all angle joints of pipeline parts and components with the inner diameter of the welded-on fittings (pipes, branch pipes) of 100 mm and more regardless of the wall thickness - along the entire joint length;

4) other weld joints (including angle ones) not specified in this paragraph - in the amount not less than 3% (but not less than two butt joints) of the total number of similar butt joints on each pipeline performed by each welding operator (along the entire joint length).

191. In case of simultaneous manufacturing or installation of several pipelines (or parts or components for different pipelines) with similar weld joints controlled in the amount of less than 100%, on one AEUF, it is permitted to define the scope of control not for one pipeline, but for the whole pipeline batch (series, group). Pipelines may be included in one batch if their manufacturing cycle in terms of assembly and welding activities, heat treatment and welded joint quality control does not exceed 3 months.

In case of pipeline installation such permission may only be applied if all welding of the corresponding similar welded joints at the site is conducted by one organization.

192. Welded joints of components made of alloyed heat-resistant steels of pearlite class and performed at the temperature of less than 0 °C without any preliminarily or accompanying heating in the welding area shall be checked by radiographic or ultrasonic control along the entire length of weld joints.

193. Butt weld joints subjected to repair re-welding shall be checked by radiographic or ultrasonic control along the entire length of weld joints. Areas repaired through the use of gouge welding shall be checked by radiographic control or USC across the entire sections including heat-affected zone in the basic metal. The surface of the section shall be also checked by magnetic powder or capillary inspection. In case of seal welding across the entire wall thickness surface shall be controlled from both sides except for the cases when the interior side is inaccessible for control.

194. In case it is impossible to carry out ultrasonic or radiographic control due to inaccessibility of individual weld joints (particularly weld-on seams of nozzles and pipes with the inner diameter of less than 100 mm) or in case these control methods are inefficient, quality control for these weld joints in the course of manufacturing, repair or refurbishment (upgrade) of pipelines shall be performed through layer-by-layer visual inspection in the course of welding with registration of the control results in the special-purpose log sheet and subsequent control of the weld joint within the scope of 100% by capillary or magnetic powder method.

195. In case of selective control, choice of controlled weld joints shall be performed by the AEUF technical control department out of the most difficult joints or doubtful joints subsequent to the results of visual and measuring control.

196. In case any inadmissible defects are detected in the course of selective control of the weld joints performed by any welding operator all similar weld joints performed by this welding operator on the pipeline within the period that has passed from the previous control of the item weld joints by the same method shall be subject to control along the entire length.

Capillary and magnetic powder control

197. Additional types of testing established by the DD in order to detect any surface or sub-surface defects are capillary and magnetic powder control of welded joints and products.

198. Capillary and magnetic powder control shall be performed in accordance with the control procedures approved for application by the engineering (design) organization, the main material research and operating organizations.

199. Class and sensitivity level of capillary and magnetic powder control shall be specified in drawings and the technical documentation.

Positive material identification test

200. Positive material identification tests shall be performed in order to confirm compliance of metal alloying for parts and weld joints with the requirements of drawings and the technical documentation.

201. The following items shall be subject to positive material identification tests:

1) all welded parts (structural elements) to be made of alloyed steel in accordance with the drawing;

2) weld metal of all pipeline weld joints to be performed with the use of alloyed filler in accordance with the RD (TD);

3) welding materials in accordance with paragraph 139.

202. Metallographic arc spectroscope during pipeline manufacturing and installation shall be conducted in accordance with the RD or the instructions approved by the operating and leading material science organizations.

Hardness measurement

203. Weld joint metal hardness measurement is performed in order to check quality of heat treatment for weld joints.

204. Metal of weld joints of pipeline components made of alloyed heat-resistant steels of pearlitic and martensitic-ferritic classes shall be subject to hardness measurement through the use of methods and within the scope specified in the RD.

Mechanical testing, metallographic studies

and inter-crystalline corrosion resistance tests

205. Mechanical tests shall be performed in order to check compliance of the mechanical characteristics and quality of weld joints with the requirements of these Rules and the RD.

Metallographic studies shall be performed in order to detect any potential internal defects and also sections with metal structure deteriorating the properties of weld joints and products. Mictrostructure studies are mandatory for gas welded joints control, for certification of welding technology and in other cases provided for in the RD for welding.

Inter-crystalline corrosion resistance tests shall be performed in any cases stipulated for in the design and engineering documentation in order to confirm corrosion resistance of weld joints on the parts made of austenitic steels.

Mechanical tests, intergranular corrosion resistance tests and metallographic studies shall be performed in accordance with the RD.

206. Mechanical tests shall be performed:

1) for the welding technique validation;

2) for control of manufacturing butt weld joints performed by gas and resistance welding;

3) during incoming control of welding materials used for flux and slag welding.

207. Metallographic studies shall be performed:

1) for the welding technique validation;

2) for control of manufacturing butt weld joints performed by gas and resistance welding and for components made of steels with different structural classes (regardless of the type of welding);

3) to control manufacturing corner and T-shaped weld joints particularly joints between pipes (nozzles) and pipelines as well as tee joints.

208. The main types of mechanical tests include static tension tests, static bending tests or flattening and impact bending tests.

Static tension tests are not mandatory for manufacturing cross-sectional weld joints subject to complete radiographic control or USC of these joints.

Impact viscosity tests are not mandatory for manufacturing weld joints of category II, III and IV pipes and components as well as for all weld joints of the parts with the wall thickness of less than 12 mm.

209. Metallographic studies are not mandatory:

1) for weld joints on parts made of pearlitic steel subject to complete radiographic control or USC of these joints.

