Safety requirements for pipelines. Rules for the construction and safe operation of technological pipelines
Industrial systems for transportation through pipes of various substances can be dangerous, therefore, they require high-quality, qualified service. In this article, we will explain the rules for the construction and safe operation of process pipelines, which have undergone significant changes in recent years.
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Status for 2019 of the Decree of the Federal Mining and Industrial Supervision of Russia dated May 10, 2003 No. 80 "On Approval of the Rules for the Arrangement and Safe Operation of Process Pipelines"
Before talking about this document, let us recall what exactly is referred to as process pipelines (TP). These are complex devices for moving various substances (water, fuel, reagents, steam, raw materials, semi-finished products, finished products), which are used at industrial facilities and are necessary to ensure technological processes during equipment operation.
Another important normative act adopted on December 27, 2012 "On the Approval of the Safety Guide "Recommendations for the Construction and Safe Operation of Process Pipelines"" became a guideline for the use and maintenance of HPs.
To date, the last two documents define the basic rules for the operation of HP for industrial use.
Rules for the operation of pipelines
The current PB "Technological pipelines" impose strict requirements for the use, maintenance, revision of technological pipeline systems, as well as for the qualifications of specialists working with them. We will discuss these requirements in more detail below.
Operating procedure
First of all, it is necessary to check the performance of the systems at regular intervals. It's about about the external examination to check technical condition pipes or connections, inspection of areas subject to vibration with special devices, as well as the elimination of any problems found.
Every month, you need to examine the following areas of the TT with special predilection:
- flange connections;
- insulation, coating;
- drainage systems,
- support fasteners.
If leaks are detected, it is necessary to reduce the working pressure to atmospheric, and reduce the temperature (on heating lines) to 60ºС. Only after that .
Order No. 116 mentioned above prohibits the use of technological CT in the following situations:
- malfunction or complete inoperability of the system;
- inconsistency ;
- the presence of defects that may affect the safety of work;
- malfunction of fittings, instrumentation, safety, blocking devices, protective equipment, alarms;
- expiration of the service life specified in the passport of the equipment.
When using TT at hazardous production facilities, special attention should be paid to personnel issues. To work with technological systems transportation, responsible specialists should be involved, as well as a sufficient number of qualified workers. All of them should production instructions and labor protection requirements.
Long before the start-up of the system, it is necessary to approve the industrial safety instructions at the enterprise, as well as separately instructions for all responsible specialists and workers.
Requirements for qualifications, duties of employees
The safety of technological pipelines can only be ensured by workers with sufficient qualifications. They must be at least 18 years of age and have vocational education(in the case of specialists) or relevant vocational training (for workers). Before being allowed to work, which will be issued by a separate order, they must go through the following procedures:
- verification of knowledge of the requirements of safe work.
At least once every 12 months, employees must undergo short-term training with a knowledge test, followed by an internship. On the requirements for welders, welding production specialists who are engaged in the repair, installation, reconstruction, modernization of technological pipeline systems,
Now let's talk about the responsibilities of employees. Employees who are involved in the operation of the TT are required to:
- understand all the performance criteria of the CT;
- to control technical processes;
- in case of accidents, incidents, be able to act strictly according to the instructions;
- in the event of any emergency or threat of its occurrence, suspend the operation of the system, informing your manager about it.
If damage, violations of safe operation conditions, deviations from technology or unacceptable changes in the parameters of the system operation were detected, it is necessary to stop all work, or not start it at all.
List official duties for responsible specialists it will be noticeably wider. You will need at least two of these employees with a technical professional background certified in industrial safety.
The specialist who is responsible for must:
- inspect the TT, check the mode of its operation;
- to control the preparation of TT for examination, to conduct all the necessary document flow;
- issue instructions in case of violations in work;
- monitor compliance with industrial safety rules, own instructions or orders government agencies, as well as repair, reconstruction of the system;
- take part in surveys, examinations;
- supervise emergency response drills;
- upon detection of violating employees, demand their removal from work and sending them to an extraordinary knowledge test.
The second employee is a specialist responsible for safe operation. His responsibilities include:
- ensuring operability, repair, preparation of HP for technical examination, diagnostics;
- monitoring compliance by workers;
- holding and participating in periodic inspections, technical examinations of the system;
- storage of all technical documentation TT (technical passport, instructions for installation, use, manuals), checking entries in the shift log;
- conducting counter-emergency training of employees;
- implementation of all instructions to eliminate the identified violations;
- keeping records of CT load cycles if they are operated in a cyclic mode.
Approved
by order of the Minister for emergencies Republic of Kazakhstan
Industrial safety requirements for
operation of technological pipelines
Chapter 1. General provisions
1. These Requirements apply to designed, newly manufactured and modernized steel technological pipelines intended for the transportation of gaseous, vaporous and liquid media in the range from a residual pressure (vacuum) of 0.001 MPa (0.01 kgf / cm) to a nominal pressure of 320 MPa (3200 kgf/cm) and operating temperatures from -196 ° C to 700 ° C and operated at hazardous production facilities.
2. The wall thickness of pipes and pipeline parts is determined by strength calculation depending on the design parameters, corrosion and erosion properties of the medium according to regulatory and technical documents in relation to the current range of pipes. When choosing the wall thickness of pipes and pipeline parts, the features of their manufacturing technology (bending, assembly, welding) are taken into account.
For the design pressure in the pipeline are taken:
1) design pressure for the apparatus to which the pipeline is connected;
2) for pressure pipelines (after pumps, compressors, gas blowers) - the maximum pressure developed by a centrifugal machine with a closed valve on the discharge side; and for reciprocating machines - the response pressure of the safety valve installed on the pressure source;
3) for pipelines with safety valves installed on them - the pressure setting of the safety valve.
Pipelines that are tested for strength and density together with the apparatus are designed for strength taking into account the test pressure of the apparatus.3. When calculating the thickness of the walls of pipelines, the allowance for compensation of corrosive wear to the calculated wall thickness should be selected based on the condition for ensuring the required design service life of the pipeline and the corrosion rate.
Depending on the corrosion rate of steels, the media are divided into:
1) non-aggressive and low-aggressive - with a corrosion rate of up to 0.1 mm / year (resistant steel);
2) medium aggressive - with a corrosion rate of 0.1-0.5 mm/year;
3) highly aggressive - with a corrosion rate of over 0.5 mm/year.
At a corrosion rate of 0.1-0.5 mm/year and more than 0.5 mm/year, steel is considered low-resistant.
4. When choosing materials and products for pipelines, consider:
1) design pressure and design temperature of the transported medium;
2) properties of the transported medium (aggressiveness, explosion and fire hazard, harmfulness, etc.);
3) properties of materials and products (strength, cold resistance, corrosion resistance, weldability, etc.);
4) negative ambient temperature for pipelines located on outdoors or in unheated areas. For the calculated, negative air temperature when choosing materials and products for pipelines, one should take:
the average temperature of the coldest five-day period of the region with a probability of 0.92, if working temperature walls of the pipeline under pressure or vacuum, positive;
the absolute minimum temperature of the given area, if the operating temperature of the pipeline wall, under pressure or vacuum, becomes negative due to the influence of ambient air.
5. For pipelines and fittings design organization service life is set to project documentation.
Chapter 2. Process pipelines with conditional pressure
up to 10 MPa (100 kgf/cm)
Paragraph 1. Classification of pipelines
6. Pipelines with pressure up to 10 MPa (100 kgf/cm) inclusive, depending on the hazard class of the transported substance (explosion, fire and harmfulness) are divided into groups A, B, C and depending on the operating parameters of the medium (pressure and temperature) - into five categories (I, II, III, IV, V).
The classification of pipelines is given in Appendix 1 of these Requirements.
8. The hazard class of technological media is determined by the project developer based on the hazard classes of substances contained in the technological environment and their ratios.
10. It is allowed, depending on the operating conditions, to take a higher (than determined by the operating parameters of the environment) category of pipelines.
The designation of the group of a certain transported medium includes the designation of the medium group (A, B, C) and the designation of the subgroup (a, b, c), reflecting the hazard class of the substance.
Piping group designation in general view corresponds to the designation of the transported medium group. The designation "pipeline of group A(b)" means a pipeline through which a medium of group A(b) is transported.
The group of a pipeline transporting media consisting of various components is established according to the component that requires the pipeline to be assigned to a more responsible group. If the mixture contains hazardous substances of hazard classes 1, 2 and 3 and if the concentration of one of them is the most dangerous, the group of the mixture is determined by this substance.
If the most dangerous physical and chemical properties the component is included in the composition of the mixture in an insignificant amount, the issue of assigning the pipeline to a less responsible group or category is decided by the design organization.
For vacuum pipelines, it is not the nominal pressure that is taken into account, but the absolute working pressure.
Pipelines transporting substances with an operating temperature equal to or higher than their auto-ignition temperature or an operating temperature below -40 ° C, as well as those incompatible with water or atmospheric oxygen when normal conditions belong to category I.
Paragraph 2. Requirements for materials used for pipelines
11. Pipes, fittings, flanges, gaskets and fasteners used for pipelines comply with the relevant regulatory and technical documentation in terms of quality, technical characteristics and materials.
Quality and technical specifications materials and finished products used for the manufacture of pipelines, is confirmed by the manufacturer's certificates. Materials and products that do not have certificates may only be used for pipelines of categories II and below and after they have been checked and tested in accordance with the regulatory and technical documentation.
The material of the pipeline parts corresponds to the material of the pipes to be connected. When using dissimilar pipes and their welding, they are guided by the instructions of the relevant regulatory and technical documents.
12. Pipes and shaped parts of pipelines are made of steel with technological weldability, with a ratio of yield strength to tensile strength of not more than 0.75, relative elongation of the metal at break on five-fold samples of at least 16% and impact strength of at least 30 J/cm ( 3.0 kgf m/cm) at the minimum design temperature of the pipe element wall.
13. Pipes, depending on the parameters of the transported medium, are selected in accordance with the regulatory and technical documentation.
14. Seamless pipes made from an ingot, fittings for these pipes are allowed to be used for pipelines of groups A and B of the first and second categories, provided that they are controlled by ultrasonic flaw detection (hereinafter referred to as ultrasonic testing) in a volume of 100% over the entire surface.
