GOST 11068-81 spreads on electric welded pipes made of corrosion-resistant (stainless) steels, intended for the manufacture of pipelines and various structures.

• GOST 2216-84 Smooth adjustable clamp gauges. Specifications
• GOST 3728-78 Pipes. Bend test method
• GOST 3845-75 Metal pipes. Hydraulic pressure test method
• GOST 5632-72 High-alloy steels and corrosion-resistant, heat-resistant and heat-resistant alloys. Stamps
• GOST 5639-82 Steels and alloys. Methods for identifying and determining grain size
• GOST 6032-89 Corrosion-resistant steels and alloys. Test methods for resistance to intergranular corrosion
• GOST 6507-90 Micrometers. Specifications
• GOST 7502-89 Metal measuring tapes. Specifications
• GOST 7565-81 Cast iron, steel and alloys. Sampling method for determining chemical composition
• GOST 8026-92 Calibration rulers. Specifications
• GOST 8693-80 Metal pipes. Board test method
• GOST 8694-75 Pipes. Dispense test method
• GOST 8695-75 Pipes. Flattening test method
• GOST 10006-80 Metal pipes. Tensile test method
• GOST 10692-80 Steel, cast iron pipes and connecting parts for them. Reception, labeling, packaging, transportation and storage
• GOST 11358-89 Indicator thickness and wall gauges with division values ​​of 0.01 and 0.1 mm. Specifications
• GOST 12344-88 Alloy and high-alloy steels. Carbon determination methods
• GOST 12346-78 Alloy and high-alloy steels. Methods for determining silicon
• GOST 12347-77 Alloy and high-alloy steels. Phosphorus determination methods
• GOST 12348-78 Alloy and high-alloy steels. Methods for determining manganese
• GOST 12349-83 Alloy and high-alloy steels. Methods for determining tungsten
• GOST 12350-78 Alloy and high-alloy steels. Methods for determining chromium
• GOST 12351-81 Alloy and high-alloy steels. Methods for determining vanadium
• GOST 12352-81 Alloy and high-alloy steels. Methods for determining nickel
• GOST 12353-78 Alloy and high-alloy steels. Methods for determining cobalt
• GOST 12354-81 Alloy and high-alloy steels. Methods for determining molybdenum
• GOST 12355-78 Alloy and high-alloy steels. Methods for determining copper
• GOST 12356-81 Alloy and high-alloy steels. Methods for determining titanium
• GOST 12365-84 Alloy and high-alloy steels. Methods for determining zirconium
• GOST 28473-90 Cast iron, steel, ferroalloys, chrome, manganese metal. General requirements to methods of analysis
• GOST 22536.0-87 Carbon steel and unalloyed cast iron. General requirements for analysis methods
• GOST 22536.14-88 Carbon steel and unalloyed cast iron. Method for determination of zirconium

CONNECTING PARTS TO THEM

STATE STANDARDS OF THE USSR UNION

METAL PIPES AND CONNECTING PARTS FOR THEM

Official publication

PUBLISHING HOUSE OF STANDARDS 1981

UDC S69.14.462.3.006.354

FROM THE PUBLISHER

The collection “Metal pipes and connecting parts for them”, part 2 contains standards approved before October 1, 1980.

All changes adopted before specified period. There is a * sign next to the number of the standard to which the change has been made.

Current information on newly approved and revised standards, as well as changes adopted to them, is published in the monthly information index “ State standards THE USSR".

© Standards Publishing House, 1981

Group B62

STATE STANDARD OF THE USSR UNION

STAINLESS STEEL ELECTRIC WELDED PIPES

Electrically welded stainless steel tubes

from 01/01/1966 to 01/01/1962

Approved by the State Committee of Standards, Measures and Measuring Instruments of the USSR on October 26, 1964. Validity period established

Failure to comply with the standard is punishable by law

This standard applies to electric-welded stainless steel pipes used for various structures and pipelines.