2) for the weld joints and pipelines performed by resistance welding with the use of special-purpose machines for resistance butt welding with automated operation cycle subject to the machine adjustment quality check on a shift basis through reference sample testing.

210. Check of mechanical properties, metallographic tests and intercrystalline corrosion tests shall be carried on samples made of reference weld joints (defined in accordance with Appendix No. 2 to these Rules) or manufacturing weld joints cut out of the item.

211. These reference welds must be identical to the controlled manufacturing welds. Reference joints shall be performed in full compliance with the process applied for welding of manufacturing joints or production validation of the technique. Heat treatment of the reference joints shall be performed together with the item (for common heat treatment in the furnace) and in case it is impossible - separately through the use of heating and cooling methods and temperature regimes specified in the process control documentation for manufacturing joints. In case controlled weld joints are subjected to repeated heat treatment the reference joint shall be subjected to the same number of heat treatments under the same regimes. In case a manufacturing joint is subjected to repeated high-temperature tempering the reference joint may be subjected to single tempering with the holding time of at least 80% of the total holding time in the course of all high-temperature temperings of the manufacturing joint.

212. Reference weld joints shall be arranged as:

1) butt joints of two pipe sections - to control pipeline welds;

2) corner or T-shaped joints between nozzles (pipe sections) and the main pipes - to control welding of nozzles to pipelines or headers and also for tee joints.

213. The reference weld joint shall be completely checked by the same non-destructive control methods as provided for manufacturing weld joints. In case the control results are unsatisfactory the reference joints shall be manufactured again in double quantity. In case the results of repeated non-destructive control are unsatisfactory the general result shall be also deemed unsatisfactory. In this case quality of materials, equipment and qualification of the welding operator shall be subject to additional check.

214. The number of controlled joints for all similar manufacturing joints performed by each welding operator within six months (particularly for different orders) checked in accordance with subparagraph 2, par. 206 and subparagraph 2, par. 207 of these Rules shall be at least one, unless increased number of reference joints is prescribed in the technical documentation. In case of any off-the-job period for any welding operator exceeding three months a new reference weld joint shall be made.

When controlling cross-sectional joints of pipes performed by resistance welding at least two reference joints shall be tested for all identical manufacturing joints welded on each welding machine with automated operation cycle within a shift and in case of the machine readjustment during a shift - within the period between readjustments.

When controlling cross-sectional joints of pipes with the nominal size of less than 100 mm and the wall thickness of less than 12 mm performed on special-purpose machines for resistance welding with automated operation cycle and the machine and instrument adjustment quality check on a shift basis through accelerated reference sample testing it is permitted to test at least two reference weld joints for the products manufactured within the period not exceeding three days provided that pipes with the same dimensions and the same steel grades are welded under constant conditions with identical end preparation.

215. Dimensions and quantity of reference joints shall be sufficient to manufacture a set of samples for testing. The minimal number of samples for each type of testing shall be the following:

1) two samples for static tension testing;

2) two samples for static bending testing;

3) three samples for impact bending testing;

4) one sample (thin section) for metallographic studies to control weld joints made of carbon and low-alloyed steel and at least two - to control weld joints made of high-alloyed steel in cases prescribed by the process control documentation;

5) two samples for inter-crystalline corrosion resistance testing.

Static bending testing of reference joints on pipes with the outer diameter not exceeding 108 mm may be replaced with flattening testing. Flattening tests shall be performed in the cases prescribed in the technical documentation.

216. If the results of any mechanical test are unsatisfactory the test can be repeated for a double number of samples cut from the same reference weld joints for the type of testing which has given unsatisfactory results.

In case parameters not complying with the established standards are obtained for at least one of the samples in the course of repeated testing the general results of this testing type shall be deemed unsatisfactory.

In case it is impossible to cut samples out of the first reference joint (set) the second reference joint (set) may be welded in accordance with the above-mentioned requirements.

Quality assessment standards

217. The quality control system shall be applied in order to eliminate any defects deteriorating reliability beyond the limits ensuring safe operation of the pipeline.

218. Allowances for dimensions of the finished items shall comply with the requirements of the RD.

219. Quality of weld joints shall comply with the quality assessment standards for weld joints stated in Appendix No. 3 hereto.

Hydraulic pressure tests

220. Hydraulic test aimed at verification of tightness and strength of pipelines, their components, as well as all weld and other joints shall be performed for:

1) all pipeline parts and components; hydraulic testing is not mandatory if they were subjected to 100% ultrasonic control or testing by any other equivalent non-destructive flaw detection method;

2) pipeline assemblies; hydraulic testing is not mandatory if all of their constituent components were subjected to testing in accordance with subparagraph 1 of this paragraph, and all the welded joints performed during their manufacturing by means of non-destructive flaw detection testing (ultrasonic or radiographic control) along their entire length;

3) pipelines of all categories with all their components and valves after completion of installation.

221. Hydraulic testing of individual and assembled components together with the pipeline is permitted in case it is impossible to test them separately under the conditions of manufacturing or installation of the pipeline.

222. The minimum testing pressure value for hydraulic testing of pipelines, their assemblies and separate components shall be equal to at least 1.25 of the operating pressure, but not less than 0.2 MPa.

The maximum testing pressure value is determined by strength calculation in accordance with the RD.

Valves and fittings of pipeline shall be subjected to hydraulic testing at the test pressure in accordance with the RD.

223. Hydraulic testing shall be performed using water with the temperature of not less than 5 °C and not more than 40 °C.

Pipeline hydraulic testing shall be performed at positive temperature of the ambient air. In case of hydraulic testing of steam pipelines operated with pressure 10 MPa and more, the temperature of their wall shall be not less than 10 °C.

