Snip iii 42 80 main pipelines

26.04.2020

BUILDING REGULATIONS

MAIN PIPING

SNiP III-42-80*

DEVELOPED BY VNIIST of Minneftegazstroy with the participation of institutes Giprotruboprovod of Minnefteprom and Giprospetsgaz of Mingazprom

PREPARED FOR APPROVAL by the Office of Standards and technical standards in the construction of the Gosstroy of the USSR ( ON THE. Shishov), VNIIST (candidates of technical sciences IN AND. Prokofiev, V.P. Mentyukov).

SNiP III-42-80* is a reissue of SNiP III-42-80 with changes approved by the Decree of the USSR Gosstroy (Ministry of Construction of Russia): No. 272 dated November 5, 1982, No. 308 dated December 28, 1982, No. 71 dated December 29. 1986 and No. 18-79 dated 11/10/1996

Sections, paragraphs, tables, formulas, applications that have been amended are marked in these building codes and rules with an asterisk.

When using a normative document, the approved changes in building codes and rules and state standards should be taken into account.

1. GENERAL PROVISIONS

1.1. The rules of this chapter must be observed during the construction of new and reconstruction of existing main pipelines and branches from them with a nominal diameter of up to 1400 mm (inclusive) with an excess pressure of the medium not exceeding 10 MPa (100 kgf / cm 2) for transportation:

oil, oil products, natural and associated, natural and artificial hydrocarbon gases from the areas of their production (from the head pumping pumping and compressor stations), production or storage to the places of consumption (oil depots, transshipment bases, loading points, gas distribution stations of cities and settlements, individual industrial and agricultural enterprises and ports);

liquefied hydrocarbon gases (fractions C 3 and C 4 and mixtures thereof), as well as unstable gasoline and unstable condensate and other liquefied hydrocarbons with a saturated vapor pressure of not more than 1.6 MPa (16 kgf / cm 2) at a temperature of plus 45 ° C from areas of their extraction or production (from head pumping pumping stations) to the places of consumption (oil depots, transshipment depots, loading points, industrial enterprises, ports, gas distribution stations and cluster bases);

marketable products within the head and intermediate gas compressor and oil pumping stations, underground gas storage stations, gas distribution stations, metering points.

1.2*. The rules of this chapter do not apply to the construction of field pipelines, as well as the construction of main pipelines in offshore areas and areas with a seismic activity of more than 8 points for underground and more than 6 points for aboveground pipelines. In these cases, the requirements of the relevant departmental regulatory documents (VSN), approved in the prescribed manner, must be observed, and in their absence, the special requirements for the production and acceptance of work specified in project documentation.

1.3. During the construction of main pipelines, in addition to the requirements of this chapter, the requirements of SNiP 3.01.01-85*, SNiP III-4-80*, other building codes and rules, as well as standards and instructions governing production and acceptance certain types works in the main pipeline construction complex and approved in accordance with the established procedure.

1.5. The construction of main pipelines must be carried out in-line by mobile mechanized columns or complexes that ensure the continuity of all work in a strict technological sequence.

1.6. Preparatory work and the construction of crossings over natural and artificial obstacles should be carried out by specialized construction and installation units.

1.7. The width of the land allotment strip for the period of construction of main pipelines is determined by the project in accordance with SN 452-73 ..

1.8. When crossing a main pipeline under construction with underground utilities, construction and installation work is allowed with the permission of the organization operating these communications, and in the presence of its representatives.

1.9. If underground utilities and structures that are not listed in the design documentation are found at the work site, measures must be taken to protect them from damage in agreement with the organization operating these communications and structures.

1.10. When opening cable communication lines crossing the pipeline route, the Conditions for the performance of work within the security zones and clearings on the routes of communication and radio lines, approved by the USSR Ministry of Communications, must be observed.

1.11. In the production of construction and installation works, it must be carried out by the foremen of the work construction organizations operational control of their quality (for all technological processes). Representatives of the customer, as well as representatives of state supervision bodies, have the right to conduct selective quality control of all types of work. The use of materials and products for which there are no certificates, passports and other documents confirming their quality is not allowed.

1.12. During the construction of main pipelines, pipes should be used, mainly insulated in factory or basic conditions. The construction of pipelines from insulated pipes should be carried out according to special technological instructions.

1.13*. Registration of production documentation, including certificates of examination of hidden works, must be carried out in accordance with VSN 012-88, approved by the Minneftegazstroy.

1.14. Materials of the actual position of pipelines (executive survey), drawn up in accordance with the established procedure by construction and installation organizations and the customer, must be transferred to local authorities.

2. PREPARATORY WORK

2.1. The customer is obliged to create a geodetic marking base for construction and, at least 10 days before the start of construction and installation work, transfer to the contractor the technical documentation for it and for the points and signs of this base fixed on the pipeline construction route, including:

signs fixing the corners of the route;

leading signs of the turn angles of the route in the amount of at least two for each direction of the corner within visibility;

leading signs on straight sections of the route, installed in pairs within sight, but not less than 1 km apart;

leading signs for fixing straight sections of the route at crossings over rivers, ravines, roads and other natural and artificial obstacles in the amount of at least two on each side of the crossing within sight;

high-altitude benchmarks installed at least every 5 km along the route, except for those installed at crossings through water barriers (on both banks);

an explanatory note, outlines of the location of signs and their drawings;

catalogs of coordinates and marks of points of the geodetic base.

Permissible root-mean-square errors when constructing a geodesic stakeout:

angular measurements ± 2 " ;

linear measurements 1/1000;

determination of marks ± 50 mm.

2.2. Before the start of construction, the general contracting construction and installation organization must perform the following work on the route:

control the geodetic staking base with an accuracy of linear measurements of at least 1/500, angular 2 " and leveling between benchmarks with an accuracy of 50 mm per 1 km of the route. The route is accepted from the customer according to the act, if the measured lengths of the lines differ from the design ones by no more than 1/300 of the length, the angles are no more than 3 " and marks of signs, determined from the leveling between the benchmarks, - no more than 50 mm;

install additional signs (milestones, poles, etc.) along the axis of the route and along the boundaries of the construction strip;

bring out in nature the horizontal curves of a natural (elastic) bend after 10 m, and an artificial bend - after 2 m;

break up the picketage along the entire route and at its characteristic points (at the beginning, middle and end of curves, at the intersections of routes with underground utilities). The alignments of the broken points should be fixed with signs, as a rule, outside the area of construction and installation works. Install additional benchmarks after 2 km along the highway.

2.3. Prior to the start of the main construction and installation works, the general contractor must, if necessary, in addition to the requirements of SNiP 3.01.01-85*, perform the following preparatory work on the route, taking into account the specific construction conditions:

clear the pipeline right of way from forests, shrubs, stumps and boulders;

remove individual trees and overhanging parts of rocks and stones located outside the right of way, but threatening by their condition to fall into the area of the right of way;

cut steep longitudinal slopes;

to carry out protective anti-landslide and anti-landslide measures;

to carry out measures to ensure minimal freezing of the soil in the trench for the pipeline;

build temporary roads, culverts, drainage, and drainage facilities at the entrances to the highway and along it, as well as bridges and crossings over rivers, streams and ravines; protect access roads from snow drifts;

arrange temporary on-site and near-station bases or warehouses for storing materials and equipment;

arrange temporary piers and moorings;

prepare temporary production bases and sites for the production of welding, bitumen melting and other works;

build temporary settlements that provide the necessary housing, sanitary, cultural and living conditions for workers;

prepare helipads;

create a dispatch communication system;

prepare construction sites for construction and installation work on the construction of pipeline crossings through natural and artificial obstacles and when laying pipelines in tunnels with the necessary temporary amenity and technological premises, structures, roads;

create water metering posts outside the area of work on the arrangement of pipeline crossings through water barriers with linking the water metering post by leveling to the high-altitude survey of the pipeline route and the state geodetic network;

remove the fertile layer of the earth and move it to a dump for temporary storage in accordance with clause 13.8 of these building codes and regulations.

2.4. The clearing of the route for the period of construction should be carried out within the boundaries of the right of way and in other places established by the project.