I. ASSORTMENT

1. The dimensions of the pipes must correspond to those indicated in the table. 1.

2. According to the length of the pipe, the following must be supplied:

a) unmeasured length from 1.5 to 8 m; by agreement of the parties, it is possible to supply pipes longer than 8 m;

b) measured length from 5 to 8 m;

c) a length that is a multiple of the measured length within the unmeasured length with an allowance for each cut of 5 mm (unless otherwise specified in the order) and permissible deviations along the entire length + 15 mm.

3. In each batch of pipes of unmeasured length, no more than 5% of pipes up to 1.5 m long, but not less than 0.5 m, are allowed.

4. Permissible deviations in the outer diameter and wall thickness of the pipes should not exceed those indicated in the table. 2.

5. The curvature of the pipes should not exceed 1.5 mm per 1 m.

Official publication Reproduction prohibited

where D,i is nominal outside diameter pipes, mm; s - pipe wall thickness, mm; y is the relative mass of the metal depending on the steel grade (see Table 4).

3. Pipe sizes limited by the contour are supplied after the start-up of new equipment.

table 2

Pipe dimensions, mm

Outer diameter: ±0.3 mm ±0.4 mm ±1.0%

Up to Yu From 10 to 30 Over. thirty

Wall thickness: ±0.20 mm ±0.25 mm ±10%

Up to 2 From 2 to 3 Over 3

Permissible deviation

Note. For pipes with a wall thickness of 1.5 mm with the state Quality Mark, the maximum deviations in wall thickness should not exceed ±0.15 mm.

6. Ovality and variation in wall thickness of pipes should not take its dimensions beyond the permissible deviations in outer diameter and wall thickness.

Examples symbols pipes with an outer diameter of 25 mm and a wall thickness of 2 mm.

Unmeasured lengths made of steel grade 12Х18Н10Т:

pp. 5, 6. (Changed edition - “Informational Index of Standards” No. 2, 1978).

II. TECHNICAL REQUIREMENTS

7. Pipes must be made of steel grades specified in table. 4, with a chemical composition in accordance with GOST 5632-72. The chemical composition of steel grades 00Х18Н10Т and 0Х23Н28М2Т must correspond to that indicated in the table. 3.

(Changed edition - “Informational Index of Standards” No. 2, 1978).

8. The surface of the pipes must be clean, smooth, without scale, traces of over-etching, lack of fusion, pores, cracks, caps, flaws and deep scratches.

Small scratches, dents, scratches, minor nicks and traces of cleaning defects are allowed provided that they do not take the wall thickness and outer diameter beyond the permissible deviations.

9. On the inner surface of the pipes (along the seam), the height of the flash should not exceed 0.7 mm with a smooth transition to the pipe walls.

At the customer's request, pipes with a nominal internal diameter of 20 mm or more are supplied without internal flash. In this case, burr marks with a height of no more than 0.3 mm are allowed.

10. The ends of the pipes must be cut at right angles and cleared of burrs.

11. Pipes are supplied in a heat-treated state. At the customer's request, specified in the order, pipes can be supplied without heat treatment. The mechanical properties of pipes must correspond to those indicated in the table. 4.

12. For chemical engineering, chemical industry, at the request of consumers for other industries, all heat-treated pipes must withstand the intercrystalline corrosion test.

13. At the request of the consumer, pipes must be subjected to one or two types of tests:

a) flattening - for heat-treated pipes by an amount R equal to 7 g of outer diameter; for pipes without thermal

metal processing - by an amount R equal to 2/3 of the outer diameter;

for heat-treated pipes with the state Quality Mark, the value I should be equal to 73 of the outer diameter;

b) expansion on a mandrel with a taper of 7“ - for heat-treated pipes until the outer diameter increases by 8%;

for heat-treated pipes with the state Quality Mark, the expansion test must be carried out until the outer diameter increases by 10%;

c) beading at an angle of 90° - for heat-treated pipes with an outer diameter of 25 mm or more. The width of the bead, measured from the inner surface of the pipe, must be at least 1.5 times the thickness of the pipe wall.