15. For pipelines transporting liquefied hydrocarbon gases (hereinafter referred to as LPG), as well as substances belonging to group A (a), seamless hot and cold formed pipes should be used. In accordance with the instructions of the normative and technical documentation, the use of electrical welded pipes with a nominal diameter of more than 400 mm for pipelines transporting substances belonging to group A (a) and liquefied hydrocarbon gases at a metal corrosion rate of up to 0.1 mm / year, with an operating pressure of up to 2.5 MPa (25 kgf / cm ) and a temperature up to 200°C, heat-treated, 100% control of welds (by ultrasonic testing or transillumination) with positive results of mechanical tests of specimens from welded joints in full, including impact strength.
It is allowed to use shells made of sheet steel as tubes in accordance with the requirements for the design and safe operation of pressure vessels for nominal pressure up to 2.5 MPa (25 kgf/cm).
16. For pipelines, pipes with normalized chemical composition and mechanical properties of the metal (group B) are used.
17. The pipes are tested by the manufacturer with a test hydraulic pressure specified in the normative and technical documentation for pipes, or have an indication in the certificate of the guaranteed value of the test pressure.
It is allowed not to carry out hydrotesting of seamless pipes if they were subjected to control over the entire surface non-destructive methods.
18. Electric-welded pipes with a spiral seam may only be used for straight sections of pipelines.
19. Electric-welded pipes used for the transportation of substances of groups A (b), B (a), B (b) (Appendix 1), with the exception of liquefied gases with a pressure of more than 1.6 MPa (16 kgf / cm) and groups B (c ) and B at a pressure of more than 2.5 MPa (25 kgf/cm), with a working temperature of more than 300 ° C in a heat-treated state, and their welds are subjected to 100% non-destructive testing (ultrasound or radiography) and a bend or impact test.
It is allowed to use non-heat-treated pipes with a ratio of the outer diameter of the pipe to the wall thickness equal to or more than 50 for the transportation of media that do not cause corrosion cracking of the metal.
20. Electric-welded pipes in contact with a medium that causes corrosion cracking of the metal, regardless of pressure and wall thickness in the heat-treated state, and their welds are of equal strength to the base metal and are subjected to 100% control by non-destructive methods (ultrasound or radiography).
21. Pipes made of carbon semi-calm steel may be used for group B environments with a wall thickness of not more than 12 mm in areas with a design outdoor temperature of at least -30 ° C, while ensuring that the temperature of the pipeline wall during operation is not lower than -20 ° C.
Pipes made of carbon boiling steel are allowed to be used for group B media with a wall thickness of not more than 8 mm and a pressure of not more than 1.6 MPa (16 kgf / cm) in areas with an estimated air temperature of at least -10 ° C.
22. The design of flanges and materials for them should be selected taking into account the parameters of the working media according to the normative and technical documentation.
23. Flat welded flanges are used for pipelines operating at a nominal pressure of not more than 2.5 MPa (25 kgf / cm) and an ambient temperature of not more than 300 ° C. For pipelines of groups A and B with nominal pressure up to 1 MPa (10 kgf/cm), flanges are used, provided for a nominal pressure of 1.6 MPa (16 kgf/cm).
24. For pipelines operating at a conditional pressure of more than 2.5 MPa (25 kgf / cm), regardless of temperature, as well as for pipelines with an operating temperature above 300 ° C, regardless of pressure, butt-welded flanges are used.
25. Butt-weld flanges are made from forgings or shroud blanks.
It is allowed to manufacture butt-welded flanges by rolling blanks along the plane of the sheet for pipelines operating at a nominal pressure of not more than 2.5 MPa (25 kgf / cm), or bending forged strips for pipelines operating at a nominal pressure of not more than 6.3 MPa (63 kgf / cm), subject to 100% control of welds by radiographic or ultrasonic methods.
26. When choosing the type of sealing surface of the flanges, be guided by Appendix 2 of these Requirements.
27. For pipelines transporting substances of groups A and B of technological facilities of the 1st category of explosion, it is not allowed to use flange connections with a smooth sealing surface, except for the cases of using spirally wound gaskets with a restrictive ring.
28. Fasteners for flange connections and materials for them should be selected depending on the operating conditions and steel grades of the flanges.
To connect flanges at temperatures above 300°C and below -40°C, regardless of pressure, use studs.
29. In the manufacture of studs, bolts and nuts, the hardness of studs or bolts is higher than the hardness of nuts by at least 10 - 15 HB.
30. It is not allowed to manufacture fasteners from boiling, semi-calm, Bessemer and automatic steels.
31. The material of blanks or finished fasteners made of high-quality carbon, heat-resistant and heat-resistant alloy steels are heat-treated.
For fasteners used at pressures up to 1.6 MPa (16 kgf / cm) and operating temperatures up to 200 ° C, fasteners made of carbon steel with threads up to 48 mm in diameter may not be heat treated.
32. In the case of using fasteners made of austenitic steels at a working temperature of the medium above 500 ° C, it is not allowed to produce a thread by knurling.
33. The materials of fasteners should be selected with a coefficient of linear expansion close in value to the coefficient of linear expansion of the flange material with a difference in the values of the coefficients of linear expansion of materials not exceeding 10%.
It is allowed to use materials of fasteners and flanges with coefficients of linear expansion, the values of which differ by more than 10%, in cases justified by strength calculations or experimental studies, for flange connections at an operating temperature of the medium of not more than 100 ° C.
34. Gaskets and gasket materials for sealing flange connections are selected depending on the transported medium and its operating parameters in accordance with the project, regulatory and technical documentation.
35. Fittings of pipelines, depending on the parameters of the transported medium and operating conditions, should be selected according to the normative and technical documentation.
36. Shaped parts of pipelines should be made of steel seamless and longitudinally welded pipes or sheet metal, the metal of which meets the requirements of the project, regulatory and technical documentation, the conditions of weldability with the material of the connected pipes.
37. Parts of pipelines for environments that cause corrosion cracking of metal, regardless of design, steel grade and manufacturing technology, are subject to heat treatment.
Local heat treatment of welded joints of sectional bends and welded tees from pipes is allowed if heat-treated pipes are used for their manufacture.
38. When choosing welded parts of pipelines, depending on the aggressiveness of the medium, temperature and pressure, be guided by regulatory and technical documentation.
39. Welding fittings and quality control welded joints produce in accordance with the requirements of normative-technical and project documentation.
40. A branch from the pipeline is carried out by one of the methods set out in Appendix 3 of these Requirements. Reinforcement of tee connections with stiffeners is not allowed.
41. Connection of branches according to method "a" (Appendix 3) is used in cases where the weakening of the main pipeline is compensated by the available safety margins of the connection.
42. When choosing a method for connecting branches to the main pipeline, give preference to methods "b", "c", "e" (Appendix 3).
43. An overlay on a branch pipeline (connection according to method "e" in Appendix 3) is installed with a ratio of the diameters of the branch and main pipelines of at least 0.5.
44. Welded tees are used at pressure P y - up to 10 MPa (100 kgf / cm).
45. Welded elbows with nominal bore D y = 150÷400 mm should be used for process pipelines at pressure P y not more than 6.3 MPa (63 kgf/cm).
Welded elbows with nominal bore D y =500÷1400 mm may be used for process pipelines at pressure P y not more than 2.5 MPa (25 kgf/cm2).
46. Welded concentric and eccentric transitions with a conditional passage D y \u003d 250 ÷ 400 mm can be used for process pipelines at pressure P y up to 4 MPa (40 kgf / cm), and with D y 500 ÷ 1400 mm - at P y up to 2 .5 MPa (25 kgf/cm).
The limits of the use of steel transitions, depending on the temperature and aggressiveness of the medium, correspond to the limits of the use of connected pipes for similar steel grades.
Welded joints of transitions are subject to 100% control by ultrasonic or radiographic method.
47. It is allowed to use petal transitions for technological pipelines with nominal pressure Р y not more than 1.6 MPa (16 kgf/cm) and nominal diameter D y =100÷500 mm.
It is not allowed to install petal transitions on pipelines intended for the transportation of liquefied gases and substances of group A (a) (Appendix 1).
48. Flap transitions to be welded with subsequent 100% control of welds by ultrasonic or radiographic method.
After manufacturing, the petal transitions should be subjected to high-temperature tempering.
49. Welded crosses are allowed to be used on pipelines made of carbon steels at an operating temperature not exceeding 250 ° C.
Crosses made of electric-welded pipes are allowed to be used at a pressure P y of not more than 1.6 MPa (16 kgf / cm 2), while they are made of pipes recommended for use at a pressure P y of at least 2.5 MPa (25 kgf / cm 2 ).
Crosses made of seamless pipes are allowed to be used at a pressure P y of not more than 2.5 MPa (25 kgf / cm 2), provided that they are made from pipes recommended for use at a pressure P y of at least 4 MPa (40 kgf / cm 2).
50. For technological pipelines, use steeply curved bends made of seamless and welded straight-seam pipes by hot stamping or broaching, bent and stamp-welded bends.
51. Bent bends made of seamless pipes are used instead of sharply bent and welded bends in cases where it is required to minimize the hydraulic resistance of the pipeline, on pipelines with a pulsating medium flow (to reduce vibration), on pipelines with a nominal diameter D y less than 25 mm.
The limits of application of smooth-bent bends with a bending radius R≥2D n from pipes of the current assortment correspond to the limits of the use of pipes from which they are made.
52. When choosing the bending radius of smooth-bent bends, be guided by the design and normative and technical documentation.
The minimum length of the straight section from the end of the pipe to the beginning of the rounding is taken equal to the diameter D n of the pipe, but not less than 100 mm.
54. The temperature limits for the use of materials for flange plugs or plugs installed between flanges should be taken taking into account the temperature limits for the use of flange materials.
55. Quick-release plugs are produced and installed in accordance with the project.
Welded, flat and ribbed plugs are allowed to be used for technological pipelines transporting substances of groups A and B at pressure P up to 2.5 MPa (25 kgf / cm 2).
56. Plugs installed between flanges, quick-release plugs should not be used to separate two pipelines with different media, the mixing of which is unacceptable.
57. The quality and material of the plugs are confirmed by a certificate.
On each removable plug (on the shank, and in its absence - on the cylindrical surface) indicate the number of the plug, steel grade, nominal pressure P y and nominal bore D y.