In winter, clearing should be carried out in two stages: in the area of the passage of vehicles and the operation of construction vehicles - well in advance of the start of the main work, and in the area of digging a trench - immediately before the operation of earth-moving machines to a length that ensures their work during the shift.

2.5. Uprooting of stumps in dry sections of the route should be carried out over the entire width of the right of way, and in swampy areas - only on the strip of the future trench of the pipeline and cable. For the remainder of the ROW, trees must be cut down at ground level.

2.6. The scope of planning work required for transport purposes and the movement of construction vehicles must be specified in the construction organization project and specified in the work execution project.

2.7. Temporary roads for the passage of construction and transport vehicles should be arranged as single-lane with widening at the places of turns, turns and sidings (on the side of the pipeline opposite to the route of the cable communication line). Passages are arranged at a line-of-sight distance, but not more than 600 m.

During the construction of winter roads, it should be mainly limited to the compaction of the snow cover with the freezing of the ice crust, the freezing of the soil surface and the maintenance of the carriageway in good condition.

During the construction and operation of ice roads laid along rivers, streams and lakes, the bearing capacity of ice should be determined and work should be carried out to maintain the ice cover in working condition.

The type, design, width of roads and turning radii are determined by the construction organization project and are specified in the work execution project.

3. EARTHWORKS

3.1. The dimensions and profiles of the trenches are established by the project depending on the purpose and diameter of the pipelines, soil characteristics, hydrogeological and other conditions.

3.2. The width of the trenches along the bottom must be at least D+300 mm for pipelines up to 700 mm in diameter (where D- conditional diameter of the pipeline) and 1.5 D- for pipelines with a diameter of 700 mm or more, taking into account the following additional requirements:

for pipelines with a diameter of 1200 and 1400 mm when digging trenches with slopes not steeper than 1:0.5, the width of the trench along the bottom can be reduced to D + 500 mm;

in the development of soil earthmoving machines the width of the trenches should be taken equal to the width of the cutting edge of the working body of the machine, adopted by the construction organization project, but not less than that indicated above;

the width of the trenches along the bottom in curved sections from forced bending bends should be equal to twice the width in relation to the width in straight sections;

the width of the trenches along the bottom when ballasting the pipeline with weighting loads or fixing it with anchor devices must be at least 2.2 D, and for pipelines with thermal insulation is established by the project.

3.3. The steepness of slopes of trenches should be taken in accordance with SNiP 3.02.01-87, and those developed in swamps - according to Table. one.

Table 1

	The steepness of the slopes of trenches developed in swamps of the type
		III (heavily watered)
slightly decomposed
well decomposed		By project

In silty and quicksand soils that do not ensure the preservation of slopes, trenches are developed with fastening and drainage. Types of fastening and drainage measures for specific conditions should be established by the project.

3.4. When digging trenches with bucket-wheel excavators, in order to obtain a more even surface of the bottom of the trenches at the design level and ensure a snug fit of the laid pipeline to the base along the entire length along the axis of the pipeline at a width of at least 3 m, preliminary planning of the strip microrelief should be carried out in accordance with the project.

3.5. The development of trenches in swamps should be carried out with single-bucket backhoes on widened or conventional tracks from sledges, draglines or special machines.

When laying pipelines through swamps using the alloy method, it is advisable to develop trenches and floating peat crust using an explosive method, using elongated cord, concentrated or borehole charges.

Clauses 3.6 and 3.7 exclude.

3.8. In order to prevent deformation of the profile of the dug trench, as well as freezing of the soil heap, the shifting rates of insulation-laying and excavation work should be the same.

The technologically necessary gap between the earthmoving and insulating-laying columns must be indicated in the project for the production of works.

The development of trenches in the backlog in soils (with the exception of rocky ones in the summer), as a rule, is prohibited.

Explosive loosening of rocky soils should be carried out before the pipes are taken to the route, and loosening of frozen soils is allowed after laying the pipes on the route.

3.9. When developing trenches with preliminary loosening of rocky soil using a drilling and blasting method, soil sorting should be eliminated by adding soft soil and compacting it.

3.10. Foundations for pipelines in rocky and frozen soils should be leveled with a layer of soft soil with a thickness of at least 10 cm above the protruding parts of the foundation.

3.11. When constructing pipelines with a diameter of 1020 mm or more, the bottom of the trench should be leveled along the entire length of the route: on straight sections after 50 m; on vertical curves of elastic bending after 10 m; on vertical curves of forced bending after 2 m; when constructing pipelines with a diameter of less than 1020 mm only on difficult sections of the route (vertical angles of rotation, sections with rugged terrain), as well as at crossings over iron and car roads, ravines, streams, rivers, beams and other obstacles for which individual working drawings are developed

3  12  By the time the pipeline is laid, the bottom of the trench must be leveled in accordance with the project

Laying the pipeline in a trench that does not comply with the project is prohibited

3  13*  Backfilling of the trench is carried out immediately after the pipeline is lowered and ballast weights or anchor devices are installed, if the pipeline ballasting is provided for by the project Places for installation of stop valves, tees of control and measuring points of electrochemical protection are backfilled after their installation and welding of cathode leads

When backfilling the pipeline with soil containing frozen clods, crushed stone, gravel and other inclusions larger than 50 mm in diameter, the insulating coating should be protected from damage by adding soft soil to a thickness of 20 cm above the upper generatrix of the pipe or by installing protective coatings provided for by the project

Note. The post-shrinkage restoration of main pipelines (laying to design levels, restoration of design ballasting, backfilling of soil in trenches, restoration of embankments, etc.) is carried out in accordance with the procedure established by the Rules on Contracts for Capital Construction, approved by the Decree of the Council of Ministers of the USSR of December 24, 1969. No. 973.

table 2

	Tolerance value (deviation), cm
Half the width of the trench along the bottom in relation to the staking axis
Deviation of marks when planning a lane for the operation of bucket-wheel excavators
Deviation of trench bottom marks from the project:
when excavating soil with earthmoving machines
in the development of soil by drilling and blasting
The thickness of the bed layer of soft soil at the bottom of the trench
The thickness of the layer of powder from soft soil above the pipe (with subsequent backfilling with rocky or frozen soil)
The total thickness of the backfill layer above the pipeline
Embankment heightSNiP III-42 -80* « Trunkpipelines" Information about changes to this... The system of regulatory documents in the gas industry departmental guiding document rules for the technical operation of main gas pipelines Document Regulations"; SNiP 2.05.06-85* "Trunkpipelines"; SNiPIII-42 -80* "Rules for the production and acceptance of work. Trunkpipelines"; SNiP 3.05.05 ... RULES FOR THE DEVICE AND SAFE OPERATION OF THE MAIN PIPELINE FOR TRANSPORTATION Document With requirements SNiPIII-42 . 4.3. Test procedure Test main ammonia pipeline should... Technological equipment and technological pipelinesSNiPIII-42 -80* Trunkpipelines

PREPARED FOR APPROVAL by the Department of Standardization and Technical Standards in Construction of the USSR State Construction Committee (N.A. Shishov), VNIIST (V.I. Prokofiev, V.P. Mentyukov, Candidates of Technical Sciences).

SNiP III-42-80* is a reissue of SNiP III-42-80 with amendments approved by the Decrees of the USSR Gosstroy (Ministry of Construction of Russia) N 272 dated 11/5/1982, N 308 dated 12/28/1982, N 71 dated 12/29/1986 and N 18-79 dated 11/10/1996

1.1. The rules of this chapter must be observed during the construction of new and reconstruction of existing main pipelines and branches from them with a nominal diameter of up to 1400 mm (inclusive) with an excess pressure of the medium of not more than 10 MPa (100 kgf / cm) for transportation:

Oil, oil products, natural and associated, natural and artificial hydrocarbon gases from the areas of their production (from head pumping and compressor stations), production or storage to places of consumption (oil depots, transshipment depots, loading points, gas distribution stations of cities and towns, individual industrial and agricultural enterprises and ports);

Liquefied hydrocarbon gases (fractions C and C and their mixtures), as well as unstable gasoline and unstable condensate and other liquefied hydrocarbons with a saturated vapor pressure of not more than 1.6 MPa (16 kgf/cm) at a temperature of 45 °C from their production areas or production (from head pumping stations) to places of consumption (oil depots, transshipment depots, loading points, industrial enterprises, ports, gas distributing stations and cluster depots);

Marketable products within the head and intermediate gas compressor and oil pumping stations, underground gas storage stations, gas distribution stations, metering points.

