Steel water and gas pipes. Water and gas pipes (WGP): types, characteristics, application Metal water and gas pipes GOST

GOST 3262-75 is a regulatory document in accordance with which steel water and gas pipes are produced. Using pipes that, unlike plastic products, can be successfully used on open area, carry out installation of pipelines for transporting liquid and gaseous media. These are practically irreplaceable steel pipes in the field of capital and private construction, housing and communal services, agriculture.

VGP steel pipes

General information about VGP steel pipes

Water and gas steel pipes, the parameters of which are determined by GOST 3262-75, belong to products for special purposes, as their name suggests. The differences between their types lie primarily in the method of production. However, no matter what type the steel pipes of the category under consideration belong to, all their parameters are specified by the provisions of a document such as GOST 3262 (75, 80, 85, 91).

So, according to this standard (3262-75, latest edition 91st year), water and gas pipes made by welding can belong to one of the following types:

• non-galvanized;
• galvanized;
• originally made with threads at the ends, which can be obtained by cutting or rolling;
• without thread.

Each type of steel pipe is produced using a specific technology

Areas of application and individual parameters

The main areas of application of water and gas pipes are geometric parameters And specifications which comply with standard 3262-75 - construction and repair. Pipes of this category are used for arranging gas and water communications and heating systems in cottages and multi-apartment buildings, administrative buildings, educational institutions, agricultural, industrial and any other facilities.

So, this type of rolled metal is used in:

• communications of cold and hot water supply;
• heating systems;
• gas pipeline networks.

GOST 3262 (75, 80, 85, 91) assumes that welded pipes VGP can be produced in measured, multiple measured and unmeasured lengths. So, according to this gradation, they have the following dimensions (according to the length of the manufactured products):

• measured – from 4 to 12 m long;
• having a length that is a multiple of the measured value;
• unmeasured with a length within the limits of the measured value.

The standard length of pipes produced according to GOST is limited to 12 meters

Wall size is the criterion by which water and gas pipes are distinguished:

Reinforced VGP pipes are products (sometimes galvanized), the wall thickness of which is increased (accordingly, such products have more weight). They are used for installation of pipelines through which liquid or gaseous media are transported under high pressure.

If the technical characteristics and basic geometric parameters of water and gas pipes are regulated by a regulatory document, then their option design and the cutting length is determined by the customer. Thus, the most popular are pipes whose ends are threaded during the production process. The reason for their high popularity is that they do not require welding to install them.

The use of pipes with ready-made threads significantly reduces the installation time for communications

Threads on VGP pipes can be created during their production:

• rolling (a technology that allows you to obtain threads with the most accurate parameters, while it is assumed that the internal diameter of the pipe will be 10% smaller);
• slicing.

The thread on VGP pipes is cut or rolled at the request of the customer, and it can be either short or long.

When calculating the weight of water and gas pipes, it should be borne in mind that galvanized products weigh 3% more than those made of ferrous metal. The standard also imposes a limitation on deviations in batch weight: they should not exceed 8%.

Technical requirements

An assortment of pipes of each type is formed, which lists their geometric parameters and theoretical weight.

Pipes are manufactured according to size and weight

The steel from which pipes of the VGP category are made must also meet the requirements specified in GOST (380, 1050), while mechanical properties, and chemical composition manufacturing materials are not standardized. Each type of pipe (welded, ferrous metal, galvanized, threaded) has special technical requirements, which should be discussed in more detail.

In accordance with the provisions of GOST, the following requirements are imposed on welded-type pipes of the VGP category.

1. If pipe products are connected using furnace welding technology, then in the area weld their outer diameter can be reduced by half a millimeter. If there is a gentle thickening on the inside of the seam, its size should not exceed 1 mm.
2. If using welding it is necessary to connect water and gas pipes whose wall thickness is more than 5 mm, then their ends must be chamfered at an angle of 35-40 degrees. In this case, the width of the end ring after chamfering should be in the range of 1–3 mm.
3. On the inside of the welded seam of water and gas pipes whose diameter exceeds 20 mm, excess metal must be cut or flattened so that its height does not exceed half a millimeter.
4. The customer can additionally specify the characteristics of products with an internal bore diameter of over 15 mm, produced using hot reduction (drawing) technology and joined by furnace welding. According to such requirements, a flat thickening may be present on the inside of the weld, the height of which is no more than 0.5 mm.

Straight seam welded pipes are produced by folding the sheet and then welding the side edges

Water and gas pipes, the threads at the ends of which are cut or rolled by the manufacturer, must have the following parameters.

1. The threads formed at the ends of water and gas pipes in the factory must correspond to accuracy category “B”. Its characteristics are specified by the provisions of GOST 6357. Thus, the thread must be clean, there cannot be any flaws or burrs on it.
2. At the joints and thread turns there may be blackness, and the height of the thread profile in such places should not be reduced by more than 15%. The customer has the right to set more stringent requirements, according to which the limit for reducing the height of the thread profile can be reduced to 10%.
3. The useful length of the thread (indicated in the assortment and measured without runoff) can be reduced to 15%, but the customer has the right to reduce the value of this deviation to 10%.