58. The installation and removal of plugs is noted in the log.
Chapter 3. High pressure process pipelines
over 10 MPa (100 kgf / cm 2) up to 320 MPa (3200 kgf / cm 2)
Paragraph 1. General provisions
59. The design of the pipeline ensures safety during operation and provides for the possibility of its complete emptying, cleaning, flushing, purging, external and internal inspection, control and repair, removal of air from it during a hydraulic test and water after it.
60. If the design of the pipeline does not allow for external and internal inspections, control or testing, the project indicates the methodology, frequency and scope of control and repair, the implementation of which will ensure the timely detection and elimination of defects.
61. Connections of pipeline elements operating under pressure up to 35 MPa (350 kgf / cm 2) should be made by welding with butt, without backing ring, welded joints. Flange connections may be provided at the points of connection of pipelines to devices, fittings and other equipment having counter flanges, in sections of pipelines that require periodic disassembly or replacement during operation. Connections of pipelines under pressure over 35 MPa (350 kgf / cm 2) should be made in accordance with regulatory and technical documents for these conditions.
62. In pipelines intended for operation under pressure up to 35 MPa (350 kgf / cm 2), it is allowed to weld fittings in straight sections, use tees welded from pipes, stamp-welded elbows with two longitudinal seams, subject to 100% control of welded joints by non-destructive methods .
63. Welding of fittings into welds, into bent elements (in places of bends) of pipelines is not allowed.
On bends of pipelines operating under pressure up to 35 MPa (350 kgf / cm 2), it is allowed to weld one fitting (pipe) for a measuring device with an inner diameter of not more than 25 mm.
64. To connect elements of pipelines made of high-strength steels with a tensile strength of 650 MPa (6500 kgf / cm 2) or more, use threaded couplings or flange connections.
65. At the locations of the most stressed welded joints and measurement points of residual deformation accumulated during metal creep, provide removable insulation sections.
Paragraph 2. Requirements for the design of the pipeline
66. Parts of high-pressure pipelines shall be made from forgings, forgings and pipes. It is allowed to use other types of blanks if they ensure safe operation during the estimated service life, taking into account the specified operating conditions.
67. The ratio of the inner diameter of the branch to the inner diameter of the main pipe in forged tee-inserts is assumed to be at least 0.25. If the ratio of the diameter of the fitting and the diameter of the main pipe is less than 0.25, tees or fittings are used.
68. The design and geometric dimensions of tees welded from pipes, stamped rings, bent bends and fittings comply with the requirements of the project.
69. Tees welded from pipes, stamp-welded bends, tees and bends from billets cast using electroslag technology can be used for pressures up to 35 MPa (350 kgf / cm 2). In this case, all welds and metal of cast billets are subject to non-destructive testing in the amount of 100%.
70. The ratio of the inner diameter of the fitting (branch) to the inner diameter of the main pipe in welded tees is taken no higher than 0.7.
71. The use of bends welded from sectors is not recommended.
72. Bent branches after bending are subjected to heat treatment.
73. Elbows bent from steel grades 20, 15GS, 14KhGS, after cold bending, are subjected to tempering, provided that before cold bending, the pipes were quenched with tempering or normalized.
74. For detachable connections, use threaded flanges and butt-welded flanges, taking into account the requirements of paragraph 62 of these Requirements.
75. As sealing elements of flange connections, use metal gaskets-lenses of flat, octagonal, oval and other sections.
76. On parts of pipelines, threaded flanges, couplings and fasteners, a standard thread is made. The shape of the cavities of the external threads is rounded. Thread tolerances - 6H, 6 g. The quality of the thread is checked by the free passage of the thread gauge.
77. In the case of the manufacture of fasteners by cold deformation, they are subjected to heat treatment - tempering. Thread rolling on studs austenitic steel for operation at temperatures above 500°C is not allowed.
78. The design and location of welded joints ensure their high-quality performance and control by all the methods provided for in the process of manufacture, installation, operation and repair.
79. The distance between adjacent circumferential butt welded joints is not less than three times the nominal thickness of the welded elements, but not less than 50 mm with a wall thickness of up to 8 mm and not less than 100 mm with a wall thickness of more than 8 mm.
In any case, the specified distance provides the possibility of local heat treatment and seam inspection by non-destructive methods.
Welded joints of pipelines should be located from the edge of the support at a distance of at least 50 mm for pipes with a diameter of less than 50 mm and at least at a distance of 200 mm for pipes with a diameter of more than 50 mm.
80. The distance from the beginning of the pipe bend to the axis of the circumferential weld for pipes with an outer diameter of up to 100 mm is not less than the outer diameter of the pipe, but not less than 50 mm.
For pipes with an outer diameter of 100 mm or more, this distance is at least 100 mm.
Paragraph 3. Requirements for materials used for high pressure pipelines
81. For the manufacture, installation and repair of pipelines for pressures over 10 MPa (100 kgf / cm 2) up to 320 MPa (3200 kgf / cm 2) and temperatures from -50 to 540 ° C, use standard materials and semi-finished products.
82. The conditions for the use of materials for corrosive environments containing hydrogen, carbon monoxide, ammonia are determined in accordance with Appendix 4 of these Requirements.
83. The parameters for the use of steels indicated in Table 1 of Appendix 4 of these Requirements also apply to welded joints, provided that the content of alloying elements in the weld metal is not lower than in the base metal. Steel grades 15X5M and 15X5M-III according to Table 1 of Appendix 4 of these Requirements can be used up to 540 ° C at a partial hydrogen pressure of not more than 6.7 MPa (67 kgf / cm 2).
The application conditions in Table 2 of Appendix 4 of these Requirements are set for a carbonyl corrosion rate of not more than 0.5 mm/year.
The application conditions in Table 3 of Appendix 4 of these Requirements are set for a nitriding rate of not more than 0.5 mm/year.
84. The quality and properties of semi-finished products are confirmed by certificates and appropriate markings. In the absence or incompleteness of the certificate or marking, carry out all the necessary tests with the registration of their results in a protocol that supplements or replaces the certificate.
85. The manufacturer of semi-finished products controls the chemical composition of the material. Include in the certificate the results of chemical analysis obtained directly for the semi-finished product, or data on the certificate for the workpiece used for its manufacture.
86. Control mechanical properties metal of semi-finished products is carried out by tensile tests at 20 ° C, with the determination of the tensile strength, conditional or physical yield strength, relative elongation, relative narrowing in impact bending.
87. Test for impact bending are subjected to semi-finished products on samples with concentrators of type U (KCU) and type V (KV) at a temperature of 20 ° C, at negative temperatures in the case when the product is operated under these conditions.
Impact strength values at all test temperatures for KCU are not less than 30 J/cm2 (3.0 kgf m/cm), for KV - not less than 25 J/cm2 (2.5 kgf m/cm2).
88. The normalized values of mechanical properties at elevated temperatures and the test temperature are indicated in the technical documentation for semi-finished products intended for operation at elevated temperatures.
89. For the material of semi-finished products intended for operation at temperatures above 400 ° C, the creep resistance value of the metal is determined, which is indicated in the technical documentation.
90. The limits of the use of pipe material, types of tests and control are established by the regulatory and technical documentation and are indicated in the technical documentation.
91. Seamless pipes are made from rolled or forged billets.
92. For each pipe, hydraulic tests. The value of the test pressure is indicated in the normative and technical documentation for pipes.
93. Pipes are supplied in a heat-treated state, providing a given level of mechanical properties and residual stresses.
At the end of each pipe, a stamp is placed containing the following data: heat number, steel grade, manufacturer and batch number.
94. Pipes with an internal diameter of 14 mm or more are controlled by non-destructive methods. Pipes with a diameter of less than 14 mm are controlled by the magnetic particle or capillary (color) method.
95. Pipes made of corrosion-resistant steels, if provided for by the project, are tested for a tendency to intergranular corrosion (hereinafter - ICC).
96. For the manufacture of forgings, use high-quality carbon, low-alloy, alloy and corrosion-resistant steels.
97. Forgings for pipeline parts are assigned to groups IV and IVK.
98. The dimensions of forgings are accepted taking into account machining allowances, dimensional tolerances, technological allowances and allowances for samples.
99. Forgings made of carbon, low-alloy and alloy steels, having one of the overall dimensions of more than 200 mm and a thickness of more than 50 mm, are subject to piece-by-piece testing by ultrasonic or other equivalent method.
At least 50% of the inspected forging volume is subjected to flaw detection. The control area is distributed evenly over the entire controlled surface.
100. Studs, nuts, flanges and lenses may be made from long products.
101. The material of the studs, nuts, flanges and lenses made of long products meets the technical requirements specified in the regulatory and technical documentation for these products.
102. Limits of application of steels of various grades for flanges and fasteners, types of rigorous testing and control comply with regulatory and technical documentation.
103. Materials of fasteners are selected in accordance with paragraph 34 of these Requirements.
104. Nuts and studs are made from steels of different grades, and when made from steel of the same grade - with different hardness. At the same time, the hardness of the nut is lower than the hardness of the stud by at least 10-15 HB.
Paragraph 4. Requirements for the manufacture of pipelines
105. Welding assembly units is produced in accordance with the requirements of technical documentation containing instructions on the technology of welding pipelines, the use of filler materials, the types and scope of control, on preliminary and concomitant heating and heat treatment.
106. The manufacture of assembly units is allowed to be carried out by organizations that have the technical capabilities and specialists to ensure the quality of manufacture of assembly units in full compliance with these Requirements.
107. During the manufacture, installation, repair, incoming control of pipes, forgings, parts of welded joints and welding materials for compliance with these Requirements and regulatory and technical documentation.
108. Pipes, forgings, parts and welding materials are completed with certificates and marked.
109. The scope and methods of incoming inspection of the metal of assembly units and pipeline elements comply with Appendix 5 of these Requirements.
110. In the absence of certificates or the necessary data in them, if the labels (tags) on the packages do not correspond to the data of the certificates, tests and control checks are carried out.
111. Pipes, forgings, parts and welding materials are presented for control in batches. Control methods comply with the requirements of the technical specifications for delivery.
112. Inspection of the outer surface of pipes, parts and forgings is allowed to be carried out without the use of magnifying devices. The inner surface of the pipes is inspected using instruments.
