STATE STANDARD OF THE USSR UNION

STEEL PIPES
ELECTRIC WELDED STRAIGHT SEWING

TECHNICAL REQUIREMENTS

1.2. Depending on the quality indicators, pipes are manufactured into the following groups:

A - according to mechanical properties from carbon steel grades St2, St3 (all degrees of deoxidation) according to GOST 380-94, category 1 according to GOST 14637-89;

B - according to the chemical composition of carbon steel grades St2, St3 (all degrees of deoxidation) with a chemical composition in accordance with GOST 380-94 and GOST 14637-89;

B - by chemical composition and mechanical properties made of carbon steel grades St2 (all degrees of deoxidation) according to GOST 380-94, category 2 according to GOST 14637-89, St3kp according to GOST 380-94, categories 2 and 3 according to GOST 14637-89, St3ps, St3sp according to GOST 380-94, categories 2, 3, 4 and 5 according to GOST 14637-89, as well as from low-alloy steel, the carbon equivalent of which does not exceed 0.48%;

D - without standardization of mechanical properties and chemical composition, but with normalization of hydraulic test pressure.

(New edition, Amendment No. 4).

1.3. (Deleted, Amendment No. 3).

1.4. The mechanical properties of the base metal of the pipes must comply with the standards specified in table. 2.

Table 2

(New edition, Amendment No. 4).

1.5. Pipes of groups A and B must withstand mechanical tests welded joint tensile strength according to GOST 6996-66. The tensile strength of the welded joint must not be lower than the tensile strength of the base metal established for pipes made of a given steel grade.

1.6. At the request of the consumer, group B pipes must withstand the impact strength test of the base metal. The impact strength standards of the base metal must correspond to those indicated in the table. 3.

Table3

(New edition, Amendment No. 4).

For main heating networks, pipes are made heat-treated from steel grade St3sp 4, 5 with mechanical properties specified in table. 3a.

Table 3a

The standards for impact strength of a welded joint of pipes for heating networks at a temperature of minus 20°C must not be lower than the standards for the base metal given in Table. 3a.

The standards for impact strength after mechanical aging for the base metal of pipes and at minus 20°C for a welded joint are optional until July 1, 1988.

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

1.7. Pipes with a diameter of up to 820 mm must have no more than one longitudinal and one transverse seam. Pipes with a diameter of 820 mm or more can have two longitudinal and one transverse seam. At the request of the consumer, an increase in the number of transverse seams is allowed.

If there is a transverse seam, the longitudinal seams must be offset from one another by a distance of at least 100 mm. At the request of the consumer, an upper limit for the displacement of longitudinal seams relative to each other is established.

1.8. The height of the reinforcement bead for external longitudinal and transverse seams must comply with the standards specified in table. 4.

Table 4

In places where seams and tacks are repaired, it is allowed to increase the height of the reinforcement roller by 1 mm above the norms specified in the table. 4.

Height of the reinforcement roller at the center inseam must be at least 0.5 mm. It is allowed at the ends of pipes with a length of at least 150 mm to remove the reinforcement of the internal seam to a height of 0 - 0.5 mm.

(New edition, Amendment No. 4).

1.9. The ends of the pipes must be cut at right angles. The deviation from the right angle (cut bevel) should not exceed that indicated in the table. 5.

Table 5

(Changed edition, Amendment No. 4).

1.10. The ends of the pipes must be chamfered at an angle of 25 - 30° to the end of the pipe. In this case, an end ring (blunt) with a width of 1.0 - 3.0 mm should be left - for pipes with a diameter of up to 1020 mm inclusive, and a width of 1.0 - 5.0 mm - for pipes with a diameter of more than 1020 mm.

At the consumer's request, the bevel angle should be 30 - 35°, and for pipes with a wall thickness of 17 mm or more, the edges should be cut in accordance with the drawing. 1.

It is allowed to cut edges in accordance with the drawing. 1 is carried out on pipes with a wall thickness of 15 mm.

(Changed edition, Amendment No. 4).

1.11. Cracks, stains, shells, delaminations and sunsets on the surface of pipes are not allowed.

Minor nicks, ripples, dents, small scratches, a thin layer of scale, traces of stripping and welding of defects are allowed if they do not take the wall thickness beyond the maximum deviations. In addition, a longitudinal mark with a depth of no more than 0.2 mm is allowed, applied during automatic welding to guide the seam.

It is allowed to weld pipe defects with subsequent cleaning of the welding site and re-testing with hydraulic pressure.

1.12. Surface defects of the weld metal in the form of pores, cavities, cracks, fistulas and other defects that reduce the density and strength of the weld metal below the level of the base metal are not allowed.

Traces of metal shrinkage along the longitudinal axis of the seam (sink) are allowed. In this case, the amount of shrinkage should not bring the reinforcement height beyond the permissible minimum seam height.