Thread requirements according to GOST

1. The zinc layer, which is applied to the entire surface of the water and gas pipe in the factory, must have a thickness of at least 30 microns. It is assumed that in areas with cut threads and at the ends there may be no zinc coating.
2. The zinc film must be applied with high quality; it must not contain bubbles, detachments from the base metal and foreign inclusions (oxides, sintered charge, zinc waste, etc.).
3. GOST allows the presence of flux stains, small deposits of zinc, roughness and marks on the surface of galvanized pipes that are left by elements of lifting devices.
4. If areas not coated with zinc are found on water and gas pipes, they can be re-treated, provided that the total area of ​​such areas does not exceed 0.5% of the total surface area of ​​the product.

VGP galvanized pipes

1. The customer can negotiate with the manufacturer the provision of GOST couplings (8944, 8954, 8965, 8966) - one coupling for each product.
2. On the surface of the pipes, defects such as swelling, sunsets, cracks, oxide film are excluded, and on the ends of the products - delamination.
3. There may be some defects on the surface of water and gas pipes that are caused by the production method (ripples, scratches, dents, traces of stripping). At the same time, such defects should not reduce the pipe wall thickness below the tolerance specified in the product range. A layer of scale may also be present, but it should not interfere with inspection of the product.
4. The ends of water and gas pipes supplied to consumers are cut at right angles. The bevel, if it occurs during pruning, should not exceed 2 degrees. The size of the burrs remaining after trimming should not exceed half a millimeter.

Pipes are checked for compliance with GOST selectively - at least two products from each batch are examined

IN regulatory document also stipulates the control methods to which all pipes of the water and gas category must be subjected:

1. Hydraulic pressure test that pipes must withstand:

Ordinary and light type - 25 kgf/cm2 (2.4 MPa);

Reinforced - 32 kgf/cm2 (3.1 MPa);

Meeting special requirements - 50 kgf/cm2 (4.9 MPa).

• Bend tests carried out on mandrels with a radius of:

– 2.5 outer diameter sizes – products with diameter up to 40 mm;

– 3.5 outer diameter sizes – pipes with DN 50 mm.

• Distribution test for water and gas pipes with remote control:

– 15–50 mm – not less than 7%;

Labeling and storage conditions

By marking water and gas pipes, which must also comply with GOST, you can find out almost all necessary information about the product: geometric dimensions, manufacturing and processing method, quality of material. At the end of the marking, the number of the regulatory document in accordance with which the product was manufactured must be indicated.

Examples of symbols

Special requirements for the packaging of VGP pipes are imposed only if their outer diameter is from 6 to 20 mm. Such pipes, upon specific instructions from the customer, can be packaged in coils.

Depending on the type of water and gas pipes, their storage conditions may be as follows.

• Galvanized products, which are characterized by increased resistance to the formation and development of corrosion, are securely fixed in storage areas and protected from direct moisture.
• Water and gas pipes that are not coated with a protective layer of zinc must be stored in a fixed position in dry rooms with a minimum level of humidity environment.

GOST 3262-75 Steel water and gas pipes: dimensions, characteristics

Steel water and gas pipes technical specifications GOST 3262-75

STATE STANDARD OF THE USSR UNION

STEEL WATER AND GAS PIPES GOST

Specifications 3262-75

Water-supply and gas-supply steel pipes

Date of introduction 01.01.77

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in table. 2.

b) of unmeasured length.

Pipe wall thickness

Weight of 1 m of pipes, kg

Weight of 1 m of pipes, kg

Steel water and gas pipes technical specifications GOST 3262-75 - Document - page

STATE STANDARD OF THE USSR UNION

Specifications Water-supply and gas-supply Specifications

Date of introduction: 01.01.77

This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled cylindrical threads and without threads, used for water and gas pipelines, heating systems, as well as for parts of water and gas pipeline structures.

(Changed edition, Amendment No. 2, 3, 5).

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in Table 2.

1.2. The length of the pipe is made from 4 to 12 m:

a) measured or multiple measured length with an allowance for each cut of 5 mm and a maximum deviation for the entire length plus 10 mm;

b) of unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

(Changed edition, Amendment No. 3, 4).

1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread.

2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm 3 . Galvanized pipes are 3% heavier than non-galvanized ones.

(Changed edition, Amendment No. 1, 3)

1.3. Maximum deviations in pipe sizes should not exceed those indicated in the table. 3.

1. The maximum deviation in the positive direction for wall thickness is limited by the maximum deviations for the mass of the pipes.

2. Pipes of standard manufacturing precision are used for water supply, gas pipelines and heating systems. Pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

1.4. Maximum deviations in the mass of pipes should not exceed + 8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% – for the party;

10% – for a separate pipe.

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm – s conditional passage up to 20 mm inclusive;

1.5 mm – with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

1.7. Pipes with a nominal bore of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

The same, measured length, with thread:

Pipe R-20×2.8 – 4000 GOST 3262-75

The same, with zinc coating, of unmeasured length, with thread:

The same, with zinc coating, custom length, with thread:

Pipe Ts-R-20×2.8 – 4000 GOST 3262-75

For pipes for thread rolling in symbol After the word “pipe” the letter N is indicated.

For pipes with long thread in the symbol, after the word “pipe” the letter D is indicated.

For pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal bore.

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations approved in in the prescribed manner, from steels in accordance with GOST 380-88 and GOST 1050-88 without standardization of mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050-88.

2.2. At the request of the consumer, the ends of pipes to be welded, with a wall thickness of 5 mm or more, must be chamfered at an angle of 35-40° to the end of the pipe. In this case, an end ring 1–3 mm wide should be left.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1; 2.2. (Changed edition, Amendment No. 3, 4).