1.2*. The rules of this chapter do not apply to the construction of field pipelines, as well as the construction of main pipelines in offshore areas and areas with seismic activity of more than 8 points for underground and more than 6 points for aboveground pipelines. In these cases, the requirements of the relevant departmental regulatory documents (VSN), approved in the prescribed manner, must be observed, and in their absence, special requirements for the production and acceptance of work specified in the project documentation.

1.3. During the construction of main pipelines, in addition to the requirements of this chapter, the requirements of SNiP 3.01.01-85*, SNiP III-4-80*, other building codes and regulations, as well as standards and instructions governing the production and acceptance of certain types of work in the construction of the main pipeline and approved in the prescribed manner.

1.5. The construction of main pipelines must be carried out in-line by mobile mechanized columns or complexes that ensure the continuity of all work in a strict technological sequence.

1.6. Preparatory work and the construction of crossings over natural and artificial obstacles should be carried out by specialized construction and installation units.

1.8. When crossing a main pipeline under construction with underground utilities, construction and installation work is allowed with the permission of the organization operating these communications, and in the presence of its representatives.

1.9. If a construction organization detects underground utilities and structures at the work site that are not listed in the project documentation, measures must be taken to protect them from damage in agreement with the organization operating these communications and structures.

1.10. When opening cable communication lines crossing the pipeline route, the Conditions for the performance of work within the security zones and clearings on the routes of communication and radio lines, approved by the USSR Ministry of Communications, must be observed.

1.11. In the production of construction and installation works, the foremen of the work of construction organizations should carry out operational control of their quality (for all technological processes). Representatives of the customer, as well as representatives of state supervision bodies, have the right to conduct selective quality control of all types of work. The use of materials and products for which there are no certificates, passports and other documents confirming their quality is not allowed.

1.12. During the construction of main pipelines, pipes should be used, mainly insulated in factory or basic conditions. The construction of pipelines from insulated pipes should be carried out according to special technological instructions.

1.13*. Registration of production documentation, including certificates of examination of hidden works, must be carried out in accordance with VSN 012-88, approved by the Minneftegazstroy.

1.14. Materials of the actual position of pipelines (executive survey), drawn up in accordance with the established procedure by construction and installation organizations and the customer, must be transferred to local authorities.

1 area of use

1.1 This set of rules establishes the basic requirements for the production and acceptance of construction and installation works during the construction and reconstruction of the linear part of the main pipelines.

1.2 This set of rules applies to the construction of new and reconstruction of the existing linear part of main pipelines and branches from them with a nominal diameter of up to 1400 mm (inclusive) with an excess pressure of the medium not exceeding 10 MPa for the transportation of the following products:

oil, oil products, natural and associated, natural and artificial hydrocarbon gases;

liquefied hydrocarbon gases (fractions C3 and C4 and their mixtures), as well as unstable gasoline and unstable condensate and other liquefied hydrocarbons with a saturated vapor pressure of not more than 1.6 MPa (16 kgf/cm2) at a temperature of 45 °C.

Does not apply to the construction of field pipelines, as well as the construction of main pipelines in offshore areas.

This set of rules uses normative references to the following documents:

GOST 9.032-74 Unified system of protection against corrosion and aging. Paint coatings. groups, technical requirements and designations

GOST 9.304-87 Unified system of protection against corrosion and aging. Coatings are thermal. General requirements and methods of control

GOST 9.315-91 Unified system of protection against corrosion and aging. Hot aluminum coatings. General requirements and control methods

GOST 9.402-2004 Unified system of protection against corrosion and aging. Paint coatings. Preparation of metal surfaces for painting

GOST 9.602-2005 Unified system of protection against corrosion and aging. Underground structures. General requirements for corrosion protection

GOST 12.1.004-91 SSBT. Fire safety. General requirements

GOST 12.1.007-76 SSBT. Harmful substances. Classification and general safety requirements

GOST 12.3.009-76 SSBT. Loading and unloading works. General safety requirements

GOST 12.3.032-84 SSBT. Electrical works. General safety requirements

GOST 17.2.3.02-78 Nature protection. Atmosphere. Rules for establishing allowable emissions harmful substances industrial enterprises

GOST 17.4.1.02-83 Nature protection. Soils. Classification of chemicals for pollution control

GOST 17.4.3.02-85 Nature protection. Soils. Requirements for the protection of the fertile soil layer during earthworks

GOST 17.4.3.04-85 Nature protection. Soils. General requirements for control and protection against pollution

GOST 17.5.1.01-83 Nature protection. Land reclamation. Terms and Definitions

GOST 17.5.3.05-84 Nature protection. Land reclamation. General grounding requirements

GOST 5686-2012 Soils. Piling Field Test Methods

GOST 6996-66 Welded joints. Methods for determining mechanical properties

GOST 7512-82 Non-destructive testing. Connections are welded. radiographic method

GOST 8695-75 Pipes. Flattening test method

GOST 9466-75 Coated metal electrodes for manual arc welding of steels and surfacing. Classification and general specifications

GOST 14782-86 Non-destructive testing. Connections are welded. Ultrasonic methods

GOST 18442-80 Non-destructive testing. capillary methods. General requirements

GOST 19007-73 Paintwork materials. Method for determining the time and degree of drying

GOST 21105-87 Non-destructive testing. Magnetic particle method

GOST 22761-77 Metals and alloys. Method for measuring Brinell hardness with portable static hardness testers

GOST 23274-84 Mobile buildings (inventory). Electrical installations. General specifications.

GOST 23407-78 Inventory fences construction sites and sites for the production of construction and installation works. Specifications

GOST 23764-79 Gamma flaw detectors. General specifications

GOST 24297-87 Input control of products. Key points

GOST 25113-86 Non-destructive testing. X-ray devices for industrial flaw detection. General specifications

GOST 26887-86 Platforms and ladders for construction and installation works. General specifications

GOST 28012-89 Mobile collapsible scaffolding. Specifications

GOST 28302-89 Gas-thermal protective coatings of zinc and aluminum for metal structures. General requirements for a typical technological process

GOST R 12.4.026-2001 SSBT. Signal colors, safety signs and signal markings. Purpose and rules of application. General technical requirements and characteristics. Test Methods

GOST R 21.1101-2009 SPDS. Basic requirements for design and working documentation

GOST R 51164-98 Main steel pipelines. General requirements for corrosion protection

GOST R 51694-2000 Paint and varnish materials. Coating Thickness Determination

GOST R 52289-2004 Technical means organizations traffic. Rules for the use of road signs, markings, traffic lights, road barriers and guides

GOST R 52290-2004 Technical means of traffic management. Road signs. General technical requirements

GOST R 52568-2006 Steel pipes with protective outer coatings for main gas and oil pipelines. Specifications

SP 4.13130.2009 Fire protection systems. Limiting the spread of fire at protected facilities. Requirements for space-planning and design solutions

SP 14.13330.2011 "SNiP II-7-81* Construction in seismic areas"

SP 25.13330.2012 "SNiP 2.02.04-88 Bases and foundations on permafrost soils"

SP 28.13330.2012 "SNiP 2.03.11-85 Corrosion protection of building structures"

SP 34.13330.2012 "SNiP 2.05.02-85* Highways"

SP 36.13330.2012 "SNiP 2.05.06-85* Main pipelines"

SP 45.13330.2012 "SNiP 3.02.01-87 Earthworks, bases and foundations"

SP 47.13330.2012 “SNiP 11-02-96 Engineering surveys for construction. Basic Provisions»

SP 48.13330.2011 "SNiP 12-01-2004 Organization of construction"