The transition from the weld reinforcement to the base metal should be smooth (without undercuts).

Undercuts up to 0.5 mm deep are allowed without repair. If the undercuts on the outer and inner seams coincide, one of them must be repaired.

Allowed to make repairs welded pipes followed by testing them with hydraulic pressure or monitoring the repair site using physical methods.

1.13. Each pipe must withstand the hydraulic pressure test.

Pipes of group A are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 ( R 1), while the permissible stress is taken equal to 0.5 of the minimum tensile strength value established for a given steel grade.

According to the customer's order, the permissible stress should be equal to 0.85 of the minimum value of the yield strength.

Pipes of group B are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 (R 1), with a permissible stress equal to 0.9 of the minimum value of the yield strength established for a given steel grade.

Pipes of groups D and B must withstand a hydraulic pressure test of at least 25 kgf/cm2 (2.5 MPa). Pipes with dimensions 920´7, 1020´8, 1120´8, 1120´9, 1220´9, 1220´10, 1320´9, 1320´10, 1320´11, 1420´10 and 1420´11 mm are subjected to a floor pressure of 20 kgf/cm 2 (2.0 MPa).

When testing on presses of various designs with axial support, the value of hydraulic pressure is determined in accordance with the requirements of GOST 3845-75.

Pipes longer than 10 m, obtained by joining, or more than two pipes that have passed hydrotests are not subject to hydrotesting. At the request of the consumer, the transverse weld must be controlled by non-destructive physical methods.

(Changed edition, Amendment No. 2, 4).

1.14. Welded seams of pipes for heating networks must be inspected using non-destructive methods along their entire length.

At the request of the consumer, welded joints of group B pipes must be controlled by non-destructive methods.

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

1.15. Welded joints of pipes for main heating networks must be subjected to static bending tests.

The minimum permissible bend angle for a welded joint of carbon steel pipes is at least 100°.

(Introduced additionally, Amendment No. 2).

2. ACCEPTANCE RULES

2.1. Pipes are presented for acceptance in batches. The batch must consist of pipes of the same size, the same steel grade and the same manufacturing group and be accompanied by one quality document in accordance with GOST 10692-80.

The number of pipes in a batch should not exceed 100 pieces.

2.2. Each pipe is inspected and measured.

2.3. Each pipe is subjected to hydraulic pressure testing.

2.4. To control the mechanical properties and impact strength, the following are selected from the batch:

for single-seam pipes - two pipes;

for double-seam pipes - one pipe.

(Changed edition, Amendment No. 4).

2.5. The chemical composition of steel is accepted according to the document on the quality of the workpiece manufacturer. If necessary, the chemical composition of finished pipes is checked on one pipe from the batch.

2.6. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double sample taken from the same batch or heat.

The results of repeated tests apply to the entire batch.

(Changed edition, Amendment No. 2).

3. TEST METHODS

3.1. The chemical composition of steel is checked, if necessary, according to GOST 22536.0-87, GOST 22536.1-88, GOST 22536.2-87, GOST 22536.3-88, GOST 22536.4-88, GOST 22536.5-87, GOST 22536.6-88. Samples to determine the chemical composition of steel are taken according to GOST 7565-81.

(Changed edition, Amendment No. 4).

3.2. Outside diameter pipes ( D m) in millimeters is checked by measuring the perimeter and calculated using the formula

Where R - pipe cross-sectional perimeter, mm;

D R- thickness of the tape measure, mm;

0.2 - error when measuring the perimeter due to the skew of the tape measure when the divisions are aligned.

(Changed edition, Amendment No. 1).

3.3. Hydraulic testing of pipes must be carried out in accordance with GOST 3845-75 with exposure under pressure for at least 10 s.

3.4. To conduct a tensile test of the base metal and welded joint, one image is cut out from each selected pipe. Samples are taken in accordance with GOST 7564-73.

Tensile testing of the base metal is carried out on five-fold transverse samples in accordance with GOST 10006-80.

Instead of tensile testing, it is allowed to inspect pipes using non-destructive methods that ensure compliance of mechanical properties with the standards specified in this standard.

In case of disagreement in assessing the level of mechanical properties, tests are carried out according to GOST 10006-80.

It is allowed to test the tensile strength of the base metal of pipes made of low-alloy steels in accordance with regulatory documentation approved in the prescribed manner.

(Changed edition, Amendment No. 4).

3.5. The tensile test of the welded joint must be carried out in accordance with GOST 6996-66 on type XII samples with the reinforcement removed. Samples for tensile testing of a welded joint are taken perpendicular to the seam.