2.3. At the consumer's request, pipes are equipped with couplings manufactured in accordance with GOST 8944-75, GOST 8954-75, GOST 8965-75 and GOST 8966-75 at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

Individual dents, rippling, scratches, traces of stripping and other defects caused by the production method are allowed if they do not exceed the wall thickness minimum dimensions, as well as a layer of scale that does not interfere with inspection.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more on inner surface pipe seam, the burr must be cut or flattened, and the height of the burr or its traces should not exceed 0.5 mm.

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, manufactured by furnace welding and hot reduction, a gentle thickening with a height of no more than 0.5 mm is allowed on the inner surface of the pipes in the weld area.

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

2.6. The ends of the pipes must be cut at right angles. The bevel of the end is allowed to be no more than 2°. The remaining burrs should not exceed 0.5 mm. When removing burrs, the formation of blunting (rounding) of the ends is allowed. It is allowed to cut pipes in the mill line.

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6-25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307-89.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm 2) – pipes, ordinary and light;

3.1 MPa (32 kgf/cm 2) – reinforced pipes.

At the request of the consumer, the pipes must withstand hydraulic pressure of 4.9 MPa (50 kgf/cm2)

(Changed edition, Amendment No. 2, 3, 5).

2.9. Pipes with a nominal bore up to 40 mm inclusive must withstand the bend test around a mandrel with a radius equal to 2.5 outer diameters, and with a nominal bore of 50 mm - on a mandrel with a radius equal to 3.5 outer diameters.

At the request of the consumer, pipes must withstand the distribution test:

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

(Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050-88.

2.11. Pipe threads must be clean, without flaws or burrs and comply with GOST 6357-81, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10; 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

Threads with torn (for cut) or incomplete (for rolled) threads are allowed on threads, provided that their total length does not exceed 10% of the required thread length, and at the request of the consumer does not exceed 5%.

(Changed edition, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.16. At the request of the consumer, pipe welds are subjected to inspection non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same brand and be accompanied by one quality document in accordance with GOST 10692-80 with an addition for pipes intended for the manufacture of parts for water supply and gas pipeline structures, made of steel in accordance with GOST 1050-88: chemical composition and mechanical properties steel in accordance with the document on the quality of the billet manufacturer.

The batch weight is no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

Allowed to use statistical methods control according to GOST 18242-72 with a normal level. Control plans are established by agreement between the manufacturer and the consumer.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

3.3. To control thread parameters, to test for expansion, flattening, bending, internal burr height, burr residues, right angle and chamfer angle (for pipes with beveled edges), mechanical properties, no more than 1%, but not less than two pipes from the batch are selected, and for pipes manufactured by continuous furnace welding - two pipes per batch.

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

3.5. Each pipe is subjected to hydraulic pressure testing. With 100% quality control of the weld using non-destructive methods, hydraulic pressure testing may not be carried out. At the same time, the ability of the pipes to withstand the test hydraulic pressure is guaranteed.

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places Two pipes from the batch are selected from the inner surface.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, a repeat test is carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out according to GOST 10006-80. Instead of tensile testing, it is allowed to control mechanical properties using non-destructive methods.

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic test carried out according to GOST 3845-75 with exposure under test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728-78. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out according to GOST 8694-75 on a conical mandrel with a cone angle of 6°.

It is permissible to test on a mandrel with a taper angle of 30°.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695-75.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introduced additionally, Amendment No. 3).

4.5. The thickness of the zinc coating on the outer surface and in accessible places on the inner surface is controlled according to GOST 9.301-86 and GOST 9.302-88, as well as with devices of the MT-41NTs, MTZON or Impulse type according to the normative and technical documentation.

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533-88 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026-92 and a set of probes in accordance with TU 2-034-225-87.

(Changed edition, Amendment No. 3, 5).

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160x100 mm, class 3 GOST 3749-77, plate probes set 4 TU 2-034-225-87 or an inclinometer GOST 5378-88. The bevel angle of the chamfer is controlled with a protractor according to GOST 5378-88.

(Changed edition, Amendment No. 3, 6).

4.9. The outer diameter is checked using smooth micrometers in accordance with GOST 6507-90, clamp gauges in accordance with GOST 2216-84 or GOST 18360-93.

The wall thickness, the height of the internal burr and the height of the burrs are measured with a micrometer according to GOST 6507-90 or a wall gauge according to GOST 11358-89 at both ends of the pipe.

The length of the pipes is measured with a tape measure according to GOST 7502-98. Threads are controlled with gauges in accordance with GOST 2533-88.

The mass of a batch of pipes is controlled on scales of no more than 10 tons with a division value of no more than 20 kg.

(Changed edition, Amendment No. 3, 4, 5, 6).

4.10. Weld inspection is carried out using non-destructive methods according to technical documentation.

(Introduced additionally, Amendment No. 4).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage are carried out in accordance with GOST 10692-80 with addition.

5.1.1. Pipe threads must be protected from mechanical damage and corrosion with lubricant according to regulatory and technical documentation.