SP 61.13330.2012 "SNiP 41-03-2003 Thermal insulation of equipment and pipelines"

SP 63.13330.2012 “SNiP 52-01-2003 Concrete and reinforced concrete structures. Basic Provisions»

SP 71.13330.2011 "SNiP 3.04.01-87 Insulating and finishing coatings"

SP 72.13330.2011 "SNiP 3.04.03-85 Protection of building structures and facilities against corrosion"

SP 77.13330.2011 "SNiP 3.05.07-85 Automation Systems"

SP 103.13330.2012 "SNiP 2.06.14-85 Protection of mine workings from underground and surface waters"

SP 104.13330.2011 "SNiP 2.06.15-85 Engineering protection of the territory from flooding and flooding"

SP 112.13330.2011 "SNiP 21-01-97* Fire safety of buildings and structures

SP 119.13330.2012 "SNiP 32-01-95 1520 mm gauge railways"

SP 121.13330.2012 "SNiP 32-03-96 Aerodromes"

SP 122.13330.2012 "SNiP 32-04-97 Railway and road tunnels"

SP 126.13330.2012 "SNiP 3.01.03-84 Geodetic works in construction"

Note - When using this set of rules, it is advisable to check the effect of reference standards (sets of rules and / or classifiers) in information system general use - on the official website of the National Authority Russian Federation on standardization on the Internet or according to the annually published information index "National Standards", which is published as of January 1 of the current year, and according to the issues of the monthly published information index "National Standards" for the current year. If the reference standard (document) to which the undated reference is given is replaced, it is recommended to use the current version of this standard (document), taking into account all changes made to this version. If the reference standard (document) to which the dated reference is given is replaced, it is recommended to use the version of this standard (document) with the year of approval (acceptance) indicated above. If, after the approval of this standard, a change is made to the referenced standard (document) to which a dated reference is given, affecting the provision to which the reference is given, then this provision is recommended to be applied without taking into account this change. If the reference standard (document) is canceled without replacement, then the provision in which the link to it is given is recommended to be applied in the part that does not affect this link. Information about the operation of the set of rules can be checked in the Federal Information Fund of Technical Regulations and Standards.

3 Terms and definitions

In this set of rules, the following terms are used with their respective definitions.

3.1 author's supervision: Control of the person who prepared the project documentation for compliance with the requirements of the project documentation during the construction process. [ The federal law dated December 30, 2009 No. 384-FZ, art. 2.3]

3.2 weatherproof paintwork: A paint-and-lacquer-based coating that protects metal surfaces of structures from atmospheric corrosion.

3.3 along-route overhead line; VL: Overhead (overhead with cable inserts) power transmission line designed to provide electrical energy to electrochemical protection equipment and electrical equipment of the linear part of main pipelines.

3.4 customer (technical customer): an individual acting on a professional basis, or entity who are authorized by the developer and on behalf of the developer conclude agreements on the performance of engineering surveys, on the preparation of project documentation, on the construction, reconstruction, overhaul of facilities capital construction, prepare tasks for the performance of these types of work, provide persons performing engineering surveys and (or) preparing project documentation, construction, reconstruction, overhaul of capital construction objects, materials and documents necessary for the performance of these types of work, approve the project documentation, sign the documents necessary to obtain permission to put the capital construction object into operation, perform other functions provided for by this Urban Planning Code. The developer has the right to perform the functions technical customer on one's own; Town Planning Code of the Russian Federation of December 29, 2004 No. 190-FZ, article 1, paragraph 22]

3.5 overlap: An annular butt welded joint connecting the welded sections of the pipeline after they are laid in the design position.

3.6 control and measuring point: A device designed to control the parameters of corrosion threats and the effectiveness of electrochemical protection of underground pipelines and other underground metal structures, as well as for switching components of an electrochemical protection system.

3.7 as-built documentation (ID): Documentation generated by the contractor during the construction or reconstruction of the linear part of the main pipelines and confirming the compliance of the scope and quality of work with the project documentation and the current legislation of the Russian Federation in the field of construction, industrial safety, fire safety, protection environment(including a set of drawings with notes on the compliance of the work performed in kind with these drawings or drawings, with changes made to them design organization on behalf of the customer).

3.8 linear part of the main pipeline: An integral part of the main pipeline, consisting of pipelines (including shut-off and other valves, crossings through natural and artificial obstacles), an electrochemical corrosion protection system, technological communication facilities, other devices and structures, designed to transport oil, natural gas and products of their processing.

3.9 looping: A pipeline laid parallel to the main pipeline and connected to it to increase its capacity. [SP 36.13330, paragraph 3.17]

3.10 marker point: a pre-selected point on the earth's surface above the axis of the pipeline at the location of the transmitter, designed to accurately reference the data of in-line diagnostics to the terrain.

3.11microtunnelling: Automated tunneling with punching of the pipe lining structure, performed without the presence of people in the working.

3.12 impassable tunnel (microtunnel): A tunnel that is not accessible for the passage of people and equipment during the operation of the pipeline.

3.13 special natural conditions: Presence of mountain ranges, water bodies, soils specific in composition and condition, including permafrost, and / or risks of occurrence (development) hazardous processes(phenomena) that may lead to off-design loads and impacts on the main pipeline and/or cause an accident of the main pipeline.

3.14 security zone of the main pipeline: Territory or water area with special conditions of use, established along the main pipeline to ensure its safety. [SP 36.13330, paragraph 3.19]

3.15 pipeline underwater crossing: A section of a pipeline laid across a river or reservoir with a width of more than 10 m in a low water period along the water table and a depth of more than 1.5 m, or a width of 25 m or more along the water table in a low water period, regardless of depth. [SP 36.13330, paragraph 3.16]

3.16 air pipeline transition (beam, cable-stayed): A section of an elevated pipeline laid through natural or artificial barriers.

3.17 contractor: An organization that has, as provided for by the current legislation of the Russian Federation, a certificate of admission to the types of work on the construction and / or reconstruction of trunk pipeline facilities that affect the safety of capital construction facilities, qualified personnel, construction machines and mechanisms, technological equipment, security, control and measurements, as well as a quality control system, and on the basis of an agreement with the customer, construction and reconstruction of the linear part of the main pipelines.

3.18 project of work production: A set of text and graphic documents that establish methods and sequence of execution construction and assembly works, safe, rational ways of high-quality performance technological operations, the composition and degree of detail of which are determined by the specifics and volume of construction and installation work performed.

3.19 anti-corrosion (insulating) coating: Organic (polymeric) coating that protects the metal surfaces of structures from various kinds corrosion, as well as preventing current leakage of cathodic protection.

3.20 passing tunnel: A tunnel accessible for the passage of people and equipment during the operation of the pipeline.

3.21 design documentation (PD): A set of text and graphic design documents that define architectural, functional-technological, constructive and engineering solutions, the composition of which is necessary for conformity assessment decisions taken design assignment, legal requirements, regulatory legal acts, documents in the field of standardization and is sufficient for the development of working documentation for construction. [GOST R 21.1001, section 3.1.2]

3.22 working documentation: A set of text and graphic documents that ensure the implementation of the technical solutions of the capital construction object adopted in the approved design documentation, which are necessary for the production of construction and installation works, the provision of construction with equipment, products and materials and / or the manufacture of building products. [GOST R 21.1001, section 3.1.8]

3.23 building permit: A document confirming the compliance of project documentation with the requirements of the town planning plan land plot or a territory planning project and a territory surveying project (in the case of construction, reconstruction of linear facilities) and giving the developer the right to carry out construction, reconstruction of capital construction facilities. [Urban planning code of the Russian Federation of December 29, 2004 No. 190-FZ, article 51, paragraph 1]

3.24 special welding work: Welding work when connecting pipes of different thicknesses, pipes with pipeline fittings and shut-off and control valves, as well as during the installation of straight tie-ins, branches to the main line, overlaps and tie-in coils.

3.25 construction and installation works (CEW): A set of works performed at the construction and reconstruction site, including civil works and installation technological systems and equipment.