224. The pressure in the pipeline shall be increased gradually. Pressure increase rate shall be specified in the DD for pipeline manufacturing.

It is not permitted to use compressed air to raise pressure.

225. Testing pressure should be measured by two manometers. The manometers are to be of the same type, with identical accuracy class, measurement limit and scale interval.

The holding time of the pipeline and its components under the test pressure shall be at least 10 minutes.

After the test pressure has been reduced to the operating pressure, the pipeline shall be thourougly inspected along the entire length.

Temperature difference between metal and the ambient air shall not cause any moisture condensation on the pipeline surfaces. The water used for hydraulic testing shall not contaminate the pipeline or cause intensive corrosion. Hydraulic testing of pipelines after their installation shall be performed after post-installation cleaning (flushing).

226. The pipeline and its components are considered to have passed the hydrostatic pressure test if the following is not detected: leakage, sweating in welded joints and base metal, visible residual deformations, cracks or signs of rupture.

227. Hydraulic tests of pipelines with pressure not exceeding 10 MPa can be substituted with pneumatic tests (compressed air, noble gas or mix of air and noble gas), subject to control of this testing by acoustic emission.

Test pressure in case of pneumatic tests shall be calculated according to the following formula:

,

where P is the operating pressure.

In case brittle failure is more likely in case of a pneumatic test than under operating conditions, and its consequences pose a significant danger, the test pressure can be reduced to a technically justified level, but not less than the operating pressure.

The pipeline hold-up under the testing pressure during a pneumatic test shall be not less than 15 minutes and shall be specified in the TD.

Subsequent to hold-up under the testing pressure the pressure shall be reduced to the value substantiated in the strength calculations but at least equal to the working pressure and visual inspection of the exterior surface and a leak-tightness examination of all weld and detachable joints shall be performed.

Elimination of defects in welded joints

228. Any inadmissible defects revealed in the course of manufacturing, installation, repair, testing and operation shall be eliminated with subsequent control of the repaired areas.

229. Defect elimination techniques and the control procedure shall be specified in the TD developed in accordance with the requirements of these Rules and the RD.

Deviations from the adopted defect elimination technique shall be approved by its developer.

230. Defects shall be eliminated mechanically with arrangement of smooth transition at the weld defect elimination sites. Maximum sizes and shape of gouges to be welded shall be established in the process control documentation.

Thermal cutting (gouging) techniques may be used for removal of internal defects with subsequent mechanical processing of the weld defect elimination surface.

Completeness of defect elimination shall be checked visually and by non-destructive control methods (capillary or magnetic powder control or etching) in accordance with the technical documentation requirements.

231. Elimination of defects without any weld-up of the defect elimination sites is permitted subject to maintenance of the minimum permissible wall thickness at the maximum gouging depth point.

232. In case any defects are revealed during control of the repaired section repeated elimination of defects may be performed in accordance with the same procedure as the first one.

Elimination of defects at the same section of a weld joint may be performed not more than three times.

Joints cut along the weld seam with removal of weld metal from the heat-affected zone determined in accordance with the design and engineering documentation shall not be considered as repeatedly repaired.

In case a defective weld joint of pipes is cut out and then an insert in the form of a pipe section is welded in the two newly performed weld joint shall not be considered as repaired. The additional butt weld shall be recorder in the pipeline certificate.

V. Technical examination, permit

for operation

Technical examination

233. Pipelines covered by these Rules shall be subject to technical examination after installation prior to putting into operation, regularly in the course of operation and also to unscheduled technical examination in case of necessity.

Primary technical examination of pipelines shall be conducted prior to their registration.

Technical examination includes checking of the documentation, exterior inspection of the pipeline, hydraulic testing and recording of the technical examination results.

234. Technical examination of pipelines shall be carried out by the commission for technical examination of pressurized equipment and pipelines appointed by the order or instruction of the operating organization head (hereinafter referred to as the technical examination commission).

The technical examination commission shall include:

1) the employee of the operating organization appointed by the company-wise organizational and administrative act in order to perform surveillance of technical condition and operation of pipelines (hereinafter - the surveillance (control) person);

2) the person responsible for operability and safe operation of this particular pipeline;

3) other workers of the operating organization as well as workers of a specialized enterprise, the installation organization which performed the works, and any other organizations (in case of necessity).

235. Unscheduled technical examination of pipelines in operation shall be performed in the following cases:

1) if the pipeline has been out of operation for over two years;

2) if the pipeline has been dismantled and installed at a new place;

3) if any bulges or dents have been eliminated, or the pipeline refurbishment (upgrade) or repair with the use of welding of pressurized components has been performed;

4) prior to application of the protective coating on the pipeline walls;

5) after an accident with the pipeline or its components in case such technical examination is necessary within the scope of the restoration works;

6) upon the request of the surveillance (control) person and any other members of the technical examination commission.

236. The pipeline technical examination procedure, the methods used and the standards for non-acceptance shall be established by the operating organization taking into account the requirements of these Rules and shall be recorded in the operation documentation.

Technical examination shall be performed with the following frequency:

1) external examination and hydraulic tests of pipelines of all categories – after the installation prior to the start-up of a newly installed pipeline;

2) external examination (in the process of operation, without removal of heat insulation) of pipelines of all categories – at least once a year;

3) external examination of pipelines (with partial removal of heat insulation) – at least once in three years;

4) external examination and hydraulic tests of pipelines of all categories after repair related to welding and after the start-up of pipelines in case they have been in preservation for over two years.

237. The operating organization administration shall prepare pipeline for technical examination.

238. Prior to external examination and hydraulic tests, the pipeline shall be shut down, cooled, the working medium shall be drained, and plugs isolated from all pipelines connecting it to the pressure source or any other pipelines.