Sec. 5. (Changed edition, Amendment No. 3).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy

V. I. Struzhok, Ph.D. tech. sciences, V. M. Vorona, Ph.D. tech. sciences, Yu. M. Mironov, Ph.D. tech. nook, A. I. Postolova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Standards dated 09.11.75 No. 2379

3. Inspection frequency 5 years

4. INSTEAD GOST 3262-62

5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

6. Reissue (May 1994) with Amendments No. 1, 2, 3, 4, 5, 6, approved in November 1977, December 1978, January 1987, May 1988, November 1989. , November 1991 (IUS 1-78, 2-79, 4-87, 8-88, 2-90, 2-92)

Pipe supports are used to hold elements of main networks. They are laid during the installation of pipe lines. Made from steel of various strength characteristics and corrosion resistance.

Pipeline support prices add up

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• This section presents expansion membrane tanks, which serve as a reservoir for pumps and accumulators. When you choose a tank for heating system, it is necessary to pay attention to the membrane material, which must be durable and not collapse when exposed to it aggressive environments And high temperature. Should be paid Special attention on operating conditions and the main purpose of the expansion tank in the system. The products presented in this section are certified and manufactured by the most successful companies who specialize in the production of these products.

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Classifier OKPD 2

Legend

File types

, the file consists of unrecognized scanned pages;

Canceled

• 23.40. - the document has been replaced (GOST status -
• 23.40.10 Cast iron and steel pipes *steel pipes and tubes for special purposes, see 77.140.75

Document status: valid, put into effect 01/01/1977 Name on English language: Water-supply and gas-supply steel pipes. Specifications Date of update of information according to the standard: 09/11/2019, at 10:56 (less than 3 months ago) Type of standard: Standards for products (services) Start date of GOST: 1977-01-01 Date of last publication of the document: 2007-05-01

Document codes GOST 3262-75:

OKP code: 138500;138501 KGS code: B62 OKSTU code: 1385

Number of pages: 8

Purpose of GOST 3262-75: This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled cylindrical threads and without threads, used for water and gas pipelines, heating systems, as well as for parts of water and gas pipeline structures

You can download GOST 3262-75 in the following versions:

Date added to file version:

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start of action:

Change No. 1 to GOST 3262-75

Change type: Text change
Change number: 1
Registration number: 2669


Change No. 2 to GOST 3262-75

Change type: Text change
Change number: 2
Registration number: 45


Change No. 3 to GOST 3262-75

Change type: Text change; Title changed
Change number: 3
Registration number: 4456
New value: See title


Change No. 4 to GOST 3262-75

Change type: Text change
Change number: 4
Registration number: 1139
New value: -


Change No. 5 to GOST 3262-75

Change type: Text change
Change number: 5
Registration number: 3347
New value: -


Change No. 6 to GOST 3262-75

Change type: Text change
Change number: 6
Registration number: 1726
New value: -

GOST 3262-75

Group B62

INTERSTATE STANDARD

STEEL WATER AND GAS PIPES

Specifications

Water-supply and gas-supply steel pipes. Specifications

OKP 13 8500, OKP 13 8501

Date of introduction 1977-01-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Ferrous Metallurgy

DEVELOPERS

V.I.Struzhok, Ph.D. tech. sciences; V.M.Vorona, Ph.D. tech. sciences; Yu.M. Mironov, Ph.D. tech. sciences; A.I. Postolova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Standards dated 09.11.75 N 2379

3. Inspection frequency - 5 years

4. INSTEAD GOST 3262-62

5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

________________
* In the territory Russian Federation operates .

6. The validity period was removed by Decree of the State Standard of November 12, 1991 N 1726

7. EDITION with Amendments No. 1, 2, 3, 4, 5, 6, approved in November 1977, December 1978, January 1987, May 1988, November 1989, November 1991 ( IUS 1-78, 2-79, 4-87, 8-88, 2-90, 2-92)

This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled cylindrical threads and without threads, used for water and gas pipelines, heating systems, as well as for parts of water and gas pipeline structures.

(Changed edition, Amendment No. 2, 3, 5).

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in Table 1.

Table 1

Dimensions, mm

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in Table 2.

table 2

Dimensions, mm

Notes:

1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread.

2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm. Galvanized pipes are 3% heavier than non-galvanized pipes.

(Changed edition, Amendment No. 1, 3).

1.2. The length of the pipe is made from 4 to 12 m:

Measured or multiple measured length with an allowance for each cut of 5 mm and a longitudinal deviation for the entire length plus 10 mm;

Unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

1.3. Maximum deviations in pipe sizes should not exceed those indicated in Table 3.

Table 3

Notes:

1. The maximum deviation in the positive direction for wall thickness is limited by the maximum deviations for the mass of the pipes.

2. Pipes of standard manufacturing precision are used for water supply, gas pipelines and heating systems. Pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

1.4. Maximum deviations in the mass of pipes should not exceed +8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% - for the party;

10% - for a separate pipe.

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm - with nominal bore up to 20 mm inclusive;

1.5 mm - with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those specified in Table 4.

Table 4

1.7. Pipes with a nominal diameter of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

Pipe 20x2.8 GOST 3262-75

The same with the coupling:

Pipe M-20x2.8 GOST 3262-75

The same, measured length, with thread:

Pipe P-20x2.8-4000 GOST 3262-75

The same, with zinc coating, of unmeasured length, with thread:

Pipe Ts-R-20x2.8 GOST 3262-75

The same, with zinc coating, custom length, with thread:

Pipe Ts-R-20x2.8-4000 GOST 3262-75

For pipes for rolling threads, the letter N is indicated in the symbol after the word “pipe”.