If risks, captivity, sunsets, flaws are detected, the depth of which goes beyond the tolerances established by the technical requirements, the pipes are rejected.
113. Zakovy, captivity, sandboxes, shells, found by external inspection on the machined surfaces of forgings, are allowed provided that their depth does not exceed 75% of the actual, one-sided allowance for technological processing.
114. Pipes and forgings with the highest and lowest hardness are selected for mechanical testing.
115. From one end of each selected pipe cut off:
1) 2 specimens for tensile testing at 20°C;
3) 2 samples for tensile testing at operating temperature;
4) 2 samples for impact bending tests at negative temperature;
5) 1 sample for microstructure research;
6) 1 specimen for flattening test;
7) 1 specimen for static bending test.
116. From each selected forging cut out:
1) 1 specimen for tensile test at 20°C;
2) 2 test specimens for impact bending at 20°C;
3) 1 sample for tensile test at operating temperature;
4) 2 samples for impact bending tests at negative temperature.
117. Sampling for testing resistance to intergranular corrosion is carried out in accordance with regulatory and technical documentation.
118. The need for tests for resistance against intergranular corrosion of pipes, forgings, deposited metal or metal of a welded joint, determination of the content of the ferrite phase is established by the project.
119. For macro-examination of pipe metal, it is allowed to use samples on which impact bending was determined.
120. In case of unsatisfactory results of tests carried out in accordance with the requirements of paragraphs 114-116, at least for one of the indicators, it is repeated tests on a double number of samples taken from other pipes (forgings) of the same batch.
In case of unsatisfactory results of repeated tests, repeated tests of each pipe (forging) are carried out. Pipes (forgings) that have shown unsatisfactory results are rejected.
121. The chemical composition of the metal of pipes, forgings, parts is indicated in the certificates for the workpiece.
122. The metal of pipes and forgings made of steel grade 03X17H14M3 is subjected to control for the content of the ferrite phase. The content of the ferrite phase does not exceed 0.5 points (1-2%).
123. On the surfaces of finished bends and bends, traces of clamping matrices are allowed.
124. Deviations of the overall dimensions of assembly units correspond to the 16th grade. The total deviation of the overall dimensions of the assembly unit does not exceed ± 10 mm.
125. Overall dimensions and weight of assembly units, including those in packaging, do not exceed the established dimensions and loads for transportation by vehicles.
126. The displacement of the edges along the inner diameter in the butt welds of pipes and pipeline parts is allowed within 10% of the wall thickness, but not more than 1 mm. With a displacement of more than 1 mm, a boring is made along the inner diameter at an angle of 12-15 °. The boring depth does not go beyond the calculated wall thickness.
127. The offset of the edges along the outer diameter in the butt welds of pipes and pipeline parts does not exceed 30% of the thickness of a thinner pipe or part, but not more than 5 mm. If the specified values are exceeded, a bevel is made on the outside of the pipe or pipeline part at an angle of 12-15°. When assembling pipes with pipeline parts on which bevel is not allowed, adapters should be used that provide allowable displacement.
GOSGORTEKHNADZOR OF RUSSIA
APPROVED
Decree No. 11
Gosgortekhnadzor of Russia
from 02.03.95
DEVICE RULES
AND SAFE OPERATION
PROCESS PIPING
Mandatory for all enterprises and organizations
regardless departmental affiliation And
organizational and legal forms
PB 03-108-96
Editorial committee: E. A. Malov (chairman), A. A. Shatalov (deputy chairman), L. N. Ganshina, B. M. Gusev, S. I. Zusmanovskaya, G. V. Kiryukhin, V. N. Konovalov, N. V. Martynov, Yu. S. Medvedev, E. Ya. Neiman, N. A. Potapov, V. B. Serebryany, R. A. Standrik, S. G. Starodub, G. M. Khazhinsky, N. V. Khimchenko, M. P. Elyash.
"Rules for the arrangement and safe operation of technological pipelines" were developed by the Gosgortekhnadzor of Russia, the Nizhne-Volzhsky District of the Gosgortekhnadzor of Russia, research and design institutes: VNIKTIneftekhimoborudovaniye, NIIkhimmash, Giprokhimmontazh, IrkutskNIIkhimmash, GIAP, VNIIneftemash, VNIPIneft, YuzhNIIgiprogaz, JSC "Sintezproekt", VNIImontazhspetsstroy with taking into account the comments of the Bashkir district of the Gosgortekhnadzor of Russia, JSC "Angarskaya oil company”, Salavatnefteorgsintez OJSC, Kuibyshevazot CJSC, NIIPTkhimnefteapparatura, Nizhnekamskneftekhim OJSC and other interested organizations and enterprises.
These Rules establish general provisions and basic technical requirements for process pipelines: conditions for the selection and use of pipes, pipeline parts, fittings and basic materials for their manufacture, as well as requirements for welding and heat treatment, placement of pipelines, conditions for normal operation and repair, compliance with which is mandatory for all industries that have production facilities controlled by the Gosgortekhnadzor of Russia.
With the introduction of these Rules, the “Rules for the Construction and Safe Operation of Pipelines for Combustible, Toxic and Liquefied Gases (PUG-69)”, approved by the USSR Gosgortekhnadzor in 1969, become invalid.
All current industry normative and technical documents and instructions regarding the design, installation, operation and repair of steel in-plant and shop process pipelines must be brought into line with these Rules.
The need for and timing of bringing existing pipelines in line with these Rules are determined by the administration of the enterprise and agreed with the regional bodies of the Gosgortekhnadzor of Russia.
1. GENERAL PROVISIONS
1.1. Application area
1.1.1. The rules for the design and safe operation of process pipelines* apply to the design, installation, manufacture, installation, operation and repair of stationary steel process pipelines designed to transport gaseous, vaporous and liquid media in the range from a residual pressure (vacuum) of 0.001 MPa (0.01 kgf / cm 2) up to a nominal pressure of 320 MPa (3200 kgf / cm 2) and operating temperatures from minus 196 to plus 700 ° C at chemical, petrochemical, oil refining, gas processing, chemical-pharmaceutical, pulp and paper, microbiological, coke-chemical, oil and gas companies.
* Rules for the construction and safe operation of technological pipelines, hereinafter referred to as the Rules.
Notes. 1. Process pipelines include pipelines within industrial enterprises through which raw materials, semi-finished products and finished products, steam, water, fuel, reagents and other substances that ensure the maintenance technological process and equipment operation, as well as inter-factory pipelines, which are on the balance sheet of the enterprise.
2. The terms "pressure", "conditional pressure", except for specially stipulated cases, should be understood as excess pressure.
1.1.2. Along with these Rules, when designing, constructing and operating technological pipelines, one should also be guided by the relevant sections of the Construction Norms and Rules (SNiP), the relevant rules of the Gosgortekhnadzor of Russia and other mandatory rules and regulations.
In this case, it is necessary to take into account the requirements of fire and explosion safety, industrial sanitation and labor protection, set out in the relevant regulatory and technical documents (NTD), approved in the prescribed manner.
1.1.3. When designing and operating pipelines for liquid and gaseous chlorine, along with these Rules, one should be guided by the Safety Rules for the Production, Storage, Transportation and Use of Chlorine (PBH-93).
1.1.4. When designing and operating air and inert gas pipelines, along with these Rules, one should be guided by the requirements of the Rules for the Design and Safe Operation of Stationary compressor units, air ducts and gas pipelines.
1.1.5. When designing and operating pipelines transporting gas containing hydrogen sulfide, along with these Rules, one should be guided by industry NTD, agreed with the Gosgortekhnadzor of Russia, and recommendations of specialized research organizations.
1.1.6. These Rules do not apply to pipelines:
main (gas pipelines, oil pipelines and product pipelines);
acetylene and oxygen;
power plants, boiler houses, mines;
heating networks, water supply and sewerage lines;
lined with non-metallic materials;
gases containing explosive dust and fiber;
temporary, constructed for the period of construction, installation or reconstruction of an enterprise or workshop, with a service life of not more than 1 year;
special purpose (nuclear plants, mobile units, lubrication systems that are an integral part of the equipment, etc.);
steam and hot water of category I with a diameter of 51 mm or more, as well as all other categories with a diameter of 76 mm or more, which are subject to the requirements of the Rules for the Design and Safe Operation of Steam and Hot Water Pipelines;
fuel gas, which are subject to the Safety Rules in the gas sector, when using gas from main and city gas pipelines or liquefied gases as fuel.
1.1.7. Depending on the working pressure, process pipelines covered by these Rules are divided into process pipelines low pressure with nominal pressure up to 10 MPa (100 kgf / cm 2) inclusive and high-pressure process pipelines with nominal pressure over 10 MPa (100 kgf / cm 2) up to 320 MPa (3200 kgf / cm 2).
1.1.8. It is allowed to develop sectoral regulatory documents regulating the conditions and requirements of a particular industry, within the framework of the main provisions and requirements of these Rules.
1.2. Key points
1.2.1. These Rules establish the basic technical requirements for the design, installation, manufacture, installation, operation and repair of technological steel pipelines, as well as the conditions for the selection and use of pipes, pipeline parts, fittings and basic materials. Compliance with these Rules is mandatory for all enterprises and organizations involved in the design, manufacture, installation and operation of technological pipelines, regardless of departmental subordination and organizational and legal forms.
1.2.2. For pipes, fittings and connecting parts of pipelines, conditional ( R y) and the corresponding test ones ( R pr), as well as workers ( R slave) pressures are determined according to GOST 356. At a negative working temperature of the medium, the conditional pressure is determined at a temperature of plus 20 °C.
1.2.3. The wall thickness of pipes and pipeline parts should be determined by strength calculation depending on the operating (calculated) parameters, corrosion and erosion properties of the medium in accordance with regulatory and technical documents in relation to the current range of pipes. When choosing the wall thickness of pipes and pipeline parts, the features of their manufacturing technology (bending, assembly, welding) should be taken into account.
For the maximum working (calculated) pressure in the pipeline is taken:
permitted pressure for the apparatus to which the pipeline is connected;
for pressure pipelines (after pumps, compressors, gas blowers) - the maximum pressure developed by a centrifugal machine with a closed valve on the discharge side; and for reciprocating machines - the response pressure of the safety valve installed on the pressure source;
for pipelines with safety valves installed on them - the pressure of the safety valve.