It is permitted not to disconnect a pipeline prior to hydraulic testing from connecting pipelines if their design pressure is not less than the hydraulic testing pressure of the tested pipeline, and there are no technological limitations regarding the filling and pressure increase in such pipelines.

239. Technical examination of any pipelines inaccessible (or accessible to the limited extent) for regular control due to their design peculiarities, radiation situation or any other reasons shall be performed through the use of remote devices and non-destructive methods for control of metal and weld joints. In each particular case for such pipelines, technical examination instructions shall be developed.

240. An external examination shall include:

1) for primary technical examination - a check that the pipeline has been installed and equipped in accordance with the DD, these Rules and the documents provided for registration, and a check that the pipeline and its components are free of damage;

2) in the course of regular and unscheduled technical examinations - a check of operability of the pipeline and possibility for its further operation.

Pipelines shall be presented for hydraulic testing with all valves installed subject to complete readiness for installation in accordance with the design documentation.

241. External examination of pipelines laid openly or in passable and semi-passable channels may be performed without insulation removal. External examination of pipelines in case of non-passable channels or non-channel laying shall be performed by opening the soil layers at separate locations and removing at least 2 meters of insulation not less than every 2 kilometers along the pipeline length.

The person performing technical examination may demand complete or partial removal of insulation in case of doubt in respect of the condition of walls or welded joints.

242. The newly installed pipelines shall be subjected to external examination and hydraulic testing prior to application of insulation.

243. Hydraulic testing of pipelines may only be performed after the end of all welding, heat treatment operations, as well as after installation and final fastening of supports and suspensions. It is necessary to provide documents confirming the quality of the executed work for that (certificate of assembly, pipeline certificates).

Hydraulic testing of pipelines shall be performed in accordance with the requirements specified in sections IV and V of these Rules, and the test pressure value shall be taken in accordance with paragraph 222 of these Rules.

244. For hydraulic testing of pipelines located at the height of over 3 m, it is necessary to  provide service platforms and other means ensuring safe pipeline inspection.

245. In case of quality control of a butt weld connecting the pipeline with an active pipeline (if there is only one shutoff gate between them, and in case of testing of over two repair weld joints), hydraulic testing may be substituted by control of the weld joint by two other types: radiographic and ultrasonic testing.

246. In case any defects decreasing the strength of the pipeline are identified in the course of examination, further operation of the pipeline with reduced parameters (pressure and temperature) may be permitted based on the results of the performed technical examination. The possibility to operate the pipeline with reduced parameters shall be confirmed by strength calculations performed by the design organization or an expert organization.

247. In case the technical examination commission or the person conducting the technical examination of the pipeline identifies pipeline defects for which it is not possible to establish the reasons and consequences, the operating organization administration shall conduct studies in order to identify the reasons for the identified defects.

248. The date of the next scheduled pipeline technical examination shall be established by the operating organization administration with a frequency not less than the one specified in paragraph 236 of these Rules. In case of necessity to engage any specialists from external organizations the operating organization shall inform them on the technical examination date in advance. Pipeline operation shall be stopped not later than the date of a subsequent technical examination specified in the pipeline passport.

Technical examination results shall be recorded in the technical examination certificates, with protocols of pressure testing attached.

Based on this certificate, the operating organization shall make a decision about the possibility and conditions of further operation and the date of the next technical examination, with making relevant entries in the pipeline certificate. An entry shall be made by the technical examination commission and signed by the commission members.

In case of any unscheduled technical examination the reason for such examination shall be recorded in the pipeline certificate.

In case any additional testing and studies are carried out in the course of technical examination types and results of these tests and studies shall be recorded in the pipeline certificate with indication of the sampling points or sections subjected to testing and also the reasons for additional testing.

In case technical examination of the pipeline indicates that it is in a critical condition or detects any considerable defects that cast any doubt about its strength or any defects, further operation of this pipeline shall be stopped, and the reasons why operation was stopped shall be recorded in the certificate.

249. Upon termination of the design service life (design lifetime) pipeline shall either undergo technical examination according to the procedure approved by the operating organization, or be disassembled. The technical examination shall be performed by experts certified to perform non-destructive testing.

250. In case it is impossible to present the pipeline for technical examination within the scheduled time limits due to production conditions the operating organization management shall perform it ahead of schedule.

The technical examination time limits may be extended via an organizational and administrative act of the operating organization but not more than by three months with due regard for technical condition of the pipeline based on the results of the previous technical examination.

251. In case it is defined by analysis of the defects revealed in the course of the pipeline technical examination that their occurrence is related to the pipeline operation mode in this operating organization or characteristic for this pipeline design, the operating organization administration shall arrange unscheduled technical examination of all pipelines installed in this organization and operated under the same mode or all pipelines of the same design respectively.

252. After primary technical examination, pipeline conformity assessment shall be performed in the form of registration according to the requirements of Federal standards and rules in the field of nuclear energy use governing rules of compliance assessment of safety-related products in the field of nuclear energy use.

Pipelines registered prior to entry of these Rules into force shall not be subject to re-registration.