3.26 building control: Quality control of work in the process of construction or reconstruction of the linear part of the main pipelines in order to verify the compliance of the work performed with the design documentation and the working documentation prepared on its basis, with the requirements of regulatory and technical documents. Construction control is carried out as a contractor ( production control), and by the customer, or by an organization engaged by the customer.

3.27 technological instruction for welding: Regulatory document, containing a set of specific operations, grades of welding consumables, equipment for assembling and welding girth welded joints, which determines the technology for making a welded joint in accordance with the requirements of design and regulatory documentation.

3.28 main pipeline: A single production and technological complex, which includes buildings, structures, its linear part, including facilities used to ensure the transportation, storage and (or) transshipment of liquid or gaseous hydrocarbons to road, rail and water transport, measurement of liquid (oil , petroleum products, liquefied hydrocarbon gases, gas condensate, a wide fraction of light hydrocarbons, their mixtures) or gaseous (gas) hydrocarbons that meet the requirements of the legislation of the Russian Federation. [SP 36.13330, paragraph 3.35]

3.29 dirt filters: Devices designed to protect instruments and equipment of oil and product pipelines by cleaning the pumped liquid from mechanical impurities, paraffin-resinous inclusions, and foreign objects;

3.30 control and diagnostic point: A device for measuring the parameters of the electrochemical protection of an object with the ability to control corrosion processes.

3.31 geomodule: Structure with a honeycomb structure, formed from strips of technical fabric (by sewing), filled with technical primer.

USSR STATE COMMITTEE FOR CONSTRUCTION (GOSSTROY USSR)

SNiP III-42-80

MAIN PIPING

Approved by the Decree of the USSR State Committee for Construction of May 16, 1980. № 67

Developed by VNIIST of the Minneftegazstroy with the participation of the institutes Giprotruboprovod of the Minnefteprom and Giprospetsgaz of the Mingazprom.

With the entry into force of the chapter SNiP III-42-80 “Main pipelines”, the chapter SNiP III becomes invalid. D10-72 “Main pipelines. Rules for the production and acceptance of work”.

Editors - eng. N . BUT . Shishov (Gosstroy of the USSR), Ph.D.. Sciences V. AND . Prokofiev, V. P . Mentyukov (VNIIST).

1. GENERAL PROVISIONS

1.1. The rules of this chapter must be observed during the construction of new and reconstruction of existing main pipelines and branches from them with a nominal diameter of up to 1400 mm (inclusive) with an excess pressure of the medium not exceeding 10 MPa (100 kgf / cm 2) for transportation:

oil, oil products, natural and associated, natural and artificial hydrocarbon gases from the areas of their production (from the head pumping pumping and compressor stations), production or storage to the places of consumption (oil depots, transshipment bases, loading points, gas distribution stations cities and towns, individual industrial and agricultural enterprises and ports);

liquefied hydrocarbon gases (fractions C 3 and C 4 and mixtures thereof), as well as unstable gasoline and unstable condensate and other liquefied hydrocarbons with a saturated vapor pressure of not more than 1.6 MPa (16 kgf / cm 2) at a temperature of plus 45 ° C from the areas of their extraction or production (from the head pumping pumping stations) to the places of consumption (oil depots, transshipment depots, loading points, industrial enterprises, ports, gas distributing stations and cluster depots);

marketable products within the head and intermediate gas compressor and oil pumping stations, underground gas storage stations, gas distribution stations, metering points.

1.2. The rules of this chapter do not apply to the construction of field pipelines, as well as the construction of main pipelines in offshore areas and areas with a seismic activity of more than 8 points for underground and more than 6 points for aboveground pipelines. In these cases, the requirements of the relevant departmental regulatory documents (VSN), approved in the prescribed manner, must be observed, and in their absence, special requirements for the production and acceptance of work specified in the project documentation.

1.3. During the construction of main pipelines, in addition to the requirements of this chapter, the requirements of the chapters of SNiP on the organization of construction: production, safety in construction and other chapters of SNiP, standards and instructions governing the production and acceptance of certain types of work in the complex of construction of the main pipeline and approved in the prescribed manner.

1.5. The construction of main pipelines must be carried out in-line by mobile mechanized columns or complexes that ensure the continuity of all work in a strict technological sequence.

1.6. Preparatory work and the construction of crossings over natural and artificial obstacles should be carried out by specialized construction and installation units.

1.7. The width of the land allotment strip for the period of construction of main pipelines is determined by the project in accordance with the Rules for land allotment for main pipelines.

1.9. If underground utilities and structures that are not listed in the design documentation are found at the work site, the construction organization must, in agreement with the organization operating these communications and structures, take measures to protect them from damage.

1.10. When opening cable communication lines crossing the pipeline route, the Conditions for the performance of work within the security zones and glades on the routes of communication and radio lines, approved by the USSR Ministry of Communications, must be observed.

1.11. During the production of construction and installation works, the operational control of their quality (for all technological processes) should be carried out by the producers of the work of construction organizations. Representatives of the customer, as well as representatives of state supervision bodies, have the right to carry out selective quality control of all types of work. The use of materials and products for which there are no certificates, passports and other documents confirming their quality is not allowed.

1.13. Registration of production documentation, including certificates of examination of hidden works, must be carried out in accordance with VSN 012-88 approved by the former Minneftegazstroy.

1.14. Materials of the actual position of pipelines (executive survey), drawn up in accordance with the established procedure by the construction and installation organizations and the customer, must be transferred to the executive committees of the district (city) Soviets of People's Deputies.

2. PREPARATORY WORK

2.1. The customer is obliged to create a geodetic marking base for construction and, at least 10 days before the start of construction and installation work, transfer to the contractor the technical documentation for it and for the points and signs of this base fixed on the pipeline construction route, including: fixing marks turn angles of the track; leading signs of the turn angles of the route in the amount of at least two for each direction of the corner within visibility;

leading signs on straight sections of the route, installed in pairs within sight, but not less than after 1 km;

high-altitude benchmarks installed at least every 5 km along the route, except for those installed at crossings through water barriers (on both banks);

an explanatory note, outlines of the location of signs and their drawings;

catalogs of coordinates and marks of points of the geodetic base.

Permissible root-mean-square errors when constructing a geodetic stakeout: angle measurements± 2"; linear measurements 1/1000; definition of marks ± 50 mm.

2.2. Before the start of construction, the general contracting construction and installation organization must perform the following work on the route:

control the geodetic staking basis with an accuracy of linear measurements of at least 1/500, angular 2 "and leveling between the benchmarks with an accuracy of 50 mm per 1 km of the route. The route is accepted from the customer. according to the act, if the measured line lengths differ from the design ones by no more than than 1/300 of the length, angles of no more than 3 "and mark marks determined from the leveling between the benchmarks - no more than 50 mm;

install additional signs (milestones, poles, etc.) along the axis of the route and along the boundaries of the construction strip;

bring out in nature the horizontal curves of a natural (elastic) bend after 10 m, and an artificial bend - after 2 m;

2.3. Before the start of the main construction and installation work, the general contractor must, if necessary, in addition to the requirements of the head of the SNiP on the organization of construction production, take into account the specific conditions of construction, the following preparatory work on the route:

clear the pipeline right of way from forests, shrubs, stumps and boulders;

remove individual trees and overhanging parts of rocks and stones located outside the right of way, but threatening by their condition to fall into the area of the right of way;

cut steep longitudinal slopes;

to carry out protective anti-landslide and anti-landslide measures;

to carry out measures to ensure the minimum measurement of the soil in the trench strip for the pipeline;

arrange temporary on-site and near-station bases or warehouses for storing materials and equipment;

arrange temporary piers and moorings; prepare temporary production bases and sites for the production of welding, bitumen melting and other works; build temporary settlements that provide the necessary housing, sanitary, cultural and living conditions for workers;

prepare helipads;

create a dispatch communication system;

prepare construction sites for the production of construction and installation works on the construction of pipeline crossings through natural and artificial obstacles and when laying pipelines in tunnels with the necessary temporary amenity and technological premises, structures, roads;

create water metering posts outside the area of work on the arrangement of pipeline crossings through water barriers with the reference of the water metering post by leveling to the high-altitude survey of the pipeline route and the state geodetic network;

remove the fertile layer of the earth and move it to a dump for temporary storage in accordance with clause 13.8 of this chapter.