Note. Pipes tested for beading are not subject to expansion testing.

d) bend; bend radii must correspond to the series established in GOST 17380-77; their value is accepted by agreement of the parties.

(Changed edition - “Informative Index of Standards” No. 2 1978).

14. At the consumer’s request, heat-treated pipes made of steel grade 12Х18Н10Т are supplied with a guaranteed

grain size within 3-7 points. In this case, the pipes are not subjected to inspection for intergranular corrosion.

15. Pipes must withstand the hydraulic pressure test P = 5.9 MPa (60 kgf/cm2), but not more than calculated by the formula

where 5 M is the minimum pipe wall thickness, mm;

R - permissible stress, MPa (kgf/mm 2), equal to 40% of the tensile strength for steel of a given grade;

Du - internal diameter of the pipe, mm.

At the request of the consumer, the test hydraulic pressure P can be increased, but should not exceed that calculated by the formula.

Hydraulic pressure testing can be done randomly with 100% quality control weld by physical methods without destroying the pipe, provided that the tightness of all supplied pipes is guaranteed.

16. Finished pipes must be accepted technical control supplier company. The supplier must ensure that all manufactured pipes comply with the requirements of this standard.

III. TEST METHODS

17. (Cancelled - "Informative Index of Standards" No. 2 1978).

18. Each batch pipe must be inspected and measured. The batch must consist of pipes of the same size in diameter and wall thickness, made of steel of the same grade and type of heat treatment. The number of pipes in a batch should not exceed 500 pieces. for pipes with a diameter of up to 30 mm and 300 pcs. for pipes with a diameter over 30 mm.

19. Inspection of pipes should be carried out without the use of magnifying devices. The depth of defects must be checked in one or more places by filing or another method.

25. The distribution test is carried out according to GOST 8694-75 in a cold state.

26. The boarding test is carried out in accordance with GOST 8693-80.

27. The bend test is carried out according to GOST 3728-78 in a cold state.

28. The grain size is determined by the base metal of the pipes according to GOST 5639-65.

29. Testing for intergranular corrosion is carried out in accordance with GOST 6032-75 using the AM or D method or both methods simultaneously. The test method is specified in the order.

Notes:

1. Using method D, pipes made of steel grades OOX18NYUT are tested; 08Х18Н10Т and 08XI8H12T.

2. If the order requires testing pipes for intergranular corrosion, but does not specify a method, the pipes must be tested using the AM method

30. Hydraulic testing of pipes is carried out in accordance with GOST 3845-75 with exposure to pressure for at least 10 s.

Each pipe must be subjected to a hydraulic test.

31. If the test results are unsatisfactory for at least one of the indicators, it is re-tested on a double number of samples taken from the same batch of pipes.

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INTERSTATE STANDARD

ELECTRIC WELDED PIPES FROM
CORROSION-RESISTANT STEEL

Specifications

IPC PUBLISHING HOUSE OF STANDARDS

Moscow

INTERSTATE STANDARD

By Decree of the USSR State Committee on Standards dated October 20, 1981 No. 4629, the implementation date was set as 01/01/83

The validity period was lifted according to the protocol of the Interstate Council for Standardization, Metrology and Certification (IUS 2-93)

This standard applies to electric-welded pipes made of corrosion-resistant (stainless) steels intended for the manufacture of pipelines and various structures.

(Changed edition, Amendment No. 2).