3.6. To carry out the impact bending test, three samples of the base metal and three samples of the welded joint are cut from each selected pipe. To test the base metal for impact bending after mechanical aging, three additional samples are selected in accordance with GOST 9454-78.

Inspection of the base metal of pipes for impact bending is carried out on samples cut perpendicular to the pipe axis. Tests are carried out in accordance with GOST 9454-78 on samples of type I with a wall thickness of more than 10 mm and type 3 with a thickness of 10 mm or less.

Inspection of a welded joint for impact bending is carried out on samples of type VII with a wall thickness of 10 mm or less and type VI with a wall thickness of 11 mm or more in accordance with GOST 6996-66. The notch on impact samples is made along the fusion line of the last welded seam, perpendicular to the rolling surface of the metal.

The impact strength of the base metal and welded joint is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, it is allowed to reduce the impact strength by 4.9 J/cm 2 (0.5 kgf m/cm 2), except for pipes intended for heating networks.

(Changed edition, Amendment No. 2).

3.7. When making samples for mechanical testing, it is allowed to straighten samples using a static load.

3.8. Method and technique of quality control weld are established by physical methods by the manufacturer.

The standards for permissible defects determined by non-destructive testing methods are established by normative and technical documentation approved in the prescribed manner.

3.9. Carbon equivalent for a single heat of low alloy steel ( E) as a percentage is calculated using the formula

Where WITH, Mn, V- mass fraction of carbon, manganese and vanadium, %.

(Introduced additionally, Amendment No. 1).

3.10. The test for susceptibility to mechanical aging must be carried out according to GOST 7268-82 without preliminary 10% deformation.

3.11. Measure on the pipe:

Curvature - using a straight edge and a feeler gauge according to TU 2-034-225-87;

cutting bevel - this parameter is ensured by the design of equipment for processing pipe ends;

the depth of the defect at the cleaning site - a depth gauge in accordance with GOST 162-90;

the end ring at the ends of the pipes (blunting) - with a ruler according to GOST 427-75;

chamfer bevel angle - goniometer according to GOST 5378-88.

(Changed edition, Amendment No. 4).

3.12. Static bending testing of pipes is carried out according to regulatory and technical documentation.

3.10 - 3.12.(Introduced additionally, Amendment No. 2).

4. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

4.1. Labeling, packaging, transportation and storage of pipes - according to

STATE STANDARD OF THE USSR UNION

STEEL PIPES
ELECTRIC WELDED STRAIGHT SEWING

TECHNICAL REQUIREMENTS

GOST 10706-76
(ST SEV 489-77)

PUBLISHING HOUSE OF STANDARDS

Moscow

STATE STANDARD OF THE USSR UNION

Validity __ from 01/01/78

_until 01/01/96

This standard applies to straight-seam electric welded pipes general purpose diameter 478 - 1420 mm.

(New edition, Amendment No. 4).

1. TECHNICAL REQUIREMENTS

A - according to mechanical properties of carbon steel grades St2, St3 (all degrees of deoxidation) according to GOST 380-94, category 1 according to GOST 14637-89;

B - according to the chemical composition of carbon steel grades St2, St3 (all degrees of deoxidation) with a chemical composition in accordance with GOST 380-94 and GOST 14637-89;

B - according to the chemical composition and mechanical properties of carbon steel grades St2 (all degrees of deoxidation) according to GOST 380-94, category 2 according to GOST 14637-89, St3kp according to GOST 380-94, categories 2 and 3 according to GOST 14637-89, St3ps , St3sp according to GOST 380-94, categories 2, 3, 4 and 5 according to GOST 14637-89, as well as from low-alloy steel, the carbon equivalent of which does not exceed 0.48%;

D - without standardization of mechanical properties and chemical composition, but with standardization of hydraulic test pressure.

(New edition, Amendment No. 4).

1.3. (Deleted, Amendment No. 3).

1.4. The mechanical properties of the base metal of the pipes must comply with the standards specified in table. .

table 2

(New edition, Amendment No. 4).

Pipe wall thickness, mm

Impact strength KCU, kgf × m/cm 2 (MJ/m 2), at test temperature, ° WITH

St3ps3, St3sp3

From 5 to 9 inclusive.

St. 9 "25"

5,0 (0,49)

St3ps4, St3sp4

From 5 to 9 inclusive.

St. 9 "25"

Low alloy steel

All walls

Note: By agreement between the manufacturer and the consumer, the impact strength of the base metal of low-alloy steel pipes at minus 60 ° C must be at least 2.5 kgf × m/cm2 (0.24 MJ/m2).

(New edition, Amendment No. 4).

For main heating networks, pipes are made heat-treated from steel grade St3sp 4, 5 with mechanical properties specified in table. .

Table 3a

Norms of impact strength of welded pipe joints for heating networks at a temperature of minus 20° C must not be lower than the base metal standards given in table. .