Pipelines that are subjected to a strength and density test together with the apparatus must be designed for strength taking into account the pressure of the apparatus being tested.
1.2.4. When calculating the thickness of the walls of pipelines, the allowance for compensation of corrosive wear to the calculated wall thickness must be selected based on the condition for ensuring the necessary service life of the pipeline in accordance with the current standards for the use of materials in technological processes and the corrosion rate.
Depending on the corrosion rate of carbon steels, the media are divided into:
non-aggressive and low-aggressive - with a corrosion rate of up to 0.1 mm / year;
medium aggressive - with a corrosion rate of 0.1-0.5 mm / year;
highly aggressive - with a corrosion rate of more than 0.5 mm / year.
1.2.5. When choosing materials and products for pipelines, one should be guided by the requirements of these Rules, as well as the instructions of industry and inter-industry RTDs that establish their assortment, nomenclature, types, basic parameters, conditions of use, etc. This should take into account:
working pressure and working temperature of the transported medium;
properties of the transported and environment(aggressiveness, explosion and fire hazard, harmfulness, etc.);
properties of materials and products (strength, cold resistance, corrosion resistance, weldability, etc.);
ambient air temperature for pipelines located in the open air or in unheated premises. For the design air temperature when choosing materials and products for pipelines, the average temperature of the coldest five-day period should be taken in accordance with SNiP 2.01.01-82.
1.2.6. For the choice of the pipeline scheme, the correctness of its design, the calculation of strength and the choice of material, for the accepted service life, the quality of manufacture, installation and repair, as well as for the compliance of the pipeline with the requirements of rules, standards and other RTDs, the organizations or enterprises that performed the relevant work are responsible.
1.2.7. All design changes that occur during the manufacture, installation and repair of the pipeline, including the replacement of materials, parts and changes in the category of pipelines, must be carried out by an organization licensed by the Gosgortekhnadzor of Russia for the right to design pipelines.
1.2.8. The organization operating the pipeline (pipeline owner) is responsible full responsibility for the correct and safe operation of the pipeline, control over its operation, for the timeliness and quality of the audit and repair in accordance with these Rules, as well as for the coordination with the author of the project of all changes made to the facility and project documentation.
1.2.9. For pipelines and fittings in contact with explosive and hazardous environments, the design organization establishes the estimated service life, which should be reflected in the design documentation and included in the pipeline passport.
The operation of pipelines that have completed their estimated service life is allowed upon receipt of a technical opinion on the possibility of its further operation and permission in the manner prescribed by regulatory documents.
1.2.10. Organizations engaged in the design, manufacture, installation, repair, operation and technical diagnostics pipelines must have a license from the Gosgortekhnadzor of Russia for the work performed.
2. TECHNOLOGICAL PIPELINES WITH NOMINAL PRESSURE UP TO 10 MPa (100 kgf/cm 2)
2.1. Pipeline classification
2.1.1. All pipelines with pressure up to 10 MPa (100 kgf / cm 2) (inclusive), depending on the hazard class of the transported substance (explosion, fire and harmfulness), are divided into groups (A, B, C) and depending on the operating parameters of the environment ( pressure and temperature) - into five categories (I, II, III, IV, V).
The classification of pipelines is given in table. .
Table 2.1
Pipeline classification R at £ 10 MPa (100 kgf / cm 2)
| Transported substances | |||||||||||
| III | |||||||||||
| R slave, MPa (kgf / cm 2) | t slave, °С | R slave, MPa (kgf / cm 2) | t slave, °С | R slave, MPa (kgf / cm 2) | t slave, °С | R slave, MPa (kgf / cm 2) | t slave, °С | R slave, MPa (kgf / cm 2) | t slave, °С |
||
| Substances with a toxic effect | |||||||||||
| a) extremely and highly hazardous substances of classes 1, 2 (GOST 12.1.007 ) | Regardless | Regardless | |||||||||
| b) Class 3 moderately hazardous substances (GOST 12.1.007 ) | Over 2.5 (25) | Over +300 and below -40 | -40 to +300 | ||||||||
| Vacuum below 0.08 (0.8) (abs) | Regardless | ||||||||||
| Explosive and flammable substancesGOST 12.1.044 | |||||||||||
| a) combustible gases (GH), including liquefied gases (LHG) | Over 2.5 (25) | Over +300 and below -40 | Vacuum from 0.08 (0.8) (abs) to 2.5 (25) | -40 to +300 | |||||||
| Vacuum below 0.08 (0.8) (abs) | Regardless | ||||||||||
| b) flammable liquids (flammable liquids) | Over 2.5 (25) | Over +300 and below -40 | Over 1.6 (16) to 2.5 (25) | From +120 to +300 | Up to 1.6 (16) | -40 to +120 | |||||
| Vacuum below 0.08 (0.8) (abs) | Regardless | Vacuum above 0.08 (0.8) (abs) | -40 to +300 | ||||||||
| c) flammable liquids (GZh) | Over 6.3 (63) | Above +350 and below -40 | Over 2.5 (25) to 6.3 (63) | Over +250 to +350 | Over 1.6 (16) to 2.5 (25) | Over +120 to +250 | Up to 1.6 (16) | -40 to +120 | |||
| Vacuum below 0.003 (0.03) (abs) | Same | Vacuum below 0.08 (0.8) (abs) | Same | Vacuum up to 0.08 (0.8) (abs) | Over +350 to +450 | Over 2.5 (25) to 6.3 (63) | +250 to +350 | Over 1.6 (16) to 2.5 (25) | Over +120 to +250 | Up to 1.6 (16) | -40 to +120 |
Notes. 1. The designation of a group of a certain transported medium includes the designation general group environment (A, B, C) and the designation of the subgroup (a, b, c), reflecting the hazard class of the transported substance.
2. The designation of the pipeline group in general terms corresponds to the designation of the group of the transported medium. The designation "pipeline of group A(b)" means a pipeline through which a medium of group A(b) is transported.
3. The group of a pipeline transporting media consisting of various components is established according to the component that requires the pipeline to be assigned to a more responsible group. Moreover, if the concentration of one of the components in the mixture of dangerous substances of hazard classes 1, 2 and 3 is lethal, the group of the mixture is determined by this substance.
In the event that the most dangerous component in terms of physical and chemical properties is included in the composition of the mixture in an insignificant amount, the issue of assigning the pipeline to a less responsible group or category is decided by the design organization (project author).
4. The hazard class of harmful substances should be determined in accordance with GOST 12.1.005 and GOST 12.1.007, the values of the fire and explosion hazard indicators of substances - according to the relevant NTD or the methods set forth in GOST 12.1.044.
6. For vacuum pipes, it is not the nominal pressure that should be taken into account, but the absolute operating pressure.
7. Pipelines transporting substances with a working temperature equal to or higher than their auto-ignition temperature or a working temperature below minus 40 ° C, as well as those incompatible with water or atmospheric oxygen under normal conditions, should be assigned to category I.
2.1.2. The categories of pipelines determine the set technical requirements imposed on the design, installation and scope of control of pipelines in accordance with these Rules.
2.1.3. The hazard class of process media is determined by the project developer based on the hazard classes of substances contained in the process environment and their ratios in accordance with GOST 12.1.007.
2.1.5. By the decision of the developer, it is allowed, depending on the operating conditions, to take a more responsible (than determined by the operating parameters of the environment) category of pipelines.
2.2. Requirements for materials used for pipelines
2.2.1. Pipes, fittings, flanges, gaskets and fasteners used for steel process pipelines, in terms of quality, technical characteristics and materials, must meet the requirements of these Rules and relevant regulatory and technical documents.
The quality and technical characteristics of materials and finished products used for the manufacture of pipelines must be confirmed by manufacturers with the appropriate passports or certificates. Materials and products that do not have passports or certificates are allowed to be used only for pipelines of categories II and below and only after they have been checked and tested in accordance with the standards, specifications and these Rules.
The material of pipeline parts, as a rule, must correspond to the material of the pipes to be connected. When using and welding dissimilar steels, one should be guided by the instructions of the relevant regulatory and technical documents.
It is allowed, upon the conclusion of specialized research organizations, to use pipes and pipeline parts from materials not specified in these Rules.
2.2.2. Pipes and fittings of pipelines must be made of steel with technological weldability, with a ratio of yield strength to tensile strength of not more than 0.75, a relative elongation of the metal at break on five-fold samples of at least 16% and an impact strength of not less thanKCU = 30 J / cm 2 (3.0 kgf · m / cm 2) at the minimum temperature of the pipeline element wall during operation.
2.2.3. The use of imported materials and products is allowed if the characteristics of these materials meet the requirements domestic standards and confirmed by the conclusion of a specialized research organization.
Order Federal Service on Environmental, Technological and Nuclear Supervision dated December 27, 2012 No. 784 "0b Approval of the Safety Guide "Recommendations for the Construction and Safe Operation of Process Pipelines"I. General provisions
II. Recommended piping classification
III. Construction and material design of pipelines
IV Application of pipeline fittings
V. Recommendations for piping
VI. Recommendations for the installation of pipelines
VII. Requirements for welding and heat treatment
VIII. Testing and acceptance of installed pipelines
IX. Recommendations for the operation of the pipeline
X. Underground pipelines
XI. Execution of repair and installation works
Annex 1. Terms, definitions and abbreviations
Appendix 2. Passport of the pipeline
Annex 3. Recommended classification of pipelines
Appendix 4 Recommended Sealing Face Types for Soft Gasket Flanges
Appendix 5. Recommended Materials for Steel Piping and Piping Parts
Appendix 6
Annex 7. Recommended scope of incoming inspection of assembly units and pipeline elements
Appendix 8. Valve Passport
Appendix 9. Recommended distances between the axes of adjacent pipelines and from pipelines to the walls of channels and walls of buildings, mm, not less than
Appendix 10. Recommended minimum vertical distance from the upper technological pipelines of the overpass to power lines (lower wires, taking into account their sagging)
Annex 11.