VI. Operation

Arrangement of operation

253. In order to maintain steam and hot water pipelines in operative condition and ensure safe conditions for its operation, the operating organization administration shall:

1) appoint by an organizational/executive directive a surveillance (control) person (or persons) from among the specialists trained and checked for knowledge of these Rules in accordance with the procedure established in the operating organization; the number of surveillance (control) persons shall be defined on the basis of calculations of time required for timely and proper performance of duties assigned to these persons according to the job description;

2) appoint by an organizational/executive directive a person responsible for good operating condition and safe operation of pipelines from among the specialists checked for knowledge of these Rules in accordance with the procedure established in the operating organization (it is acceptable to appoint one person responsible for good operating condition of pipelines and another – for safe operation of pipelines);

3) provide technicians and engineers with the necessary documentation for safe pipeline operation;

4) assign the necessary number of maintenance personnel from among the employees who have obtained certificates for the right of pipeline maintenance;

5) develop and approve the instruction for the pipeline operating personnel; the instruction shall be issued to the maintenance personnel under signed receipt and posted up at the workplaces;

6) establish a procedure in which the personnel responsible for pipeline maintenance carefully monitors the state of the assigned pipeline by means of examination, inspection of operable condition of valves, instrumentation, safety and shutoff devices and records the results of examination and checks into the shift (in-service) log sheet;

7) arrange for periodical examination of the personnel's knowledge (the procedure and frequency for checking of knowledge of personnel are specified in paragraph 258 of these Rules);

8) ensure that engineers and technicians comply with these Rules, regulations and instructions, and the maintenance personnel –with the instructions in accordance with the RD;

9) establish a procedure and ensure the frequency of check of knowledge of the managers, technicians and engineers in the sphere of codes, standards, and instructions on labor protection and industrial safety;

10) ensure the performance of pipeline technical examinations and diagnostics.

254. Control over safe operation and serviceable condition of organization (shop, division) pipelines shall be assigned by an organizational/executive directive of the head of the operating organization to the superior of the pipeline maintenance personnel. The number and date of the act on appointment of the person in charge shall be specified in the pipeline certificate.

During vacations, business trips, sick leaves or in any other cases when the person in charge is absent performance of his/her duties shall be assigned by an organizational and administrative act to any other worker checked for knowledge of these Rules. In such cases no records shall be made in the pipeline certificate.

Maintenance

255. Persons not younger than 18 years old who have no medical contra-indications, have been trained under a relevant program and certified in accordance with the procedure established by the operating organization may be admitted to pipeline maintenance.

256. Training of the pipeline maintenance personnel shall be carried out in training centers as well as at special courses in organizations (including the organization - the owner of the pipeline) provided that they have the necessary conditions for training.

Knowledge checks shall be carried out by the commission of the operating organization; composition of the commission shall be defined in the organizational and administrative act of the operating organization.

No individual personnel training is permitted.

Knowledge checks and documentation of the results of such checks shall be performed in accordance with the procedure established by the operating organization.

257. Results of the exams and regular operating personnel's knowledge checks shall be registered in the protocol signed by the commission chairman and members. The procedure for documentation of the results of knowledge assessment is established by the operating organisation.

The protocol number and the results of knowledge checks are recorded in the certificates of competence signed by the commission chairman.

The formats of certificates shall be defined by the operating organization.

258. Regular assessment of the personnel knowledge shall be performed in accordance with the procedure established in the operating organization:

1) for the pipeline maintenance personnel - at least once per 12 months;

2) for the management personnel and other specialists engaged in pipeline operation (including pipeline design, manufacturing, installation and testing) - at least once per three years.

Unscheduled checks of knowledge shall be performed in the following cases:

1) on transfer of the employee from one organization to another;

1) employee's off-the-job period exceeding 6 months;

3) upon the decision of the operating organization administration or upon request of the surveillance (control) person;

4) in case of pipeline accident.

In case of any amendments to the pipeline operation manual the operating personnel shall be familiarized with these amendments and sign the acknowledgment registration sheets.

In case of off-the-job period exceeding six months the pipeline maintenance personnel shall pass practical training in order to recover practical skills prior to knowledge check.

259. Admittance of the personnel to unsupervised maintenance of pipelines shall be arranged through the order of the operating organization.

260. The operating organization shall develop and approve a pipeline operation manual. In case of pipelines that are part of the process systems, the operation manual shall be developed for the system as a whole, taking into account the requirements of these Rules. The manual shall be available at the operating personnel workplaces and the operating personnel shall be familiarized with it with signed acknowledgment.

Technological schemes of pipelines and equipment shall be available at the workplaces.

261. In order to prevent accidents on steam pipelines operating at temperatures causing metal creep, the operating organization shall systematically monitor the increase of residual information. This requirement applies to steam pipelines made of carbon and molybdenum steels operating at a steam temperature of 450 °C and above, pipelines made of chromium-molybdenum and chromium-molybdenum-vanadium steels operating at a steam temperature of 500 °C and above and pipelines made of high-alloyed heat-resistant steels operating at a steam temperature of 550 °C and above.

Inspection, control measurements and cutting samples shall be performed based on an instruction approved by the operating organization.

262. The AEUF shall develop and implement a program for in-service pipeline metal inspection during operation.

Extension of the specified lifetime of pipelines

263. The specified pipeline lifetime may be extended based on a substantiated decision of the operating organization approved by the design organization, leading material science organization and a specialized organization employed for substantiation of the possibility of further pipeline operation.

Technical examination results for the pipeline (including technical diagnostics results), the remaining lifetime assessment, reliability and strength calculations confirming the possibility to extend the specified pipeline lifetime as well as any reports confirming the possibility for the pipeline to perform its functions within the extended service life in compliance with all safety requirements, metal condition inspection reports and in-service metal inspection programs developed for the additional lifetime shall be attached to this resolution.

VII. Pipeline painting and inscriptions

264. Depending on the pipeline purpose and medium parameters, the surface of the pipeline shall be painted in respective color and be marked.

Color, legend, size of letters and location of inscriptions shall comply with Appendix No. 7 hereto.

265. The number of inscriptions on one and the same pipeline is not regulated. The inscriptions shall be seen from the places of valve and gate control. Inscriptions are mandatory in places where the pipeline enters or exits the room.