For pipes with long threads, the letter D is indicated after the word “pipe” in the symbol.

For pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal bore.

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations approved in the prescribed manner, from steels with and without standardization of mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050.

2.2. At the consumer's request, the ends of pipes to be welded with a wall thickness of 5 mm or more must be chamfered at an angle of 35-40° to the end of the pipe. In this case, an end ring 1-3 mm wide should be left.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1, 2.2. (Changed edition, Amendment No. 3, 4).

2.3. At the consumer's request, pipes are equipped with couplings made according to , and , at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

Individual dents, rippling, scratches, traces of stripping and other defects caused by the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a layer of scale that does not interfere with inspection.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more, the burr on the inner surface of the pipe seam must be cut off or flattened, and the height of the burr or its traces should not exceed 0.5 mm.

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, manufactured by furnace welding and hot reduction, a gentle thickening with a height of no more than 0.5 mm is allowed on the inner surface of the pipes in the weld area.

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

2.6. The ends of the pipes must be cut at right angles. The bevel of the end is allowed to be no more than 2°. The remaining burrs should not exceed 0.5 mm. When removing burrs, the formation of blunting (rounding) of the ends is allowed. It is allowed to cut pipes in the mill line.

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6-25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm) - ordinary and light pipes;

3.1 MPa (32 kgf/cm) - reinforced pipes.

At the request of the consumer, the pipes must withstand a hydraulic pressure of 4.9 MPa (50 kgf/cm).

2.9. Pipes with a nominal bore up to 40 mm inclusive must withstand the bend test around a mandrel with a radius equal to 2.5 outer diameters, and with a nominal bore of 50 mm - on a mandrel with a radius equal to 3.5 outer diameters.

At the request of the consumer, pipes must withstand the distribution test:

For pipes with a nominal bore from 15 to 50 mm - no less than 7%;

For pipes with a nominal bore of 65 mm or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between flattened surfaces equal to 2/3 of the outer diameter of the pipes.

2.8, 2.9. (Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050.

2.11. Pipe threads must be clean, without flaws or burrs and correspond to accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10, 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

Threads with torn (for cut) or incomplete (for rolled) threads are allowed on threads, provided that their total length does not exceed 10% of the required thread length, and at the request of the consumer does not exceed 5%.

2.13. On a thread, it is allowed to reduce the useful length of the thread (without run-out) by up to 15% compared to that indicated in Table 4, and at the request of the consumer - up to 10%.

2.12, 2.13. (Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.15. (Deleted, Amendment No. 3).

2.16. At the request of the consumer, pipe welds are subjected to testing using non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same grade of steel and be accompanied by one quality document in accordance with the addendum for pipes intended for the manufacture of parts for water supply and gas structures, made of steel according to; chemical composition and mechanical properties of steel - in accordance with the document on the quality of the manufacturer of the workpiece.

Batch weight - no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

It is allowed to use statistical control methods at a normal level. Control plans are established by agreement between the manufacturer and the consumer.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

3.3. To control the parameters of the thread, to test for expansion, flattening, bending, the height of the internal burr, the remains of burrs, the right angle and the chamfer angle (for pipes with beveled edges), mechanical properties, no more than 1%, but not less than two pipes from the batch are selected, and for pipes manufactured by continuous furnace welding - two pipes per batch.

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

3.5. Each pipe is subjected to hydraulic pressure testing. With 100% quality control of the weld using non-destructive methods, hydraulic pressure testing may not be carried out. At the same time, the ability of the pipes to withstand the test hydraulic pressure is guaranteed.

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places on the inner surface, two pipes from the batch are selected.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out in accordance with GOST 10006. Instead of the tensile test, it is allowed to control the mechanical properties by non-destructive methods.

4.2. Inspection of the pipe surface is carried out visually.

4.3. Hydraulic testing is carried out with exposure under test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out on a conical mandrel with a taper angle of 6°.

Testing on a mandrel with a taper angle of 30° is allowed.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods in accordance with regulatory documentation.

(Introduced additionally, Amendment No. 3).

4.5. The thickness of the zinc coating on the outer surface and in accessible places on the inner surface is controlled by and, as well as by instruments of the MT-41NTs, MTZON or "Impulse" type according to regulatory documentation.

4.6. The threads are checked using threaded ring gauges (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge and a set of probes according to ND.

(Changed edition, Amendment No. 3, 5).

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160x100 mm class 3 according to , plate probes set 4 according to ND or an inclinometer according to GOST 5378. The bevel angle of the chamfer is controlled with an inclinometer according to GOST 5378.

(Changed edition, Amendment No. 3, 6).

4.9. Control of the outer diameter is carried out with smooth micrometers according to, clamp gauges according to or GOST 18360.

The wall thickness, the height of the internal burr and the height of the burrs are measured with a micrometer or a wall gauge at both ends of the pipe.

The length of the pipes is measured with a tape measure in accordance with GOST 7502. The threads are controlled with gauges in accordance with GOST 2533.

The mass of a batch of pipes is controlled on scales of no more than 10 tons with a division value of no more than 20 kg.

(Changed edition, Amendment No. 3, 4, 5, 6).

4.10. Weld inspection is carried out using non-destructive methods according to technical documentation.

(Introduced additionally, Amendment No. 4).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage are carried out according to the addition.