1. ASSORTMENT

1.1. The dimensions of the pipes must correspond to those indicated in the table. 1.

Table 1

Notes:

1. Pipe sizes taken in brackets are not recommended when designing new facilities.

2. Theoretical mass of 1 m of pipes ( T), kg, calculated by the formula

Where D n - nominal outer diameter of the pipe, mm;

s n - nominal pipe wall thickness, mm;

γ - metal density, g/cm 3, depending on the steel grade:

08Х18Н10Т, 10Х18Н10Т, 12Х18Н10Т, 03Х18Н10Т, 08Х18Н10 - 7.9;

08Х21Н6М2Т - 7.85;

10Х17Н13М2Т, 10Х17Н13М3Т, 03Х17Н13М2Т, 03Х17Н14М3 - 8.0;

06ХН28МДТ - 7.95;

04X17T, 08X18T1 - 7.72.

3. Pipes from steel grades 08Х18Т1 and 04Х17Т are manufactured with a wall thickness of up to 2.0 mm.

4. By agreement between the manufacturer and the consumer, pipes can be manufactured: of intermediate sizes with tolerances for the diameter and wall thickness of adjacent large sizes; from corrosion-resistant steels of the best grades; with mixed or one-sided tolerance on the outer diameter. The size of the offset or one-sided tolerance field should not exceed the sum of two-sided deviations.

(Changed edition, Amendment No. 2).

1.2. According to the length of the pipe, the following should be made:

measured length - from 5 to 9 m;

measured length with the remainder - no more than 10% (by weight) of pipes of unmeasured length;

multiple measured length - up to 9 mm with an allowance for each cut of 5 mm (unless another allowance is specified in the order), which is included in each multiple length;

multiple lengths with a remainder of no more than 10% (by weight) of pipes of unmeasured length;

unmeasured length - from 1.5 to 9 m.

1.3. Maximum deviations along the length of pipes of measured and multiple lengths should not exceed +15 mm.

1.2, 1.3 (Changed edition, Amendment No. 1).

1.4. The maximum deviations for the outer diameter and wall thickness are indicated in table. 2.

table 2

At the request of the consumer, pipes with dimensions of 38´1.5 and 43´1.5 mm are manufactured with maximum deviations in outer diameter mm.

1.4(Changed edition, Amendment No. 1, 2).

1.5. Ovality and variation in wall thickness of pipes should not take the pipe dimensions beyond the maximum deviations in diameter and wall thickness, respectively.

1.6. The tolerance for straightness of pipes should not exceed 1.5 mm per 1 m of length.

Examples of symbols

Pipe, outer diameter 25 mm and wall thickness 2 mm, of unmeasured length, made of steel grade 08Х18Н10Т:

Pipe 25 ´2 - 08Х18Н10Т GOST 11068-81

The same, with a length multiple of 2000 mm:

Pipe 25 ´2´2000 kr - 08Х18Н10Т GOST 11068-81

The same, measured length 6000 mm:

Pipe 25 ´2´6000 - 08Х18Н10Т GOST 11068-81

The same, with increased manufacturing precision:

Pipe 25P´2П´6000 - 08Х18Н10Т GOST 11068-81

For heat-treated pipes, the letter T is placed after the word pipe.

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner, from steel grades 10Х18Н10Т and 04Х17Т with the chemical composition specified in table. 3, and steel grades 08Х18Н10Т, 08Х18Т1, 08Х18H10, 12Х18Н10Т, 10Х17Н13М2Т, 10Х17Н13М3Т, 08Х22Н6Т, 08Х21Н6М2Т, 06ХН28МДТ, 08Х17Н13М2Т, 03Х 17N14M3, 03Х18Н10Т with chemical composition in accordance with GOST 5632-72.

Table 3

2.2 Pipes made from steel grades 08Х18Н10Т, 08Х18Т1, 10Х18Н10Т, 12Х18Н10Т, 04Х17Т are produced by heat-treated mechanical properties, indicated in table. 4. The mechanical properties of pipes made of steel 08Х18Т1 and 04Х17Т for wall thicknesses of more than 1.5 mm are established by agreement of the parties.

Table 4

2.1, 2.2 (Changed edition, Amendment No. 2).