266. In case the pipeline isolation surface is covered with metal sheathing (aluminum, galvanized iron sheets or other corrosion-resistant metals) sheathing painting is not mandatory. In this case, depending on the transported medium, appropriate designations shall be made.

267. Valves, gates and their drives shall be marked with the following:

1) the number and a reference designation of the shutoff or regulating device corresponding to the operational diagrams and instructions;

2) indication of the direction of rotation to the closing side (З) and the opening side (O).

268. The valves and drives shall be marked in the following places:

1) if the hand wheel is located close to the valve (gate) body - on the valve (gate) isolation body or on an attached plate;

2) in case of remote control using a hand wheel - on the hand wheel holder or bracket;

3) in case of remote control using a chain - on a plate fixedly connected to the chain wheel bracket and fixed in a position ensuring the best visibility from the control platform;

4) in case of remote control of a valve or a gate located under the control platform floor using a removable hand wheel (the shaft end is embedded in the floor and topped with a cover) - on the internal and external sides of the cover;

5) in case of remote control using an electric drive - near the starting switch.

In case of remote control, inscriptions shall be made on the controlled valve flywheels.

It is appropriate to use labeling plates located directly on the valves.

269. After registration, each pipeline shall be equipped with special plates of the size not less than 400 x 300 mm with the following information:

1) pipeline registration number;

2) permitted medium pressure;

3) permitted medium temperature;

4) date (month and year) of the next technical examination.

Each pipeline shall be equipped with at least three plates which shall be located at the ends of the pipeline and in the middle of it. If one and the same pipeline is located in several rooms, there shall be a plate in each room.

Appendix 1

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

TERMS AND DEFINITIONS

Inclusion is a generalized name for pores, slag and tungsten inclusions.

Cluster external outline is an outline limited by the outer edges of cluster inclusions and tangent lines connecting such edges.

A group of inclusions is a group consisting of two or several inclusions with the minimum distance between their edges less than the maximum width of at least one of the two adjacent inclusions under consideration; at the same time the external outline of the group of inclusions is limited by the outer edges of inclusions constituting the group and tangent lines connecting such edges; a group of inclusions is considered as one continuous inclusion for welded joint quality assessment.

A singular inclusion is an inclusion with the minimum distance from its edge to the edge of any adjacent inclusion not less than a triple maximum width of each of the two inclusions, but not less than a triple maximum inclusion size of the smaller one (of the two inclusions under consideration).

A singular cluster is a cluster with the minimum distance from its external outline to the external outline of any adjacent cluster or inclusion not less than a triple maximum width of the two clusters under consideration (or a cluster and an inclusion), but not less than a triple maximum cluster (inclusion) size of the smaller one (of the two elements under consideration).

A cluster is two or several inclusions with the minimum distance between their edges less than the distance specified for singular inclusions, but not less than the maximum width of any two adjacent inclusions under consideration.

The total reduced area of inclusions and clusters is the sum of reduced areas of singular inclusions and clusters.

Appendix 2

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

TYPES OF SAME-TYPE AND REFERENCE WELDED JOINTS

Similar weld joints are a group of weld joints with the following common characteristics:

1) welding technique;

2) grade (combination of grades) of the basic metal; weld joints between the parts made of different steel grades requiring application of welding materials of the same grades (combinations of grades) in accordance with the technical process may be united into the same group;

3) grade (combination of grades) of the welding material; weld joints performed with the use of different welding materials of the grades (combinations of grades) that may be used to weld parts made of the same steel may be united into the same group; electrodes shall have the same coating type (basic, rutile, cellulose, acid);

4) nominal thickness of welded parts at the welding zone; joints with the nominal thickness of parts at the welding zone within one of the following ranges may be united into the same group <*>:

--------------------------------

<*> For corner, T-shaped and overlapping joints the above-mentioned ranges shall be applied to weld-on parts; thickness of the basic parts may be disregarded.

up to 3 mm inclusive;

exceeding 3 mm and up to 10 mm inclusive;

exceeding 10 mm and up to 50 mm inclusive;

exceeding 50 mm;

5) curvature radius of the parts at the welding zone; weld joints between the parts with the curvature radius at the welding zone within one of the following ranges (for pipes - with half of the nominal outer diameter) may be united into the same group <**>:

--------------------------------

<**> For corner, T-shaped and overlapping joints the above-mentioned ranges shall be applied to weld-on parts; curvature radii of the basic parts may be disregarded.

up to 12,5 mm inclusive;

exceeding 12.5 mm and up to 50 mm inclusive;

exceeding 50 mm and up to 250 mm inclusive;

exceeding 250 mm;

6) type of weld joint (butt, corner, T-shaped, overlapping); corner, T-shaped and overlapping joints may be united into the same group;

7) edge preparation type; weld joints with one of the following types of edge preparation may be united into the same group:

with single-side edge preparation and the beveling angle exceeding 8°;

with single-side edge preparation and the beveling angle of up to 8° inclusive (narrow beveling);

with double-side edge preparation;

without any edge preparation;

8) root layer welding technique: on permanent backing (backing ring), on melted backing, without any backing (free temper bead formation), with weld root back run;

9) thermal regime of welding: with preliminary and concurrent heating, without any heating, with layer-by-layer cooling;

10) weld joint heat treatment regime.

Reference weld joint shall be identical to the controlled manufacturing weld joints (with regard to steel grades, sheet thickness or pipe size, edge preparation form, welding technique, welding materials, position of the weld joint, heating regimes and temperature, heat treatment) and performed by the same welding operator and with the same welding equipment at the same time with the controlled manufacturing weld joint.