5.1.1. Pipe threads must be protected from mechanical damage and corrosion by lubricant according to regulatory documentation.

Section 5. (Changed edition, Amendment No. 3).

The text of the document is verified according to:
official publication
Metal pipes and connecting parts for them.
Part 3. Welded pipes. Profile pipes: Sat. GOST. -
M.: IPK Standards Publishing House, 2001

INTERSTATE STANDARD

STEEL PIPES
WATER AND GAS

TECHNICAL CONDITIONS

Date of introduction 01/01/77

This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled cylindrical threads and without threads, used for water and gas pipelines, heating systems, as well as for parts of water and gas pipeline structures.

1. ASSORTMENT

1.1. Pipes are manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, light series pipes intended for thread rolling are manufactured according to the dimensions and weight given in table. 2.

1.2. The length of the pipe is made from 4 to 12 m:

a) measured or multiple measured length with an allowance for each cut of 5 mm and a maximum deviation for the entire length plus 10 mm;

b) of unmeasured length.

By agreement between the manufacturer and the consumer, up to 5% of pipes with a length of 1.5 to 4 m are allowed in a batch of unmeasured pipes.

Table 1

table 2

1.3. Maximum deviations in pipe sizes should not exceed those indicated in the table. 3.

Table 3

Pipes with increased manufacturing precision are used for parts of water and gas pipeline structures.

1.4. Maximum deviations in the mass of pipes should not exceed +8%.

At the request of the consumer, maximum deviations in mass should not exceed:

7.5% - for the party;

(Changed edition, Amendment No. 2, 5).

1.5. The curvature of pipes per 1 m length should not exceed:

2 mm - with nominal bore up to 20 mm inclusive;

1.5 mm - with a nominal bore over 20 mm.

10% - for a separate pipe.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

short

1.7. Pipes with a nominal bore of 6, 8, 10, 15 and 20 mm are wound into coils at the consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

The same with the coupling:

The same, measured length, with thread:

The same, with zinc coating, of unmeasured length, with thread:

The same, with zinc coating, custom length, with thread:

For pipes with long threads, the letter D is indicated after the word “pipe” in the symbol.

For pipes with increased manufacturing precision, the letter P is indicated in the symbol after the size of the nominal bore.

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to technological regulations approved in the prescribed manner, from steels in accordance with GOST 380 and GOST 1050 without standardization of mechanical properties and chemical composition.

Pipes for parts of water supply and gas pipeline structures are made of steel in accordance with GOST 1050.

2.2. At the request of the consumer, the ends of pipes to be welded, with a wall thickness of 5 mm or more, must be chamfered at an angle of 35 - 40° to the end of the pipe. In this case, an end ring 1 - 3 mm wide should be left.

At the request of the consumer, on ordinary and reinforced pipes with a nominal bore of more than 10 mm, threads are applied to both ends of the pipe.

2.1; 2.2.

2.3. At the request of the consumer, pipes are equipped with couplings manufactured in accordance with GOST 8944, GOST 8954, GOST 8965 and GOST 8966 at the rate of one coupling for each pipe.

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

Individual dents, rippling, scratches, traces of stripping and other defects caused by the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a layer of scale that does not interfere with inspection.

On pipes made by furnace welding, it is allowed to reduce the outer diameter to 0.5 mm at the seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

(Changed edition, Amendment No. 3, 4).

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more, the burr on the inner surface of the pipe seam must be cut off or flattened, and the height of the burr or its traces should not exceed 0.5 mm.

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, manufactured by furnace welding and hot reduction, a gentle thickening with a height of no more than 0.5 mm is allowed on the inner surface of the pipes in the weld area.

(Changed edition, Amendment No. 2, 3, 4, 5, 6).

2.6. The ends of the pipes must be cut at right angles. The bevel of the end is allowed to be no more than 2°. The remaining burrs should not exceed 0.5 mm. When removing burrs, the formation of blunting (rounding) of the ends is allowed. It is allowed to cut pipes in the mill line.

By agreement between the manufacturer and the consumer, burrs up to 1 mm are allowed on pipes with a nominal bore of 6 - 25 mm, manufactured by furnace welding.

(Changed edition, Amendment No. 4, 6).

2.7. Galvanized pipes must have a continuous zinc coating over the entire surface with a thickness of at least 30 microns. The absence of zinc coating on the ends and threads of pipes is allowed.

On the surface of galvanized pipes, bubbles and foreign inclusions (hardzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux spots and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

It is allowed to correct individual non-galvanized areas on 0.5% of the outer surface of the pipe in accordance with GOST 9.307.

(Changed edition, Amendment No. 3, 4).

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf/cm 2) - pipes, ordinary and light;

3.1 MPa (32 kgf/cm 2) - reinforced pipes.

At the request of the consumer, the pipes must withstand hydraulic pressure of 4.9 MPa (50 kgf/cm2)

(Changed edition, Amendment No. 2, 3, 5).

2.9. Pipes with a nominal bore up to 40 mm inclusive must withstand the bend test around a mandrel with a radius equal to 2.5 outer diameters, and with a nominal bore of 50 mm - on a mandrel with a radius equal to 3.5 outer diameters.

At the request of the consumer, pipes must withstand the distribution test:

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

At the request of the consumer, pipes must withstand the flattening test to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

(Changed edition, Amendment No. 2, 3, 5).