Appendix 12. Deviation from perpendicularity to the axis of the flange sealing surface
Appendix 13. Permissible displacement of the inner edges when assembling pipe joints
Appendix 14. Recommended parameters for assessing the quality of welded joints in pipelines based on the results of visual and radiographic control depending on bulk defects (inclusions, pores)
Appendix 15. Recommended scope of ultrasonic or radiographic inspection of welded joints as a percentage of the total number of joints welded by each welder
Annex 16
Annex 17. Permissible defects in welds pipelines PN no more than 10 MPa, detected during ultrasonic testing
Appendix 18. Recommended assessment of the quality of welded joints by hardness
Annex 19. Permissible sample sizes after removal of defects in pipeline welds
Appendix 20. Recommended number of control welded joints for mechanical testing and metallographic studies
Appendix 21. Mechanical properties of welded joints
Appendix 22. Recommended frequency of inspections of pipelines with pressure up to 10 MPa
Appendix 23. Recommended values of pipe underruns when assembling pipes and parts with flat welded flanges, depending on the nominal diameter of the pipe
9.1. Supervision and maintenance
9.1.1. The administration of the enterprise - the owner of pipelines is obliged to maintain them in accordance with the requirements of these Rules, as well as other applicable inter-industry and departmental norms and rules, ensuring the safety of service and reliability of work.
Operation, supervision, revision and repair of pipelines must be carried out in accordance with the instructions developed on the basis of these Rules.
9.1.2. Persons who supervise pipelines at the enterprise, as well as persons responsible for the good condition and safe operation of pipelines, should be appointed by order of the enterprise from among the engineers who have the appropriate qualifications and practical experience, who have been certified in accordance with the "Regulations on the procedure for testing knowledge rules, regulations and instructions for safety executives and specialists of enterprises, organizations and facilities controlled by the Gosgortekhnadzor of Russia.
Quantity responsible persons for the implementation of supervision should be determined based on the calculation of the time required for the timely and high-quality performance of the duties assigned to these persons by official position.
9.1.3. For each installation (shop, production), the person responsible for the safe operation of pipelines must draw up a list of pipelines, made in two copies: one is kept by the person responsible for the safe operation of pipelines, the other - in the technical supervision service by the person supervising pipelines.
9.1.4. For all high-pressure pipelines [over 10 MPa (100 kgf/cm)] and low-pressure pipelines [up to 10 MPa (100 kgf/cm) inclusive] of categories I, II, III, as well as pipelines of all categories transporting substances at a corrosion rate pipeline metal 0.5 mm / year, the administration of the enterprise must draw up a passport of the established sample (Appendix 3).
The list of documents attached to the passport must comply with the requirements of section 9.4.
9.1.5. The passport for the pipeline must be kept by the person responsible for the safe operation of pipelines.
9.1.6. For pipelines that are not subject to the requirements of clause 9.1.4, it is necessary to keep an operating log at each installation, in which the dates of the audits carried out and data on the repairs of these pipelines should be entered.
9.1.7. Technological pipelines operating in hydrogen-containing media must be periodically inspected in order to assess the technical condition in accordance with the current regulatory and technical documents.
9.1.8. The maintenance of technological pipelines can be entrusted to persons who have reached the age of 18, trained according to a program developed in accordance with the requirements of these Rules and other NTD for pipelines, who know their scheme and have passed the knowledge test on safety regulations.
9.1.9. Persons supervising high-pressure pipelines should keep a record book of periodic testing of the pipeline.
9.1.10. On pipelines made of carbon and silicon-manganese steel with a working temperature of 400°C and above, as well as pipelines made of chromium-molybdenum (working temperature 500°C and above) and high-alloy austenitic steel (working temperature 550°C and above), monitoring of the growth of residual deformations. Observation, control measurements and cuttings are made in accordance with the instructions developed by the owner of the pipeline on the basis of " Model Instruction for monitoring and extending the service life of the metal of the main elements of boilers, turbines and pipelines of thermal power plants. RD 34.17.421-92" and agreed with a specialized research organization.
9.2. Supervision during operation
9.2.1. During the operation of pipelines, one of the main duties of maintenance personnel is constant and careful monitoring of the condition of the outer surface of pipelines and their parts (welds, flange connections, including fasteners, fittings), corrosion protection and insulation, drainage devices, compensators, supporting structures, etc. .d. The results of inspections should be recorded in the logbook at least once per shift.
9.2.2. Supervision over the correct operation of pipelines is carried out daily by the person responsible for the safe operation of pipelines, periodically - by the technical supervision service together with the management of the workshop and the person responsible for the safe operation of pipelines, at least once a year.
9.2.3. During a periodic inspection, it is necessary to check:
technical condition of pipelines by external inspection and, if necessary, non-destructive testing in places of increased corrosion and erosion wear, loaded sections, etc.;
elimination of comments on the previous inspection and implementation of measures for the safe operation of pipelines, provided for by the instructions of the state technical supervision bodies and the technical supervision service of the enterprise, orders and instructions, accident investigation reports and protocols of technical meetings;
completeness and procedure for maintaining technical documentation for the operation and repair of pipelines.
The results of the periodic inspection of pipelines are documented in an act, one copy of which is transferred to the head of the workshop of the owner of the pipeline.
9.2.4. Pipelines subject to vibration, as well as foundations under supports and overpasses for these pipelines during the operation period, must be carefully inspected using instrumental control over the amplitude and frequency of vibration by the technical supervision service together with the administration of the shop (production) and the person responsible for the safe operation of pipelines.
Defects found in this case must be immediately eliminated.
The timing of inspections, depending on the specific conditions and condition of the pipelines, is established technical administration enterprises, but at least once every 3 months.
The maximum allowable vibration amplitude of technological pipelines is 0.2 mm at a vibration frequency of not more than 40 Hz.
9.2.5. External inspection of pipelines laid in an open way, during periodic inspections, can be carried out without removing the insulation. However, if the condition of the walls or welds of the pipelines is in doubt, then at the direction of the person supervising the operation of the pipelines, partial or complete removal of insulation should be carried out.
9.2.6. External inspection of pipelines laid in impassable channels or in the ground should be carried out by opening in separate sections with a length of at least 2 m. The number of sections, depending on the operating conditions, is established by the person responsible for safe operation.
9.2.7. If, during external inspection, leaks in detachable joints are found, the pressure in the pipeline must be reduced to atmospheric pressure, the temperature of hot pipelines must be up to plus 60 ° C, and the defects must be eliminated in compliance with the necessary safety measures.
If defects are found, the elimination of which is associated with hot work, the pipeline must be stopped, prepared for repair work in accordance with applicable instructions, and the defects eliminated.
The person responsible for the safe operation of pipelines is responsible for the timely elimination of defects.
9.2.8. During the external examination, the condition should be checked:
insulation and coatings;
welded seams;
flange and coupling connections, fasteners and devices for installing instrumentation;
supports;
compensating devices;
drainage devices;
reinforcement and its seals;
benchmarks for measuring residual deformation;
welded tee joints, bends and bends.
At the same time, the vibration of the pipeline is checked.
9.3. Pipeline revision
9.3.1. The main method of monitoring the reliable and safe operation of technological pipelines is a periodic audit, which is carried out by the technical supervision service together with mechanics, heads of installations (productions).
The results of the audit serve as the basis for assessing the condition of the pipeline and the possibility of its further operation.
9.3.2. As a rule, the revision of pipelines should be timed to the scheduled preventive maintenance of individual units, installations or workshops.
9.3.3. The timing of the inspection of pipelines at pressures up to 10 MPa (100 kgf / cm) is set by the administration of the enterprise, depending on the rate of corrosion and erosion wear of pipelines, operating experience, the results of the previous external inspection, revision. The terms should ensure safe, trouble-free operation of the pipeline in the period between revisions and should not be less than those indicated in Table. 9.1.
Table 9.1
Periodicity of revisions of process pipelines with pressure up to 10 MPa (100 kgf/cm)
|
Transported media |
Inspection frequency at corrosion rate, mm/year |
|||
|
over 0.5 |
0,1 - 0,5 |
up to 0.1 |
||
|
Extremely, highly and moderately hazardous substances of classes 1, 2, 3 according to GOST 12.1.007-76 and high-temperature organic heat transfer fluids (HOT) (group A media) |
I and II |
At least once a year |
||
|
Explosive and flammable substances (HE), combustible gases (GH), including liquefied, flammable liquids (flammable liquids) in accordance with GOST 12.1.007-76 [environments of group B (a), B (b)] |
I and II |
At least once a year |
At least once every 2 years |
At least once every 3 years |
|
At least once a year |
At least once every 3 years |
|||
|
Combustible liquids (CL) in accordance with GOST 12.1.004-76 [environments of group B (c)] |
I and II |
At least once a year |
At least once every 2 years |
At least once every 3 years |
|
III and IV |
At least once a year |
At least once every 3 years |
At least once every 4 years |
|
|
Slow-burning (TG) and non-combustible (NG) substances according to GOST 12.1.004-76 (Group B media) |
I and II |
At least once every 2 years |
At least once every 4 years |
At least once every 6 years |
|
III, IV and V |
At least once every 3 years |
At least once every 6 years |
At least once every 8 years |
|
9.3.4. For high pressure pipelines [over 10 MPa (100 kgf / cm )], the following types of revision are established: selective, general selective and complete. The timing of the selective audit is set by the administration of the enterprise, depending on the operating conditions, but at least once every 4 years.
The first selective revision of pipelines transporting non-aggressive or slightly aggressive media must be carried out no later than 2 years after the pipeline is put into operation.
9.3.5. Postponement in the audit of pipelines in case of operational need is determined by the administration of the enterprise, taking into account the results of the previous audit and the technical condition of the pipelines, ensuring their further reliable operation, and is issued in writing for a period of not more than one year.
9.3.6. When conducting an audit, special attention should be paid to areas operating in particularly difficult conditions, where the maximum wear of the pipeline due to corrosion, erosion, vibration and other reasons is most likely. These include areas where the direction of flow changes (elbows, tees, tie-ins, drainage devices, as well as sections of pipelines before and after fittings) and where accumulation of moisture, substances that cause corrosion is possible (dead ends and temporarily inoperative sections).
9.3.7. An audit should be started only after the necessary preparatory work has been completed, provided for by the current instructions for the organization and safe performance of repair work.