2.2.1. Pipes from other grades of steel specified in clause 2.1 are manufactured heat-treated, and at the request of the consumer, without heat treatment; in this case, the mechanical properties are established by agreement between the manufacturer and the consumer.

The number of pipes in a batch should be no more than:

500 pcs. - with a diameter of up to 30 mm;

300 pcs. - with a diameter over 30 mm.

3.2. The chemical composition of steel is taken according to the document on the quality of the original coiled steel. If there is a disagreement in the assessment of the chemical composition, one pipe from the batch is selected for testing.

3.3. Each batch of pipes is subjected to checking the surface quality and dimensions, as well as testing the pipes with hydraulic pressure or non-destructive methods.

At the request of the consumer, when monitoring the welded seam of pipes using non-destructive methods, an additional hydraulic pressure test is carried out on 10 to 100% of the pipes in the batch.

3.4. To check the height of the internal flash, 2% of the pipes from the batch are selected.

3.5. For tensile testing, intergranular corrosion, expansion, beading, bending, and flattening, two pipes from the batch are selected. To determine the grain size, one tube from the batch is selected.

The determination of the yield strength of the metal is carried out at the request of the consumer.

3.6. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double number of pipes selected from the same batch.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. One sample is cut from each selected pipe for each type of test.

4.2. Chemical analysis is carried out according to GOST 12344-88, GOST 12346-78, GOST 12347-77, GOST 12348-78, or, or with a micrometer according to GOST 6507-90;

deviation from straightness - with a straight edge in accordance with GOST 8026-92 and a feeler gauge in accordance with the regulatory document;

wall thickness, thickness difference and internal burr height - with a micrometer according to GOST 6507-90 or a wall gauge according to GOST 11358-89. The height of the internal flash is measured at a distance of up to 25 mm from the ends of the pipes, and the outer diameter is measured at least 15 mm from the ends of the pipes.

It is allowed to control the length, outer diameter and wall thickness of pipes by automatic means according to regulatory documentation. In case of disagreement in the assessment of measurement results, control is carried out using the measuring instruments given above.

On a short longitudinal sample (in the form of a strip with a seam or a piece of pipe). The test speed up to the yield point should be no more than 10 mm/min, beyond the yield point - no more than 40 mm/min.

4.13. Non-destructive quality control of the weld is carried out according to regulatory documentation.

4.14. The right angle for cutting pipe ends is not controlled and is determined by the design of the pipe cutting equipment.

(Introduced additionally, Amendment No. 1).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage - in accordance with GOST 10692-80.

(Changed edition, Amendment No. 1).

5.2 (Deleted, Amendment No. 2).

Change No. 2 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 10 of 03.10.96)

STATE STANDARD OF THE USSR UNION

By Decree of the USSR State Committee on Standards of October 20, 1981 No. 4629, the introduction date was set

01.01.83

The validity period was lifted according to the protocol of the Interstate Council for Standardization, Metrology and Certification (IUS 2-93)

This standard applies to electric-welded pipes made of corrosion-resistant (stainless) steels intended for the manufacture of pipelines and various structures.

1. ASSORTMENT

1.1. The dimensions of the pipes must correspond to those indicated in the table. .

Table 1

(Changed edition, Amendment No. 2).

At the request of the consumer, pipes of size 38´ 1.5 and 43 ´ 1.5 mm are manufactured with maximum deviations in outer diameter mm.

1.1 - 1.4.

1.5. Ovality and variation in wall thickness of pipes should not take the pipe dimensions beyond the maximum deviations in diameter and wall thickness, respectively.