Appendix 3

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

WELDED JOINT QUALITY ASSESSMENT STANDARDS

1. General

1.1. These quality assessment standards for weld joints establish the requirements for assessment of the quality of welded joints operated under pressure and performed using arc, electroslag, electron-beam and gas welding during visual, measuring, penetration, magnetic particle, radiographic and ultrasonic control as well as during mechanical and metallographic testing.

Quality assessment standards for weld joints during manufacturing and installation of AEUF pipelines shall be developed based on the requirements and instructions of these standards and shall be specified in the DD for welded joints control.

In case of welded joints made using other types of welding, non-pressurized welded joints, as well as for welded joint quality control using other methods, quality assessment standards for weld joints for manufacturing and installation of pipelines shall be established in the DD.

1.2. Welded joint quality assessment standards  shall be taken in accordance with the following dimensional values (DV) of welded joints:

1) based on the rated thickness of welded parts - for butt weld joints between parts with similar thickness (in case of pretreatment of part ends by means of boring, flaring, calibration or crimping - based on the nominal thickness of welded parts in the treatment area);

2) based on the rated thickness of a thinner part - for butt weld joints with different rated thickness (in case of pretreatment of the end of the thinner part - based on its rated thickness in the treatment area);

3) based on the rated height of the angular weld - for angle, T-shaped and overlapping weld joints (for angle and T-shaped weld joints with complete fusion the rated thickness of the thinner part can be accepted as the dimensional value);

4) based on the double rated thickness of a thinner part (of the two welded parts) - for edge weld joints (except for welding of tubes into tube plates);

5) based on the rated thickness of pipe walls - for welding of tubes into tube plates.

In case of radiographic control of weld joints through two walls, the quality assessment standards shall be taken according to the same dimensional value as in case of control through one wall, based on the rated thickness of one wall.

1.3. The extension (length, perimeter) of welded joints is defined based on the external surface of welded parts near the weld edges (in case of connections of pipe sleeves, angular and T-shape connections - based on the external surface of the welded-on part near the edge of the angular weld).

1.4. The number and the reduced area of singular inclusions and clusters identified by means of the used non-destructive testing methods shall not exceed the values specified in these standards on any welded joint section with the length of 100 mm.

For welded joints with the length of less than 100 mm, the values of number and the reduced area of singular inclusions and clusters shall be reduced proportionally to the decrease of the length of joint under examination. If a fractional value is received, it shall be rounded to the nearest integer value.

2. Visual and dimensional inspection

2.1. In case of visual and dimensional inspection of welded joints, the following defects shall not be accepted:

1) cracks of all types and directions;

2) incomplete fusion (faulty fusion) in the between the base metal and the weld, or between weld beads;

3) incomplete fusion in the weld root (except for cases specified in the RD);

4) rolls (collars) and metal splashes;

5) unfilled craters;

6) holes;

7) burns-through;

8) clusters;

9) undercuts (except for cases specified in the RD);

10) deviations of seam dimensions beyond the established limits.

2.2. The standards for acceptable flaws identified during visual and dimensional control are specified in Table No.1 of this Appendix.

Table 1

The standards for surface flaws in weld joints

3. Capillary control

3.1. In case of welded joint control by means of indicator trace, prolonged and non-singular indications are not accepted. The number of singular round indicator traces shall not exceed the standards established in Table No.1 of this Appendix for singular inclusions, and the largest dimension of each indicator trace shall not exceed the triple value of such standards.

3.2. The discontinuity flaws revealed during control in accordance with paragraph 3.1 of this Appendix can be assessed according to the actual values after removal of the reagent. For this purpose, one shall follow the requirements of paragraph 2.1 and Table No. 1 of this Appendix. The results of this assessment are not final.

4. Magnetic powder control

4.1. Quality assessment standards for magnetic powder control shall correspond to the standards for visual control (paragraph 2.1 and Table No. 1 of this Appendix).

4.2. The discontinuities revealed during control in accordance with paragraph 4.1 of this Appendix may be assessed in accordance with their actual size after removal of emulsion or powder. The results of this assessment are not final.

5. Radiographic control

5.1. The quality of welded joints shall be considered satisfactory if the radiographic shots do not reveal any cracks, incomplete fusion, burns-through, wormholes, inadmissible root convexity and concavity, and the size, number and total reduced area of singular inclusions and clusters do not exceed the limits specified in Table No.1 of this Appendix.

The required shot sensitivity level shall be established in the DD.

6. Ultrasonic control

6.1. The quality of welded joints shall be considered satisfactory if the following conditions are fulfilled:

1) the revealed discontinuities are not extended (the conditional discontinuity length shall not exceed the conditional length of the corresponding reference reflector);

2) the distance along the scanning surface between two adjacent discontinuities shall be no less than the conditional length of the larger discontinuity (in case of singular discontinuities);

3) the equivalent area and the number of singular discontinuities in case of AEUF pipelines control shall not exceed the limits specified in the RD.

7. Mechanical testing

7.1. The quality of welded joints shall be considered satisfactory based on results of mechanical tests if the following conditions are fulfilled:

1) the ultimate tensile strength shall be not less than the minimum permissible value for base metal, and in case of testing welded joints of parts with different standard tensile strength values, this value shall be not less than the minimum permissible value for the less strong base metal;

2) the bending angle in case of static bend test and the gap between compressed surfaces at collapsing testing of butt joints of pipes with the outer diameter of less than 108 mm and wall thickness less than 12 mm shall comply with the requirements specified in Table No. 2 of this Appendix;

3) the impact viscosity in case of impact bending tests of samples of type VI according to state standard with incision along the weld shall be not less than:

49 J/sm² (5 kgf · m/cm²) - for welded joints between the components made of pearlitic steel with components made of high alloy steels of martensite-ferrite class;

69 J/sm² (7 kgf · m/cm²) - for welded joints between the components made of chromium-nickel steels of austenitic class.

Table 2

Requirements to the results of

bending and collapsing tests

--------------------------------

<*> The values of the bending angle for gas welded joints are specified in brackets.