2.4. The clearing of the route for the period of construction should be carried out within the boundaries of the right of way and in other places established by the project.

In winter, clearing should be carried out in two stages: in the area of the passage of vehicles and the work of construction machines - in advance of the start of the main work, and in the area of digging a trench - immediately before the work of earth-moving machines to a length that ensures their work during the shift.

2.5. Uprooting of stumps in dry sections of the route should be carried out over the entire width of the right of way, and in swampy areas - only on the strip of the future trench of the pipeline and cable. In the rest of the waterway, trees must be cut down at ground level.

2.6. The scope of planning work required for transport purposes and the movement of construction vehicles should be indicated in the construction organization project and specified in the work execution project.

2.7. Temporary roads for the passage of construction and transport vehicles should be arranged as single-lane with widening at the places of turns, turns and sidings (from the side of the pipeline, opposite the false route of the cable communication line). Passages are arranged at a line-of-sight distance, but not more than 600 m.

During the construction of winter roads, it should be mainly limited to compaction of the snow cover with freezing of the ice crust, freezing of the soil surface and maintaining the roadway in good condition.

The type, design, width of roads and turning radii are determined by the construction organization project and are specified in the work execution project.

3. EARTHWORKS

3.1. The dimensions and profiles of the trenches are established by the project depending on the purpose and diameter of the pipelines, soil characteristics, hydrogeological and other conditions.

3.2. The width of the trenches along the bottom must be at least D+300 mm for pipelines up to 700 mm in diameter (where D- conditional diameter of the pipeline) and 1.5 D- for pipelines with a diameter of 700 mm or more, taking into account the following additional requirements:

for pipelines with a diameter of 1200 and 1400 mm when digging trenches with slopes not steeper than 1: 0.5, the width of the trench along the bottom can be reduced to D + 500 mm;

when excavating soil with earthmoving machines, the width of the trenches should be taken equal to the width of the cutting edge of the working body of the machine, adopted by the construction organization project, but not less than that indicated above;

the width of the trenches along the bottom in curved sections from bends of forced bending should be equal to two times the width in relation to the width in straight sections;

3.3. The steepness of the slopes of trenches should be taken in accordance with the head of the SNiP for the production and acceptance of earthworks, and those developed in swamps - according to Table. one.

Table 1

3.4. When digging trenches with bucket-wheel excavators, in order to obtain a more even surface of the bottom of the trenches at the design level and ensure a snug fit of the laid pipeline to the base along the entire length along the axis of the pipeline at a width of at least 3 m, preliminary planning of the strip microrelief should be carried out in accordance with the project.

3.5. The development of trenches in swamps should be carried out with single-shovel excavators with a backhoe on widened or conventional tracks from sledges, draglines or special machines.

3.6, 3.7. exclude.

3.8. In order to prevent deformation of the profile of the dug trench, as well as freezing of the soil heap, the shift rates of insulating-laying and excavation work should be the same.

The technologically necessary gap between the earth-swarming and insulating-laying column must be indicated in the project for the production of works.

The development of trenches in the backlog in soils (with the exception of rocky ones in the summer), as a rule, is prohibited.

Loosening of rocky soils in an explosive way should be carried out before the pipes are taken to the route, and loosening of frozen soils is allowed after laying the pipes on the route.

3.9. When developing trenches with preliminary loosening of rocky soil using a drilling and blasting method, soil sorting should be eliminated by adding soft soil and compacting it.

3.10. Foundations for pipelines in rocky and frozen soils should be leveled with a layer of soft soil with a thickness of at least 10 cm above the protruding parts of the foundation.

3.11. When constructing pipelines with a diameter of 1020 mm or more, the bottom of the trench should be leveled along the entire length of the route: on straight sections every 50 m; on vertical curves of elastic bending after 10 m; on vertical curves of forced bending after 2 m; when constructing pipelines with a diameter of less than 1020 mm only on difficult sections of the route (vertical angles of rotation, sections with rugged terrain), as well as at crossings over railways and roads, ravines, streams, rivers, beams and other obstacles for which individual workers are developed blueprints.

3 . 12 . By the time of laying the pipeline, the bottom of the trench must be leveled in accordance with the project.

Laying the pipeline in a trench that does not comply with the project is prohibited..

3 . 13 . Backfilling of the trench is carried out immediately after the lowering of the pipeline and the installation of ballast weights or anchor devices, if the ballasting of the pipeline is provided for by the project. Places for installation of stop valves, tees of control and measuring points of electrochemical protection are filled up after their installation and welding of cathode leads.

When backfilling the pipeline with soil containing frozen clods, crushed stone, gravel and other inclusions larger than 50 mm in diameter, the insulating coating should be protected from damage by powdering with soft soil to a thickness of 20 cm above the upper generatrix of the pipe or by installing protective coatings provided for by the project.

table 2

Tolerance	Tolerance value (deviation), cm
Half the width of the trench along the bottom in relation to the staking axis	20, - 5
Deviation of marks when planning a lane for the operation of bucket-wheel excavators
Deviation of trench bottom marks from the project:
when excavating soil with earthmoving machines
in the development of soil by drilling and blasting
The thickness of the bed layer of soft soil at the bottom of the trench
The thickness of the layer of powder from soft soil above the pipe (with subsequent backfilling with rocky or frozen soil)
The total thickness of the backfill layer above the pipeline
Embankment height	20, - 5

Note. Conducting post-shrinkage restoration of main pipelines (laying on design marks, restoring design marks, restoring design ballasting, backfilling soil in trenches, restoring embankments, etc.) December 1969 No. 973.

3.14. Soft backfilling of the bottom of the trench and backfilling with soft soil of the pipeline laid in rocky, stony, gravel, dry lumpy and frozen soils can, in agreement with the design organization and the customer, be replaced with continuous reliable protection made of non-rotting, environmentally friendly and non-combustible materials .

3.15. Earthworks during the construction of main pipelines must be carried out in compliance with the tolerances given in Table. 2.

4. ASSEMBLY, WELDING AND QUALITY CONTROL OF WELDED PIPELINE JOINTS

General provisions

4.1. Before assembling and welding pipes, you must:

make a visual inspection of the surface of the pipes (in this case, the pipes should not have unacceptable defects regulated by the technical conditions for the supply of pipes);

clean the internal cavity of the pipes from the soil, dirt, snow that got inside;

straighten or cut deformed ends and damage to the pipe surface;

clean the edges and the inner and outer surfaces of the pipes adjacent to them to a bare metal to a width of at least 10 mm.

In flash butt welding, the end of the pipe and the belt should be additionally cleaned under the contact shoes of the welding machine.

4.2. It is allowed to straighten smooth dents on the ends of pipes with a depth of up to 3.5% of the diameter of the pipes and deformed ends of the pipes with impactless expanding devices. At the same time, on pipes made of steels with a standard tensile strength of up to 539 MPa (55 kgf / mm 2), straightening of dents and deformed pipe ends is allowed at positive temperatures without heating. At negative ambient temperatures, heating by 100-150°C is necessary. On pipes made of steels with a standard tensile strength of 539 MPa (55 kgf / mm 2) and higher - with local heating at 150-200 ° C at any ambient temperature.

Sections and ends of pipes with a dent more than 3.5% of the pipe diameter or with tears must be cut out.

It is allowed to repair by welding nicks and burrs of chamfers up to 5 mm deep.

The ends of pipes with nicks and chamfers with a depth of more than 5 mm should be cut off.

4.3. Assembly of pipes with a diameter of 500 mm or more must be carried out on internal centralizers. Smaller diameter pipes can be assembled using internal or external centralizers. Regardless of the diameter of the pipes, the assembly of overlaps and other joints where the use of internal centralizers is impossible is carried out using external centralizers.

4.4. When assembling pipes with the same standard wall thickness, edge displacement is allowed by up to 20% of the pipe wall thickness, but not more than 3 mm for arc welding methods and not more than 2 mm for flash butt welding.