1.6. The tolerance for straightness of pipes should not exceed 1.5 mm per 1 m of length.

Examples of symbols

Pipe, outer diameter 25 mm and wall thickness 2 mm, of unmeasured length, made of steel grade 08Х18Н10Т:

Pipe 25 ´ 2 - 08Х18Н10Т GOST 11068-81

The same, with a length multiple of 2000 mm:

Pipe 25 ´ 2 ´ 2000 kr - 08Х18Н10Т GOST 11068-81

The same, measured length 6000 mm:

Pipe 25 ´ 2 ´ 6000 - 08Х18Н10Т GOST 11068-81

The same, with increased manufacturing precision:

Pipe 25P ´ 2P´ 6000 - 08Х18Н10Т GOST 11068-81

For heat-treated pipes, the letter T is placed after the word pipe.

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner, from steel grades 10Х18Н10Т and 04Х17Т with the chemical composition specified in table. , and steel grades 08Х18Н10Т, 08Х18Т1, 08 X 18H 10, 12Х18Н10Т, 10Х17Н13М2Т, 10Х17Н13М3Т, 08Х22Н6Т, 08Х21Н6М2Т, 06ХН28МДТ, 08Х17Н13М2Т, 03Х17Н14М3, 03Х18Н10Т with chemical composition according to GOST 5632-72.

Table 3

2.2 Pipes made from steel grades 08Х18Н10Т, 08Х18Т1, 10Х18Н10Т, 12Х18Н10Т, 04Х17Т are manufactured by heat treatment with mechanical properties specified in table. 226 (23)

2.1, 2.2 (New edition, Amendment No. 2).

2.2.2. By agreement with the consumer, pipes can be subjected to cold and warm deformation in the mill line.

(Introduced additionally, Amendment No. 2).

2.3. Lack of penetration, pores, cracks, films, flaws, scale, and traces of over-etching are not allowed on the surface of the pipes.

Scratches, traces of straightening, scratches, traces of cleaning defects are allowed, if the thickness of the pipe wall does not exceed the maximum deviations, as well as tarnished colors formed as a result of heat treatment or welding.

By agreement with the consumer, it is possible to supply pipes made of steels 08Х18Т1 and 04Х17Т with an oxide film on the surface formed as a result of heat treatment.

Pipes can be produced with a polished outer surface. Roughness is established by agreement with the consumer.

On the outer surface of the pipes in places where they come into contact with the gasket, unetched areas are allowed due to the etching technology.

(New edition, Amendment No. 2).

2.4. The height of the internal flashing should not exceed:

0.7 mm - for general purpose pipes;

0.1 mm - for pipes used for the production of tubular heating elements.

At the request of the consumer pipes general purpose with a nominal internal diameter of over 20 mm, they are manufactured with a burr height of no more than 0.3 mm. The transition from the burr to the pipe walls should be smooth.

2.5. The ends of the pipes must be cut at right angles and cleared of burrs. Formation of a chamfer is allowed when removing burrs. At the request of the consumer, it is allowed to manufacture pipes with deburring and internal chamfering from one end, provided that the stripped ends are oriented in one direction.

At the customer's request, pipes are manufactured cut in line.

(New edition, Amendment No. 2).

2.6. For chemical engineering, the chemical industry, and at the request of the consumer for other industries, heat-treated pipes of their steel grades 08Х18Н10Т, 10Х18Н10Т, 10Х17Н13М2Т, 10Х17Н13М3Т, 08Х22Н6Т, 08Х21Н6М2Т, 06ХН28МДТ must withstand the intercrystal test Stallite corrosion.

2.7. Pipes made of steel grades 08Х18Н10Т, 10Х18Н10Т must withstand the flattening test up to a distance ( N) between flattening planes in millimeters, calculated by the formula

Where S n - nominal pipe wall thickness, mm;

D n - nominal outer diameter of the pipe, mm.

At customer's request for pipes with ratioS n/ D n , equal to 0.04 or more, distance N should not be more than 1/3D n.

Heat-treated pipes made of other steel grades must withstand the flattening test to a distance N, equal to 1/2 of the outer diameter.

Pipes without heat treatment must withstand the flattening test to a distance N, equal to 2/3 of the outer diameter.