9.3.8. When inspecting pipelines with pressures up to 10 MPa (100 kgf/cm), it is necessary:
a) conduct an external inspection of the pipeline in accordance with the requirements of clause 9.2.8;
b) measure the thickness of the pipeline wall with non-destructive testing devices, and, if necessary, by through drilling with subsequent welding of the hole.
The number of sections for thickness measurement and the number of measurement points for each section is determined by the person supervising the operation of pipelines, together with the person responsible for the safe operation of pipelines.
The wall thickness is measured in areas operating in the most difficult conditions (elbows, tees, tie-ins, places of narrowing of the pipeline, before and after fittings, places of accumulation of moisture and products that cause corrosion, stagnant zones, drainages), as well as in straight sections of intra-installation, intrashop and intershop pipelines.
At the same time, on straight sections of intra-installation pipelines with a length of 20 m or less and inter-workshop pipelines with a length of 100 m or less, wall thickness measurements must be performed at least in three places.
In all cases, the wall thickness control in each place should be carried out at 3 - 4 points along the perimeter, and on bends - at least 4 - 6 points along the convex and concave parts.
It is necessary to ensure the correctness and accuracy of measurements, to exclude the influence of foreign bodies on them (burrs, coke, corrosion products, etc.), and also to check measuring instruments and devices in a timely manner.
The measurement results are recorded in the pipeline passport.
Notes. 1. An audit of permanent sections of flare lines that do not have bypasses is carried out without turning them off by measuring the wall thickness with ultrasonic thickness gauges and washing the flange connections.
2. The issue of partial or complete removal of insulation during the inspection of pipelines is decided by the person supervising the operation of pipelines.
3. On pipelines made of austenitic grade steels (08X18H10T, 12X18H10T, etc.) operating in media that cause intergranular corrosion, through drilling is not allowed.
c) inspect flange collars by internal inspection (when disassembling the pipeline) or by measuring the thickness by non-destructive testing methods (ultrasonic or radiographic) at least at three points around the circumference of the flange collar. The wall thickness of the flange collar can also be controlled by means of control drillings. The number of flanges subject to revision is determined by the person supervising the operation of pipelines, depending on the operating conditions;
d) conduct an internal inspection of the pipeline section using a lamp, an RVP-type device, a magnifying glass, an endoscope or other means, if as a result of measuring the wall thickness and tapping the pipeline there are doubts about its condition; In this case, the inner surface must be cleaned of dirt and deposits, and, if necessary, pickled. In this case, you should choose a site operated in the most unfavorable conditions (where corrosion and erosion, water hammer, vibration, change in flow direction, stagnant zones are possible). The dismantling of a pipeline section in the presence of detachable connections is carried out by disassembling them, and this section is cut out on an all-welded pipeline.
During the inspection, check for corrosion, cracks, reduction in wall thickness of pipes and pipeline parts;
e) carry out radiographic or ultrasonic inspection of welded joints, if their quality during the audit raised doubts; if necessary, these welded joints should be subjected to metallographic and mechanical tests. The number of joints to be checked is determined by the person supervising the operation of pipelines;
f) check the mechanical properties of the metal of pipes operating at high temperatures and in hydrogen-containing media, if this is provided for by the current regulatory and technical documents or project. The mechanical properties of the metal should also be checked in cases where the corrosive action of the medium can cause them to change. The issue of mechanical testing is decided by the technical supervision service of the enterprise;
g) measure the deformation on the pipeline sections as of the time of the audit in accordance with the requirements of clause 9.1.10 and check the documentation for recording creep observations;
h) disassemble (optionally, at the direction of the representative of technical supervision) threaded connections on the pipeline, inspect them and measure them with thread gauges;
i) check the condition and correct operation of supports, fasteners and, optionally, gaskets;
j) test the pipeline in accordance with these Rules.
9.3.9. If the inspection results are unsatisfactory, it is necessary to determine the boundary of the defective section of the pipeline (inspect the inner surface, measure the thickness, etc.) and perform more frequent measurements of the wall thickness of the entire pipeline at the discretion of the technical supervision representatives.
9.3.10. The volume of selective revision of high pressure pipelines [over 10 MPa (100 kgf/cm)] should be:
at least two sections of each unit of the installation, regardless of temperature;
at least one section of each general workshop collector or inter-shop pipeline, regardless of the temperature of the medium.
The unit is understood as a group of devices and machines connected by piping and designed to carry out a certain part of the technological process (for example, a gas separation unit, a compressor unit, etc.).
A collector is a pipeline that connects a number of units operating in parallel.
9.3.11. The selection of sites for revision is made by the person responsible for the good condition and safe operation of pipelines, together with the technical supervision service. When choosing, you should identify areas operating in the most severe conditions, where wear is most likely to occur due to corrosion, erosion, vibration and other causes. When choosing a site, the results of the previous external examination and previous revisions should be taken into account.
9.3.12. When inspecting the control section of the high-pressure pipeline, it is necessary:
a) conduct an external examination in accordance with the requirements of clause 9.2.8;
b) if there are flange or socket connections, disassemble them, then inspect the pipeline internally;
c) to measure the thickness of the walls of pipes and other parts of the control section with non-destructive testing devices;
d) if defects are found in the welds (near-weld zone) during the inspection or if there are doubts about their quality, carry out control by non-destructive methods (radiographic, ultrasonic, etc.);
e) if there are doubts about the quality of the metal, check its mechanical properties and chemical composition. The method of verification is determined by the technical supervision service;
f) check the condition of couplings, flanges, their mating surfaces and threads, gaskets, fasteners, as well as fittings and fittings, if any, in the control area;
h) carry out control for residual deformation in accordance with the requirements of clause 9.1.10, if it is provided for by the project;
g) to control the hardness of fasteners of flange joints operating at a temperature of 400°C.
9.3.13. The results of the audit are considered satisfactory if the detected deviations are within acceptable limits.
In case of unsatisfactory audit results, two more similar sections should be checked, of which one should be a continuation of the audited section, and the second - similar to the audited section.
9.3.14. If, on inspection of the high pressure pipeline, it is found that the original thickness has been reduced by corrosion or erosion, the operability must be confirmed by a strength calculation.
9.3.15. Upon receipt of unsatisfactory results of the audit of additional sections, a general selective audit of this pipeline, as well as sections of pipelines operating in similar conditions, with dismantling of up to 30% of each of these pipelines or less, with an appropriate technical justification issued by a specialized organization, should be carried out.
9.3.16. A general selective audit of high-pressure pipelines should also be carried out periodically at the following times:
a) in the production of ammonia:
pipelines intended for transportation of nitrogen-hydrogen and other hydrogen-containing gas mixtures at an ambient temperature of up to 200 ° C - after 24 years, at an ambient temperature of over 200 ° C - after 8 years;
b) in methanol production:
pipelines intended for the transportation of hydrogen gas mixtures containing, in addition to hydrogen, carbon monoxide, at an ambient temperature of up to 200 ° C - after 15 years, at an ambient temperature of more than 200 ° C - after 6 years;
c) in the production of caprolactam:
pipelines intended for transportation of hydrogen gas mixtures at ambient temperatures up to 200°C - after 10 years, pipelines intended for transportation of carbon monoxide at temperatures above 150°C - after 8 years;
d) in the production of synthetic fatty alcohols (SFA):
pipelines intended for transportation of hydrogen gas mixtures at ambient temperatures up to 200°C - after 10 years, at ambient temperatures above 200°C - after 8 years;
pipelines intended for transportation of paste (catalyst with methyl esters) at ambient temperatures up to 200°C - after 3 years;
e) in the production of urea:
pipelines intended for transporting the urea melt from the synthesis column to the throttling valve - after 1 year;
pipelines intended for transportation of ammonia from the heater to the mixer at an ambient temperature of up to 200°C - after 18 years;
pipelines designed to transport carbon dioxide from the compressor to the mixer at an ambient temperature of up to 200 ° C - after 6 years;
pipelines intended for transportation of carbon ammonium salts (carbamate) at ambient temperatures up to 200 ° C - after 4 years.
A general selective audit of pipelines intended for the transportation of other liquid and gaseous media and other industries should also be carried out:
at a corrosion rate of up to 0.1 mm/year and a temperature of up to 200°C - after 10 years;
the same at a temperature of 200 - 400 ° C - after 8 years;
for environments with a corrosion rate of up to 0.65 mm/year and an ambient temperature of up to 400°C - after 6 years.
In case of unsatisfactory results of the general selective audit, the administration of the enterprise appoints a full audit of the pipeline.
9.3.17. With a complete audit, the entire pipeline is completely disassembled, the condition of the pipes and parts, as well as the fittings installed on the pipeline, is checked. The terms and obligatoriness of a complete audit of pipelines are not regulated by these Rules and are determined by the bodies and persons exercising supervision, or by the administration of the enterprise, if the need for it is confirmed by the results of a general selective audit.
9.3.18. All pipelines and their sections subjected to disassembly, cutting and welding during the audit, after assembly, are subject to a strength and density test.
For pipelines with P10 MPa (100 kgf/cm) when disassembling single flange connections associated with the replacement of gaskets, fittings or individual elements (tee, coil, etc.), it is allowed to test only for density. In this case, the newly installed fittings or pipeline element must first be tested for strength by test pressure.
9.3.19. After the audit, acts are drawn up, to which all the protocols and conclusions on the studies carried out are attached. The audit results are recorded in the pipeline passport. Acts and other documents are attached to the passport.
9.3.20. After the expiration of the design service life, the pipeline must be subjected to a comprehensive survey in order to establish the possibility and period of further operation in accordance with the requirements of these Rules and the current industry NTD.
Maintenance and revision of fittings
9.3.21. The fittings of technological pipelines are the most important element of communications, therefore, the necessary measures must be taken at enterprises to organize constant and thorough supervision of the serviceability of fittings, as well as timely and high-quality inspection and repair.
When using fittings with stuffing boxes, special attention should be paid to the stuffing material - quality, dimensions, correct installation in the stuffing box.
Stuffing for glands is selected in accordance with GOST 5152.
9.3.22. Asbestos packing, impregnated with a fatty composition and graphed, can be used for operating temperatures not higher than 200 ° C, since with higher heating, fatty substances flow out and the density of the stuffing box quickly decreases.