2.10. At the request of the consumer, the mechanical properties of pipes for parts of water supply and gas pipeline structures must comply with GOST 1050.

2.11. Pipe threads must be clean, without flaws or burrs and comply with GOST 6357, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.10; 2.11. (Changed edition, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction in the normal height of the thread profile does not exceed 15%, and at the request of the consumer does not exceed 10%.

Threads with torn (for cut) or incomplete (for rolled) threads are allowed on threads, provided that their total length does not exceed 10% of the required thread length, and at the request of the consumer does not exceed 5%.

(Changed edition, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

(Changed edition, Amendment No. 2, 3, 5).

2.14. Threading on galvanized pipes is carried out after galvanizing.

2.15. (Deleted, Amendment No. 3).

2.16. At the request of the consumer, pipe welds are subjected to testing using non-destructive methods.

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same grade and be accompanied by one quality document in accordance with GOST 10692 with an addition for pipes intended for the manufacture of parts for water supply and gas pipeline structures, made of steel in accordance with GOST 1050: chemical composition and mechanical properties of steel in accordance with document on the quality of the workpiece manufacturer.

The batch weight is no more than 60 tons.

(Changed edition, Amendment No. 3, 4).

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

It is allowed to use statistical control methods in accordance with GOST 18242 * with a normal level. Control plans are established by agreement between the manufacturer and the consumer.

* GOST R 50779.71-99 is in force on the territory of the Russian Federation.

The outer diameter of the pipes is checked at a distance of at least 15 mm from the end of the pipe.

(Changed edition, Amendment No. 3, 4, 5).

3.3. To control thread parameters, to test for expansion, flattening, bending, internal burr height, burr residues, right angle and chamfer angle (for pipes with beveled edges), mechanical properties, no more than 1%, but not less than two pipes from the batch are selected, and for pipes manufactured by continuous furnace welding - two pipes per batch.

(Changed edition, Amendment No. 3, 4).

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

3.5. Each pipe is subjected to hydraulic pressure testing. With 100% quality control of the weld using non-destructive methods, hydraulic pressure testing may not be carried out. At the same time, the ability of the pipes to withstand the test hydraulic pressure is guaranteed.

(Changed edition, Amendment No. 6).

3.6. To check the thickness of the zinc coating on the outer surface and in accessible places on the inner surface, two pipes from the batch are selected.

(Changed edition, Amendment No. 2).

3.7. If unsatisfactory test results are obtained for at least one of the indicators, a repeat test is carried out on a double sample.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test.

The tensile test is carried out according to GOST 10006. Instead of tensile testing, it is allowed to control mechanical properties using non-destructive methods.

(Changed edition, Amendment No. 3, 6).

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845 with exposure to test pressure for at least 5 s.

4.4. The bend test is carried out according to GOST 3728. Galvanized pipes are tested before coating.

(Changed edition, Amendment No. 3).

4.4a. The expansion test is carried out according to GOST 8694 on a conical mandrel with a cone angle of 6°.

Testing on a mandrel with a taper angle of 30° is allowed.

(Changed edition, Amendment No. 3, 4).

4.4b. The flattening test is carried out according to GOST 8695.

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introducedadditionally, Rev. No. 3).

4.5. The thickness of the zinc coating on the outer surface and in accessible places on the inner surface is controlled according to GOST 9.301 and GOST 9.302, as well as with devices of the MT-41NTs, MTZON or Impulse type according to the normative and technical documentation.

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

(Changed edition, Amendment No. 3, 4).

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026 and a set of probes in accordance with NTD.

(Changed edition, Amendment No. 3, 5).

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160´100 mm class 3 GOST 3749, plate probes set 4 according to NTD or an inclinometer

GOST 3262-75 is a regulatory document in accordance with which steel water and gas pipes are produced. With the help of such pipes, which, unlike plastic products, can be successfully used in open areas, pipelines are installed for transporting liquid and gaseous media. Such steel pipes are practically irreplaceable in the field of capital and private construction, housing and communal services, and agriculture.

You can familiarize yourself with the GOST requirements for steel water and gas pipes by downloading the document in pdf format follow the link below.

General information about VGP steel pipes

Water and gas steel pipes, the parameters of which are determined by GOST 3262-75, belong to products for special purposes, as their name suggests. The differences between their types lie primarily in the method of production. However, no matter what type the steel pipes of the category under consideration belong to, all their parameters are specified by the provisions of a document such as GOST 3262 (75, 80, 85, 91).

So, according to this standard (3262-75, latest edition 91st year), water and gas pipes made by welding can belong to one of the following types:

• non-galvanized;
• galvanized;
• originally made with threads at the ends, which can be obtained by cutting or rolling;
• without thread.

Areas of application and individual parameters

The main areas of application of water and gas pipes, the geometric parameters and technical characteristics of which comply with standard 3262-75, are construction and repair. Pipes of this category are used for arranging gas and water communications and heating systems in cottages and multi-apartment buildings, administrative buildings, educational institutions, agricultural, industrial and any other facilities.

So, this type of rolled metal is used in:

• communications of cold and hot water supply;
• heating systems;
• gas pipeline networks.

GOST 3262 (75, 80, 85, 91) assumes that welded ones can be produced in regular, multiple and unmeasured lengths. So, according to this gradation, they have the following dimensions (according to the length of the manufactured products):

• measured – from 4 to 12 m long;
• having a length that is a multiple of the measured value;
• unmeasured with a length within the limits of the measured value.