(New edition, Amendment No. 2).

2.8. At the request of the consumer, heat-treated pipes must withstand the following tests:

expansion tests before increasing the outer diameter:

by 12% - for pipes of steel grades 08Х18Н10Т, 08Х18Т1, 08Х18Н10, 12Х18Н10Т, 10Х18Н10Т, 04Х17Т, 03Х18Н10Т, 08Х17Н13М2Т, 03Х17Н14М3;

by 6% - for pipes made of other steel grades.

By agreement of the parties, pipes made of steel grades 08Х18Т1, 10Х18Н10Т, 12Х18Н10Т must withstand the expansion test by 15%;

bead test until the width of the bent bead, measured from the inner surface of the pipe, is equal to 1.5 times the wall thickness (bead test is carried out on pipes with a diameter of at least 25 mm; bead angle 90° );

bend test (the bend radius is established by agreement between the manufacturer and the consumer).

(New edition, Amendment No. 2).

2.9. At the consumer's request, the metal grain size of finished pipes made of steel grades 10Х18Н10Т and 12Х18Н10Т should be 3 - 7 points.

2.10. Pipes must withstand a test hydraulic pressure of 6 MPa (60 kgf/cm2) or control of the continuity of the weld using non-destructive methods.

At the request of the consumer, pipes must withstand hydraulic pressure ( R 1) in accordance with the requirements of GOST 3845-75, but not more than 20 MPa (200 kgf/cm2). In this case, the permissible stress in the pipe wall is taken equal to 40% of the temporary tensile strength.

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size in diameter and wall thickness, the same grade of steel, the same type of heat treatment and be accompanied by one quality document in accordance with GOST 10692-80.

The number of pipes in a batch should be no more than:

500 pcs. - with a diameter of up to 30 mm;

300 pcs. - with a diameter over 30 mm.

3.2. The chemical composition of steel is taken according to the document on the quality of the original coiled steel. If there is a disagreement in the assessment of the chemical composition, one pipe from the batch is selected for testing.

3.3. Each batch of pipes is subjected to checking the surface quality and dimensions, as well as testing the pipes with hydraulic pressure or non-destructive methods.

At the request of the consumer, when monitoring the welded seam of pipes using non-destructive methods, an additional hydraulic pressure test is carried out on 10 to 100% of the pipes in the batch.

(Changed edition, Amendment No. 1).

3.4. To check the height of the internal flash, 2% of the pipes from the batch are selected.

3.5. For tensile testing, intergranular corrosion, expansion, beading, bending, and flattening, two pipes from the batch are selected. To determine the grain size, one tube from the batch is selected.

The determination of the yield strength of the metal is carried out at the request of the consumer.

3.6. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double number of pipes selected from the same batch.

The results of repeated tests apply to the entire batch.

4. TEST METHODS

4.1. One sample is cut from each selected pipe for each type of test.

4.2. Chemical analysis is carried out according to GOST 12344-88, GOST 12346-78, GOST 12347-77, GOST 12348-78, GOST 12349-83, GOST 12350-78, GOST 12351-81, GOST 12352-81, GOST 12353-78, GOST 12354-81, GOST 12355-78, GOST 12356-81, GOST 12365-84 or GOST 28473-90,

wall thickness, thickness difference and internal burr height - with a micrometer according to GOST 6507-90 or a wall gauge according to GOST 11358-89. The height of the internal flash is measured at a distance of up to 25 mm from the ends of the pipes, and the outer diameter is measured at least 15 mm from the ends of the pipes.

It is allowed to control the length, outer diameter and wall thickness of pipes by automatic means according to regulatory documentation. In case of disagreement in the assessment of measurement results, control is carried out using the measuring instruments given above.

(Changed edition, Amendment No. 1, 2).

4.5. The grain size is determined by the base metal according to GOST 5639-82. In this case, the pipes are not tested for intergranular corrosion.