9.3.23. For temperatures above 200°C and pressures up to 25 MPa (250 kgf/cm2), it is possible to use asbestos-programmed packing. In addition, each ring must be sprinkled with a layer of dry clean graphite with a thickness of at least 1 mm.
9.3.25. For pressures above 32 MPa (320 kgf/cm) and temperatures above 200°C, the use of special packings in accordance with clause 9.3.24 is mandatory.
9.3.26. The stuffing box packing of the fittings must be made of a braided cord of square section with a side equal to the width of the stuffing box. From such a cord on a mandrel, blanks of rings with ends beveled at an angle of 45 ° should be cut.
9.3.27. The packing rings should be placed in the stuffing box opposite the cut lines with the seal of each ring. The height of the stuffing box packing should be such that the grundbox in the initial position enters the stuffing box no more than 1/6 - 1/7 of its height, but not less than 5 mm.
The glands should be tightened evenly without distortion of the gland box.
9.3.28. To ensure the tightness of the gland seal, it is necessary to monitor the cleanliness of the surface of the spindle and stem.
9.3.29. The gasket material for sealing the connection between the cover and the valve body should be selected taking into account the chemical effect of the transported medium on it, as well as depending on pressure and temperature in accordance with clause 2.2.26 of these Rules.
9.3.30. The spindle stroke in gate valves and valves must be smooth, and the valve must move without jamming when closing or opening valves.
9.3.31. Relief valves must be serviced in accordance with industry and manufacturer's guidelines.
9.3.32. To create tightness, the shut-off valves should be closed with normal force. It is not allowed to use additional levers when opening and closing valves.
9.3.33. Revision and repair of pipeline fittings, including non-return valves, as well as drive devices of fittings (electric, pneumatic, hydraulic, mechanical drive), as a rule, are carried out during the revision of the pipeline.
9.3.34. Revision and repair of fittings should be carried out in specialized workshops or at repair sites. In some cases, at the discretion of technical supervision, it is allowed to revise the fittings by disassembling and inspecting them directly at the installation site (welded fittings, large-sized, hard-to-reach, etc.).
9.3.35. When inspecting fittings, including check valves, the following work must be performed:
a) external examination;
b) disassembly and inspection of the condition of individual parts;
c) inspection of the internal surface and, if necessary, control by non-destructive methods;
d) lapping of sealing surfaces;
e) assembly, testing and pressure testing for strength and density.
9.3.36. When planning the revision and repair of valves, it is necessary first of all to carry out the revision and repair of valves operating in the most difficult conditions, while observing the principle of alternation. The results of repair and testing of fittings are documented in an act.
Control drilling
9.3.37. In cases where the nature and pattern of corrosion wear of the pipeline cannot be established by the control methods used in the audit, it is allowed to perform control drilling for timely signaling that the wall thickness is approaching the rejection size.
The need for control drilling is determined by the technical supervision service of the enterprise for each specific case, taking into account the restrictions set forth in paragraph 9.3.38.
9.3.38. Pipelines through which substances of groups A (a), A (b), gases of all groups, pipelines operating under vacuum and high pressure[over 10 MPa (100 kgf / cm )], pipelines in blocks of explosion category I, as well as pipelines made of steels of type 18-8 and operating in environments that cause intergranular corrosion, are not subjected to control drilling. In these cases, control over the condition of the pipeline wall thickness should be strengthened by measuring with an ultrasonic thickness gauge or by using through drilling.
9.3.39. When pilot holes are drilled, use a 2.5 - 5 mm diameter drill set at a sharp angle to prevent large product leaks in case of missing pilot holes.
9.3.40. Holes for control drilling should be located in places of turns, narrowings, tie-ins, stagnant zones, as well as in tees, drainage outlets, before and after shut-off valves, etc.
9.3.41. Control drilling holes on bends and half-bends should be located mainly along the outer radius of the bend at the rate of one hole per 0.2 m of length, but not less than one hole per bend or welded bend section.
9.3.42. The depth of control drilling should be equal to the calculated thickness plus PxS (where P is half the period between successive revisions, year, C is the actual corrosion rate of the pipeline, mm / year).
9.3.43. Pilot drilling locations on the pipeline must be clearly marked.
9.3.44. The passage of a control hole on the pipeline indicates the approach of the wall thickness to the rejection size, therefore, such a pipeline must be subjected to an extraordinary revision.
Periodic testing of pipelines
9.3.45. The reliability of pipelines is checked by periodic tests for strength and density in accordance with the requirements of Section 8 of these Rules.
When testing for strength and density, it is allowed to use acoustic emission control.
9.3.46. The frequency of testing pipelines for strength and density is timed to the time of the audit of the pipeline.
The timing of the test for pipelines with pressures up to 10 MPa (100 kgf / cm) should be equal to twice the frequency of the audit, adopted in accordance with the requirements of clause 9.3.3 for this pipeline, but at least once every 8 years.
The timing of the test for pipelines with pressures over 10 MPa (100 kgf / cm) should be (at least):
for pipelines with temperatures up to 200°C - once every 8 years;
for pipelines with temperatures above 200°C - once every 4 years.
9.3.47. The test pressure and test procedure must comply with the requirements of Section 8 of these Rules.
9.3.48. Periodic testing of pipelines is carried out under the guidance of a person responsible for safe operation, and is documented in an act (Appendix 8).
9.3.49. Persons responsible for the safe operation of pipelines, on the basis of the act, make an appropriate entry in the passport and indicate the date of the next test, and for pipelines for which the passport is not drawn up, an entry is made in the operating log.
Rejection rates
9.3.50. Pipes, pipeline parts, fittings, including cast ones (valve bodies, valves, valves, etc.), are subject to rejection:
if, as a result of the audit, it turns out that due to the influence of the environment, the wall thickness has become lower than the design one and has reached the value determined by the strength calculation without taking into account the allowance for corrosion (rejection size);
if the calculated wall thickness (without allowance for corrosion) turned out to be less than the value indicated below, then the following values are taken as the rejection size:
|
for pipes, pipeline parts: |
||||||||||||||||
|
outer diameter, mm |
(114) |
|||||||||||||||
|
for valve bodies, valves, valves and pipeline castings: |
||||||||||||||||
|
conditional pass, mm |
||||||||||||||||
|
smallest allowable wall thickness, mm |
||||||||||||||||
Note. As an exception, deviation from the established norms is allowed in some cases in agreement with the Gosgortekhnadzor of Russia if there is a positive conclusion from a design or specialized organization licensed by the Gosgortekhnadzor of Russia.
The rejection wall thickness of the pipeline elements must be indicated in the design documentation. Pipes and pipeline parts are rejected if:
during the revision, cracks, delaminations, deformations (corrugations, dents, swellings, etc.) were found on the surface;
as a result of the impact of the environment during operation until the next revision, the wall thickness will go beyond the rejection dimensions determined by the strength calculation;
the mechanical properties of the metal have changed and their rejection is required in accordance with the current regulatory and technical documents and these Rules;
when the welds were translucent, defects were found that could not be corrected;
dimensions threaded connections out of tolerance or there are thread breaks, cracks, corrosive wear;
the pipeline did not pass the hydraulic or pneumatic test;
the sealing elements of the fittings have worn out so much that they do not ensure the conduct of the technological process, and it is impossible to repair or replace them.
9.3.51. Flanges are rejected when:
unsatisfactory condition of mating surfaces;
the presence of cracks, shells and other defects;
flange deformations;
reducing the wall thickness of the flange collar to the rejection dimensions of the pipe;
thread breakage, crushing and wear in high-pressure threaded flanges, as well as in the presence of a backlash in the thread that exceeds the allowable according to the current NTD. Lenses and gaskets of oval section are rejected in the presence of cracks, nicks, chips, dents of sealing surfaces, deformation.
9.3.52. Fasteners are rejected:
when cracks, breakage or corrosive wear of the thread appear;
in cases of bending bolts and studs;
with residual deformation leading to a change in the thread profile;
in case of wear of the side faces of the heads of bolts and nuts;
in the event of a decrease in the mechanical properties of the metal below an acceptable level.
9.3.53. Bellows and lens expansion joints are rejected in the following cases:
the wall thickness of the bellows or lens has reached the calculated value specified in the compensator passport;
the wall thickness of the bellows has reached 0.5 mm in cases where the design thickness of the bellows is lower;
when operating time by compensators of type KO-2 and KS-2 is 500 cycles and by other types - 1000 cycles, if they are operated in fire-explosive and toxic environments, and the permissible number of cycles for these compensators, determined according to the method of OST 26-02-2079-83, exceeds specified in this paragraph;
when operating compensators allowable number of cycles, determined by the method described in OST 26-02-2079-83.
9.3.54. Rejection rates should be indicated in the repair documentation for a specific object.
9.4. Technical documentation
9.4.1. The following technical documentation is maintained for technological pipelines (appendices 3 - 10 to these Rules):
1. List of technological pipelines (Appendix 7).
2. Passport of the pipeline (Appendix 3). Attached are:
a pipeline diagram indicating the nominal bore, initial and rejection thickness of the pipeline elements, installation locations for fittings, flanges, plugs and other parts, places for drain, purge and drainage devices, welded joints, control drillings (if any) and their numbering;
acts of revision and rejection of pipeline elements (Appendix 5);
certificate of quality of pipeline repairs (Appendix 4). Source documents, including magazine welding work for the repair of pipelines (Appendix 4a), confirming the quality of the materials used in the repair and the quality of the welded joints, are stored in the organization that performed the work and presented for verification at the request of the technical supervision service;
documentation for the control of metal of pipelines operating in hydrogen-containing media, in accordance with the NTD.
3. The act of periodic external inspection of the pipeline.
4. The act of testing the pipeline for strength and density (Appendix 8).
5. Acts for the revision, repair and testing of fittings (appendices 6, 6a).
6. Operating log of pipelines (maintained for pipelines for which passports are not drawn up).
7. Journal of installation and removal of plugs (Appendix 9).
8. Journal of heat treatment of welded joints of pipelines (Appendix 10).
9. Conclusion on the quality of welded joints.
9.4.2. The specified technical documentation, together with the passport, is kept by the person responsible for the safe operation of the pipeline.
9.4.3. Forms of technical documentation are recommended. Depending on the structure and composition of the enterprise, it is allowed to make changes, provided that the main content is preserved.
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