Wall size is the criterion by which water and gas pipes are distinguished:

• ordinary;
• lungs;
• reinforced.

Reinforced VGP pipes are products (sometimes galvanized), the wall thickness of which is increased (accordingly, such products have more weight). They are used for installation of pipelines through which liquid or gaseous media are transported under high pressure.

If the technical characteristics and basic geometric parameters of water and gas pipes are regulated by a regulatory document, then the design option and cutting length are determined by the customer. Thus, the most popular are pipes whose ends are threaded during the production process. The reason for their high popularity is that they do not require welding to install them.

Threads on VGP pipes can be created during their production:

• rolling (a technology that allows you to obtain threads with the most accurate parameters, while it is assumed that the internal diameter of the pipe will be 10% smaller);
• slicing.

The thread on VGP pipes is cut or rolled at the request of the customer, and it can be either short or long.

When calculating the weight of water and gas pipes, it should be borne in mind that galvanized products weigh 3% more than those made of ferrous metal. The standard also imposes a limitation on deviations in batch weight: they should not exceed 8%.

Technical requirements

An assortment of pipes of each type is formed, which lists their geometric parameters and theoretical weight.

The steel from which pipes of the VGP category are made must also meet the requirements specified in GOST (380, 1050), while the mechanical properties, as well as the chemical composition of the manufacturing material, are not standardized. Each type of pipe (welded, ferrous metal, galvanized, threaded) has special technical requirements, which should be discussed in more detail.

In accordance with the provisions of GOST, the following requirements are imposed on welded-type pipes of the VGP category.

1. If tubular products are connected using furnace welding technology, then in the area of ​​the weld their outer diameter can be reduced by half a millimeter. If there is a gentle thickening on the inside of the seam, its size should not exceed 1 mm.
2. If using welding it is necessary to connect water and gas pipes whose wall thickness is more than 5 mm, then their ends must be chamfered at an angle of 35-40 degrees. In this case, the width of the end ring after chamfering should be in the range of 1–3 mm.
3. On the inside of the welded seam of water and gas pipes whose diameter exceeds 20 mm, excess metal must be cut or flattened so that its height does not exceed half a millimeter.
4. The customer can additionally specify the characteristics of products with an internal bore diameter of over 15 mm, produced using hot reduction (drawing) technology and joined by furnace welding. According to such requirements, a flat thickening may be present on the inside of the weld, the height of which is no more than 0.5 mm.

Threaded

Water and gas pipes, the threads at the ends of which are cut or rolled by the manufacturer, must have the following parameters.

1. The threads formed at the ends of water and gas pipes in the factory must correspond to accuracy category “B”. Its characteristics are specified by the provisions of GOST 6357. Thus, the thread must be clean, there cannot be any flaws or burrs on it.
2. At the joints and thread turns there may be blackness, and the height of the thread profile in such places should not be reduced by more than 15%. The customer has the right to set more stringent requirements, according to which the limit for reducing the height of the thread profile can be reduced to 10%.
3. The useful length of the thread (indicated in the assortment and measured without runoff) can be reduced to 15%, but the customer has the right to reduce the value of this deviation to 10%.

1. The zinc layer, which is applied to the entire surface of the water and gas pipe in the factory, must have a thickness of at least 30 microns. It is assumed that in areas with cut threads and at the ends there may be no zinc coating.
2. The zinc film must be applied with high quality; it must not contain bubbles, detachments from the base metal and foreign inclusions (oxides, sintered charge, zinc waste, etc.).
3. GOST allows the presence of flux stains, small deposits of zinc, roughness and marks on the surface of galvanized pipes that are left by elements of lifting devices.
4. If areas not coated with zinc are found on water and gas pipes, they can be re-treated, provided that the total area of ​​such areas does not exceed 0.5% of the total surface area of ​​the product.

1. The customer can negotiate with the manufacturer the provision of GOST couplings (8944, 8954, 8965, 8966) - one coupling for each product.
2. On the surface of the pipes, defects such as swelling, sunsets, cracks, oxide film are excluded, and on the ends of the products - delamination.
3. There may be some defects on the surface of water and gas pipes that are caused by the production method (ripples, scratches, dents, traces of stripping). At the same time, such defects should not reduce the pipe wall thickness below the tolerance specified in the product range. A layer of scale may also be present, but it should not interfere with inspection of the product.
4. The ends of water and gas pipes supplied to consumers are cut at right angles. The bevel, if it occurs during pruning, should not exceed 2 degrees. The size of the burrs remaining after trimming should not exceed half a millimeter.

The regulatory document also stipulates the control methods to which all pipes of the water and gas category must be subjected:

1. Hydraulic pressure test that pipes must withstand:
   - ordinary and light type - 25 kgf/cm2 (2.4 MPa);
   - reinforced - 32 kgf/cm2 (3.1 MPa);
   - meeting special requirements - 50 kgf/cm2 (4.9 MPa).
2. Bend tests carried out on mandrels with a radius of:
   – 2.5 outer diameter sizes – products with diameter up to 40 mm;
   – 3.5 outer diameter sizes – pipes with DN 50 mm.
3. Distribution test for water and gas pipes with remote control:
   – 15–50 mm – not less than 7%;
   – more than 65 mm – not less than 4%.