4.5. Direct connection on the route of pipes of different thicknesses of the same diameter or pipes with parts (tees, transitions, bottoms, bends) is allowed under the following conditions:

if the difference between the wall thicknesses of the joined pipes or pipes with parts (the maximum of which is 12 mm or less) does not exceed 2.5 mm;

if the difference in wall thickness of the pipes or pipes with parts (the maximum of which is more than 12 mm) does not exceed 3 mm.

The connection of pipes or pipes with parts with a greater difference in wall thickness is carried out by welding between the joined pipes or pipes with parts of adapters or inserts of intermediate thickness, the length of which must be at least 250 mm.

With thickness differences up to 1.5 thicknesses, direct assembly and welding of pipes is allowed with special cutting of the edges of the thicker wall of the pipe or part. Structural dimensions of cutting edges and welds must correspond to those indicated in fig. one.

Edge displacement when welding pipes with different walls, measured along the outer surface, should not exceed the tolerances established by the requirements of clause 4.4 of this section.

Welding from the inside of the root of the weld of pipes with a diameter of 1000 mm or more along the entire perimeter of the joint is mandatory, while the welding layer must be cleaned of slag, electrode cinders and slag must be collected and removed from the pipe.

Rice. 1. Structural dimensions of cutting edges and welds of pipes of different thicknesses (up to 1.5 wall thicknesses)

4.6. Each joint must bear the stamp of the welder or team of welders performing the welding. At the joints of pipes made of steel with a standard tensile strength of up to 539 MPa (55 kgf / mm 2), stamps must be applied mechanically or by welding. Joints of pipes made of steel with a standard tensile strength of 539 MPa (55 kgf / mm 2) and higher are marked with indelible paint on the outside of the pipe.

Brands are applied at a distance of 100-150 mm from the joint in the upper semicircle of the pipe.

4.7. Welding of any elements, except for cathode leads, at the locations of transverse annular, spiral and longitudinal factory welds is not allowed. If the project provides for welding of elements to the pipe body, then the distance between the seams of the pipeline and the seam of the welded element must be at least 100 mm.

4.8. Direct connection of pipes with shut-off and distribution valves is allowed provided that the thickness of the welded edge of the fitting pipe does not exceed 1.5 of the wall thickness of the pipe joined to it in the case of special preparation of the edges of the fitting pipe in the factory in accordance with rice. 2.

In all cases when a special cutting of the edges of the fitting pipe is not made in the factory, and also when the thickness of the welded edge of the fitting pipe exceeds 1.5 of the wall thickness of the pipe being joined to it, the connection should be made by welding a special adapter or adapter ring between the pipe being joined and the fitting .

Rice. 2. Preparing wet fittings for fittings by directly connecting them to pipes

4.9. When welding a pipeline into a string, welded joints must be tied to the pickets of the route and recorded in the as-built documentation.

4.10. During a break in operation for more than 2 hours, the ends of the welded section of the pipeline should be closed with inventory plugs to prevent snow, dirt, etc. from getting inside the pipe.

4.11. Circumferential joints of steel main pipelines can be welded by arc welding or flash butt welding.

4.12. It is allowed to perform welding works at air temperature up to minus 50°С.

When the wind is over 10 m/s, as well as during precipitation, it is prohibited to carry out welding work without inventory shelters.

4.13. Installation of pipelines should be carried out only on inventory linings. The use of soil and snow prisms for the installation of the pipeline is not allowed.

4.14. Welders who have passed exams in accordance with the Rules for Certification of Welders of the USSR Gosgortekhnadzor, who have certificates and who have passed the tests regulated by the requirements of paragraphs are allowed to tack and weld main pipelines. 4.16-4.23 of this section.

4.15. Production of welded connecting parts of the pipeline (bends, tees, transitions, etc.) in the field is prohibited.

QUALIFICATION CHECK OF WELDERS

4.16. During the production of welding work, each welder (team or team of welders in the case of welding a joint by a team or team) must (should) weld a tolerance joint for pipes with a diameter of up to 1000 mm

Rice. 3. Scheme of cutting samples for mechanical testing

a- pipes with a diameter up to 400 mm inclusive; b- pipes with a diameter of 400 mm to 1000 mm; in- pipes with a diameter of 1000 mm or more; 1 — sample for tensile testing (GOST 6996-66, type XII or XIII); 2 - sample for bending the root of the seam outward (GOST 6996-66, type XXVII or XXVIII) or on the edge; 3 - sample for bending the weld root inside (GOST 6996-66, type XXVII or XXVIII) or on the edge

or half of the joint for pipes with a diameter of 1000 mm or more under conditions identical to the welding conditions on the route, if:

he (they) for the first time started (and) welding the main pipeline or had (and) a break in his work for more than three months;

pipe welding is carried out from new steel grades or with the use of new welding materials, technology and equipment;

the diameter of pipes for welding has changed (transition from one group of diameters to another - see groups a B C in fig. 3);

the shape of cutting the ends of pipes for welding has been changed.

The tolerance joint is subjected to:

visual inspection and measurement, in which the weld must meet the requirements of paragraphs. 4.26; 4.27 of this section;

radiographic control in accordance with the requirements of clause 4.28 of this section;

mechanical testing of samples cut from a welded joint in accordance with the requirements of clause 4.19 of this section.

4.18. If the joint does not meet the requirements of paragraphs 4.26, 4.27, 4.32 of this section by visual inspection and measurement or during radiographic control, then two other tolerance joints are welded and re-inspected; in the event that unsatisfactory results are obtained during the repeated control at least at one of the joints, the team or an individual welder is recognized as having failed the test.

4.19. Mechanical tests provide for checking specimens for tension and bending, cut from welded joints. The cutting scheme and the required number of samples for various types of mechanical tests must correspond to those indicated in fig. 3 and in table. 3.

Table 3

pipe diameter, we	Number of samples for mechanical testing
	tensile	bending with the location of the piling seam			Total
		outside	inside	on edge
Wall thickness, pipes up to 12.5 mm inclusive
up to 400 mm
Over 400 mm
Pipe wall thickness over 12.5 mm
up to 400 mm
Over 400 mm

Samples for mechanical testing must be prepared in accordance with the requirements of GOST 6996-66 and this chapter.

4.20. The tensile strength of the welded joint, determined on discontinuous samples with the reinforcement removed, must be not less than the standard value of the tensile strength of the pipe metal.

4.21. The arithmetic mean value of the bending angle of samples welded by arc welding methods must be at least 120°, and its minimum value must not be lower than 100°.

4.22. The arithmetic mean value of the bending angle of samples welded by flash butt welding must be at least 70 °, and its minimum value must not be lower than 40 °. When calculating the average value, all angles greater than 110° are taken equal to 110°.

4.23. If the samples cut from the joint have unsatisfactory mechanical properties in accordance with the requirements of paragraphs. 4.20-4.22 of this section, then the tests are carried out on a double number of samples cut from the re-welded joint; in the event that unsatisfactory results are obtained during the repeated test, the team of welders or an individual welder is recognized as having failed the test and must undergo retraining.

Weld control

4.24. Control of welded joints of pipelines is carried out:

systematic operational control carried out during the assembly and welding of pipelines;

visual inspection and measurement of welded joints;

checking of welded seams by non-destructive control methods;

according to the results of mechanical tests of welded joints in accordance with clause 4.29 of this section.

4.25. Operational control should be carried out by the foremen and foremen, and self-control by the performers of the work.

During operational control, the compliance of the work performed with the working drawings, the requirements of this section, state standards and instructions approved in due course.

4.26. The joints made by arc welding are cleaned of slag and subjected to external inspection. At the same time, they should not have cracks, undercuts with a depth of more than 0.5 mm, unacceptable edge displacements, craters II emerging on the surface of the pores.

The reinforcement of the seam should be in the range of 1 to 3 mm in height and have a smooth transition to the base metal-.1 y.

4.27. Joints made by flash butt welding, after removing the internal and external flash, must have a reinforcement no more than 3 mm high. When removing the inner and outer burrs, the pipe wall thickness must not be reduced.