8. Metallographic analysis

The quality assessment standards for welding joints as a result of metallographic analysis shall comply with the RD requirements.

Appendix 4

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

REQUIREMENTS FOR THE PIPELINE CERTIFICATE CONTENT

The pipeline certificate shall include the following information (in the scope to be defined by the manufacturing organization depending on the pipeline type).

name and address of the manufacturing organization;

purpose;

manufacturing (production) date;

medium;

medium working parameters; pressure, MPa, temperature, °C;

specified service life;

design lifetime;

design number of start-ups;

plans, drawings, test protocols, acceptance certificates and other documents for pipeline manufacturing (production) and installation.

Appendix 5

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

MATERIALS

USED FOR MANUFACTURE OF PRESSURIZED STEAM AND HOT

WATER PIPELINES

Table 1

Sheet steel

Table 2

Seamless pipes

Table No. 3

Welded pipes

Table No. 4

Steel forged parts

Table No. 5

Cast steel

Table No. 6

Fastening hardware

Table No. 7

Iron castings

Appendix 6

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

ASSIGNMENT OF MATERIALS TO TYPES AND CLASSES

--------------------------------

<*> Materials are not subject to welding (fastening parts).

Appendix 7

to federal rules and regulations

in the field of nuclear energy use

"Regulations for design and safe

operation of steam

and hot water pipelines for

nuclear facilities",

approved by Order of the Federal

Environmental,

Industrial and Nuclear Supervision Service

dated 2 March 2018 No. 94

PIPELINE PAINTING AND INSCRIPTIONS

1. Identification painting and numerical designation of enlarged pipelines groups shall comply with the requirements of Table No.1 of this Appendix.

Table 1

2. Pipelines identification painting shall be performed continuously along the whole surface of communication lines or in separate sections.

The method for identification painting shall be determined based on the location of pipelines, their length, diameter, number of lines laid together, industrial safety and hygiene requirements, the lighting and visibility of pipelines for maintenance personnel and general architectural solution.

Sectional pipeline painting is performed in shops with a large number or a significant length of pipelines, and in case that according to the working conditions it is undesirable to use numerous bright colors due to increased requirements to color rendition or the nature of the interior architectural solution.

3. In case of application of identifying painting on pipelines located inside production premises, the other surface of communication lines shall be painted the same color as the walls, partitions, ceilings and other interior components which constitute the background for the pipelines. When doing so, it is unacceptable to paint pipelines between the section with an indication color used for designation of other larger substance groups.

4. In case of application of sectional indication painting on pipelines located outside, the other communication line surface shall be painted in the colors decreasing the thermal influence of the solar radiation on the pipelines.

5. In case of laying communication lines in non-passable channels and in case of non-channel laying, sections of indication painting shall be applied on pipelines within the area of chambers and inspection wells.

6. Sections of indication painting shall be applied taking into account the local conditions in the most important communication line parts with an interval of not more than 10 m inside production rooms and on external installations, and not more than 30 - 60 m on external manifold lines.

7. The width of identification painting sections shall be taken in accordance with the pipeline's external diameter (taking into account the insulation):

for pipes with the diameter of less than 300 mm - not less than four diameters;

for pipes with the diameter of more than 300 mm - not less than two diameters.

In case of a larger number of pipelines laid parallel to each other, indication painting sections on all pipelines shall have the same width and be applied at equal intervals.

In case of larger pipeline diameters, it is allowed to apply indication painting sections in the form of lines with a height of at least 1/4 of the pipeline circumference.

The width of lines shall correspond to the dimensions specified for the pipelines of this diameter.

8. In order to designate the most hazardous substances transported in pipelines, it is necessary to paint colored warning rings.

The colors of identification painting of warning rings shall correspond to the ones specified in Table No.2 of this Appendix.

Table 2

Notes.

1. In case of application of yellow rings for indication painting of gas and acid pipelines, the rings shall have black edges with a width of at least 10 mm.

2. In case of application of green rings for indication painting of water pipelines, the rings shall have white edges with a width of at least 10 mm.

9. In accordance with their danger to the life and health of people or the operation of facility, substances transported in pipelines shall be divided into three groups designated with the corresponding number of warning rings in accordance with Table No. 3 of this Appendix.

Table No. 3

10. The width of warning rings and the distance between them shall be taken based on the outer diameter of pipelines in accordance with Figure 1 and Table No. 4 of this Appendix.

Figure 1. The width of warning rings and the distance

between them

Table No. 4

11. In case of over five pipelines laid parallel to each other, warning rings on all pipelines shall have the same width and be applied at equal intervals.

12. In order to mark pipelines carrying substances which are extremely hazardous to the life and health of people or the operation of facility, and in case it is necessary to specify the type of hazard, warning signs shall be applied in addition to the colored warning rings.

13. The following substances shall be designated with warning signs: toxic, combustible and explosive substances, and other hazardous substances transported in pipelines.

14. Warning signs shall have a triangular shape. The warning symbols shall be painted black against a yellow background.

15. The warning sign images shall correspond to the ones shown in Table No. 5 and Figure 2 of this Appendix.

Table No. 5

Figure 2. Images of warning signs

16. It is allowed to mark the substances by numbers in accordance with Table No. 6 of this Appendix.

Table No. 6