4.6. Sampling and testing for intergranular corrosion are carried out in accordance with GOST 6032-89. In case of disagreement in assessing the results, tests are carried out according to the method A.M. GOST 6032-89, except for pipes made of steel grade 06ХН28МДТ.

(Changed edition, Amendment No. 1).

4.7. The tensile test is carried out according to GOST 10006-80 on a short longitudinal sample (in the form of a strip with a seam or a piece of pipe). The test speed up to the yield point should be no more than 10 mm/min, beyond the yield point - no more than 40 mm/min.

4.8. Hydraulic testing is carried out in accordance with GOST 3845-75 with holding pressure for at least 5 s.

4.9. The expansion test is carried out according to GOST 8694-75 on a mandrel with a taper of 30°.

4.10. The boarding test is carried out according to GOST 8693-80.

4.11. The flattening test is carried out according to GOST 8695-75 with the weld positioned horizontally. At the request of the consumer, the test should be carried out in two positions of the weld seam: horizontally and vertically.

(Changed edition, Amendment No. 2).

4.12. The bending test is carried out according to GOST 3728-78.

4.13. Non-destructive quality control of the weld is carried out according to regulatory documentation.

4.14. The right angle for cutting pipe ends is not controlled and is determined by the design of the pipe cutting equipment.

(Introduced additionally, Amendment No. 1).

5. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Labeling, packaging, transportation and storage - in accordance with GOST 10692-80.

(Changed edition, Amendment No. 1).

5.2. (Deleted, Amendment No. 2).

* increased accuracy

According to the length of the pipe we supply:

• unmeasured length from 1.5 to 9 m;
• measured from 5 to 9 m;
• a multiple of the measured one within the unmeasured limit, with an allowance for each cut of 5 mm (unless otherwise specified).

In a batch of pipes of unmeasured length, 5% of pipes not shorter than 0.5 m are allowed.

Permissible deviations for the total length are +15mm.

Ovality and thickness variations should not take the size of the pipes beyond their maximum deviations.

The curvature of any section of the pipe per 1 m should not exceed 1.5 mm.

Technical requirements

Pipes are supplied in a heat-treated state.

Upon customer's request, without heat treatment.

Pipes are made from corrosion-resistant steels, chemical composition which must comply with GOST 563272.

Steel grades 10Х17Н13М2Т, 10H17№13М3Т, 08H22№6Т, 12H21№5Т, 10Х17Н13М3Т, 08Х22Н6Т, 12Х21Н5Т, 06ХН28МТ, 06ХН28МДТ are used by agreement between the manufacturer and the consumer.

The ends of the pipes must be cut at right angles and cleared of burrs.

The height of the internal burr should not exceed 0.7 mm. At the customer's request, pipes DN20 mm are supplied with an internal flash no more than 0.3 mm high.

At the customer's request, pipes must be subjected to one or two types of tests listed below:

• flattening by the amount H=1/2 Dn for heat-treated pipes and H=2/3 Dn for pipes without heat treatment;
• expansion on a mandrel with a taper of 1:10 for heat-treated pipes until the outer diameter increases by 10% -12%;
• beading at an angle of 90° for heat-treated pipes DнЄ25 mm. The width of the bead from the inner surface of the pipe must be at least 1.5 S;
• bend bend radius is taken in accordance with GOST 984261 by agreement of the parties.

Pipes tested for beading are not subject to expansion testing.

Pipes must withstand a hydraulic pressure test of 6 MPa.

At the customer's request, the pressure can be increased, but should not exceed the value determined by the formula GOST 384572 (but not more than 20 MPa).

With 100% control of the weld using non-destructive physical methods, hydrotesting is carried out selectively.

At the customer's request, heat-treated pipes must withstand the intergranular corrosion test.

Pipes made from steel 10Х18Н10Т are supplied with a guaranteed grain size within 37 points. In this case, control is not carried out at the ICC.

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