Edge displacement after welding should not exceed 25% of the wall thickness, but not more than 3 mm. Local displacements are allowed by 20% of the joint perimeter, the value of which does not exceed 30% of the wall thickness, but not more than 4 mm.

4.28. Assembly welded joints of pipelines and their sections of all categories, made by arc welding, are subject to control by physical methods in the amount of 100%, of which only welded joints by radiographic method:

pipeline sections of categories B and I in all areas and regardless of diameter;

pipelines with a diameter of 1020-1420 mm and their sections in the regions of Western Siberia and the Far North;

sections of pipelines at crossings through swamps II and III type in all areas;

sections of pipelines at crossings railways and highways I, II and III categories in all districts;

pipelines in the areas of their elevated passages, overlaps, welded-in inserts and fittings.

sections of pipelines indicated in positions 6, 9, 10, 18, 20 and 23 of Table 3 of SNiP 2.05.06-85

In other cases, field welded joints of pipelines and their sections are subject to control for categories II, III and IV radiographic method in the volume, respectively, not less than 25; 10 and 5%, and the remaining welded joints - by ultrasonic or magnetographic method.

Corner welded joints of pipelines are subject to control by the ultrasonic method in the amount of 100%.

4.29. Welded joints of pipelines of categories 1, II, III, IV, made by flash butt welding, are subjected to:

100% control by physical methods according to the registered parameters of the welding process.

mechanical tests in the amount of 1% of the joints in accordance with paragraphs. 4.20, 4.22 of this chapter in order to check the state of the automatic control system for the welding process.

4.30. If the results of mechanical tests of welded joints are unsatisfactory, it is necessary:

stop welding, establish the cause of the unsatisfactory quality of the welded joint;

the entire section of the pipeline, welded from the moment of the last check by the installation organization in the presence of representatives of the customer's technical supervision, is subjected to a force impact on bending with the creation (in the upper II lower parts of each joint) of a stress equal to 0.9 of the standard yield strength.

Work can be continued by this welder on the same installation only after setting up the automatic process control system and after obtaining satisfactory results of an additionally welded and checked tolerance joint in accordance with the requirements of paragraphs. 4.17, 4.19, 4.20, 4.22.

Table 4

	Number of welded joints to be controlled by physical methods, %
pipelines		including
	Total	radiographic	magnetographic or ultrasonic



		At least 25	Rest
		” ” 10
	At least 20	” ” 5
IV (ground and		” ” 10
overhead laying)
corner welds			100 (ultrasonic method)
Notes: 1. Joints of pipelines of overhead crossings, overlaps, welded-in inserts, fittings are controlled in the amount of 100% by radiographic method. 2. Welded joints of pipes and fittings made by supplier plants are not subject to control. 3. On sections of category IV, joints from among the worst in appearance are subject to control.

4.31. In addition to the established norms for the number of welded joints subjected to control by physical methods and mechanical tests, individual welded joints assigned to control by representatives of the customer's technical supervision, the USSR State Gas Supervision and the State Inspectorate for Construction Quality can also be subjected to verification.

4.32. When controlling by physical methods the joints of pipelines made by arc welding methods, welds are considered suitable, in which:

there are no cracks of any depth and extent;

the depth of slag inclusions does not exceed 10% of the pipe wall thickness with their total length not exceeding 1/6 of the joint perimeter;

the largest of the pore sizes as a percentage of the pipe wall thickness does not exceed 20% with a distance between adjacent pores of at least 3 wall thicknesses; 15% with a distance between adjacent pores of at least 2 wall thicknesses; 10% when the distance between adjacent pores is less than 2 wall thicknesses, but not less than 3 times the pore size; 10% with a distance between adjacent pores less than 3 times the pore size in sections with a total length of not more than 30 mm per 500 mm of the seam.

In all cases, the maximum pore size should not exceed 2.7 mm.

Local lack of penetration is allowed at the root of the seam with a depth of up to 10% of the pipe wall thickness, but not more than 1 mm, with a total length of up to 1/6 of the joint perimeter.

In the joints of the pipeline with a diameter of 1000 mm or more in sections made with internal welding, lack of penetration at the root of the seam is not allowed.

The total length of lack of penetration along the edges and between layers in non-rotatable joints of pipes made by automatic arc welding should not exceed 50 mm in a weld section 350 mm long.

The total depth of lack of penetration and slag inclusions located in the same plane should not exceed 10% of the pipe wall thickness, but not more than 1 mm, while the length of the defective section should not exceed 50 mm in a weld section 350 mm long.

4.33. In case of unsatisfactory results of checking by physical methods at least one joint of category IV pipelines, an additional 25% of welded joints from the number of joints made since the previous check should be checked by the same method. In this case, the welder or the team that made the marriage is suspended from work until the check is completed. If, upon re-checking, at least one joint turns out to be of unsatisfactory quality, the welder or the team that allowed the marriage to welding work are not allowed until the re-testing, and the joints welded by them are subjected to 100 radiographic control from the moment of the previous check.

4.34. Correction of defects in joints made by arc welding methods is allowed in the following cases:

if the total length of defective sections does not exceed 1/6 of the joint perimeter;

if the length of the cracks detected in the joint does not exceed 50 mm.

In the presence of cracks with a total length of more than 50 mm, the joints must be removed.

4.35. Correction of defects in joints made by arc welding methods should be carried out in the following ways:

welding from inside the pipe of defective sections at the root of the seam;

surfacing of thread rollers with a height of not more than 3 mm during the repair of external and internal undercuts;

grinding and subsequent welding of seam sections with slag inclusions and pores;

when repairing a joint with a crack up to 50 mm long, two holes are drilled at a distance of at least 30 mm from the edges of the crack on each side, the defective area is completely polished and welded again in several layers;

unacceptable defects detected during external inspection must be eliminated before non-destructive testing is carried out.

4.36. All repaired joint areas must be subjected to external examination, radiographic control and meet the requirements of clause 4.32 of this section. Repeated repair of joints is not allowed.

4.37. The results of checking the joints by physical methods must be drawn up in the form of conclusions. Conclusions, radiographic images, recorded results of ultrasonic flaw detection and ferromagnetic tapes from joints subjected to control are stored in a field testing laboratory (FLT) until the pipeline is put into operation.

Manufacture and installation of pipeline rotation curves

4.38. Turns of the linear part of the pipeline in the vertical and horizontal planes should be performed by elastic bending of the welded pipeline string or installation of curved sections from bent bends.

If in certain sections of the route, in accordance with the project, it is necessary to perform turns of a small radius, which cannot be obtained by bending pipes on cold bending machines and stamp-welded bends made in accordance with the SNiP chapter on main pipeline design standards.

4.39. Performing welded oblique joints in the field is prohibited.

4.40. The radii of elastic bending of the pipeline are set by the project.

The minimum allowable bending radii are taken in accordance with Table. 5.

Table 5

Pipeline diameter, mm		Pipeline diameter, mm	Minimum allowable radii of elastic bending of the pipeline, m
1400	1400
1200	1200
1000	1000

4.41. Elastic bending of a pipeline welded into a thread should be carried out directly when it is laid in a trench dug according to the project.

4.42. Bent bends can be manufactured in basic, factory conditions and directly at the place of laying in the trench from individual pipes or two-pipe sections.

4.43. Only straight-seam and seamless pipes are subject to cold bending.

The unified radii of bent bends are set in accordance with Table. 6.

Table 6

Pipe diameter, mm	Pipe wall thickness, mm	Unified bend radii for cold pipe bending, m
1420	16—20
1220	12—15
1020	10—14
720—820	8—12
	7—10
	6—12
219-377	4—25
Notes: 1. The specified radii refer only to the curved part of the elbow. 2. The deviation of the radius value by ±5% is allowed.

Snip iii 42 80 main pipelines

The system of regulatory documents in the gas industry departmental guiding document rules for the technical operation of main gas pipelines

RULES FOR THE DEVICE AND SAFE OPERATION OF THE MAIN PIPELINE FOR TRANSPORTATION