Norms of impact strength after mechanical aging for the base metal of pipes and at minus 20° C for welded joints are optional until July 1, 1988.

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

1.7. Pipes with a diameter of up to 820 mm must have no more than one longitudinal and one transverse seam. Pipes with a diameter of 820 mm or more can have two longitudinal and one transverse seam. At the request of the consumer, an increase in the number of transverse seams is allowed.

If there is a transverse seam, the longitudinal seams must be offset from one another by a distance of at least 100 mm. At the request of the consumer, an upper limit for the displacement of longitudinal seams relative to each other is established.

(Changed edition, Amendment No. 1).

1.8. The height of the reinforcement bead for external longitudinal and transverse seams must comply with the standards specified in table. .

Table 4

mm

In places where seams and tacks are repaired, it is allowed to increase the height of the reinforcement roller by 1 mm above the norms specified in the table. .

The height of the reinforcement bead in the center of the internal seam must be at least 0.5 mm. It is allowed at the ends of pipes with a length of at least 150 mm to remove the reinforcement of the internal seam to a height of 0 - 0.5 mm.

(New edition, Amendment No. 4).

1.9. The ends of the pipes must be cut at right angles. The deviation from the right angle (cut bevel) should not exceed that indicated in the table. .

Table 5

mm

1.10. The ends of the pipes must be chamfered at an angle of 25 - 30° to the end of the pipe. In this case, an end ring (blunt) with a width of 1.0 - 3.0 mm should be left - for pipes with a diameter of up to 1020 mm inclusive, and a width of 1.0 - 5.0 mm - for pipes with a diameter of more than 1020 mm.

At the consumer's request, the bevel angle should be 30 - 35° , and for pipes with a wall thickness of 17 mm or more, the cutting of the edges must be done in accordance with the drawing. .

It is allowed to cut edges in accordance with the drawing. carry out on pipes with a wall thickness of 15 mm.

Crap. 1

(Changed edition, Amendment No. 4).

1.11. Cracks, stains, shells, delaminations and sunsets on the surface of pipes are not allowed.

Minor nicks, ripples, dents, small scratches, a thin layer of scale, traces of stripping and welding of defects are allowed if they do not take the wall thickness beyond the maximum deviations. In addition, a longitudinal mark with a depth of no more than 0.2 mm is allowed, applied during automatic welding to guide the seam.

It is allowed to weld pipe defects with subsequent cleaning of the welding site and re-testing with hydraulic pressure.

1.12. Surface defects of the weld metal in the form of pores, cavities, cracks, fistulas and other defects that reduce the density and strength of the weld metal below the level of the base metal are not allowed.

Traces of metal shrinkage along the longitudinal axis of the seam (sink) are allowed. In this case, the amount of shrinkage should not bring the reinforcement height beyond the permissible minimum seam height.

The transition from the weld reinforcement to the base metal should be smooth (without undercuts).

Undercuts up to 0.5 mm deep are allowed without repair. If the undercuts on the outer and inner seams coincide, one of them must be repaired.

It is allowed to repair welded pipes followed by testing them with hydraulic pressure or monitoring the repair site using physical methods.

Pipes of group A are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 ( R 1), while the permissible stress is taken equal to 0.5 of the minimum tensile strength value established for a given steel grade.

According to the customer's order, the permissible stress should be equal to 0.85 of the minimum value of the yield strength.

Pipes of group B are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 (R 1), with a permissible stress equal to 0.9 of the minimum value of the yield strength established for a given steel grade.

Pipes of groups D and B must withstand a hydraulic pressure test of at least 25 kgf/cm2 (2.5 MPa). Pipes size 920´ 7, 1020 ´ 8, 1120 ´ 8, 1120 ´ 9, 1220 ´ 9, 1220 ´ 10, 1320 ´ 9, 1320 ´ 10, 1320 ´ 11, 1420 ´ 10 and 1420 ´ 11 mm test the floor with a pressure of 20 kgf/cm 2 (2.0 MPa).

When testing on presses of various designs with axial support, the value of hydraulic pressure is determined in accordance with the requirements of GOST 3845-75.

Pipes longer than 10 m, obtained by joining, or more than two pipes that have passed hydrotests are not subject to hydrotesting. At the request of the consumer, the transverse weld must be controlled by non-destructive physical methods.

(Changed edition, Amendment No. 2, 4).

1.14. Welded seams of pipes for heating networks must be inspected using non-destructive methods along their entire length.

At the request of the consumer, welded joints of group B pipes must be controlled by non-destructive methods.

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

1.15. Welded joints of pipes for main heating networks must be subjected to static bending tests.

The minimum permissible bend angle for a welded joint of pipes made of carbon steel is not less than 100° .

The standard for testing welded joints for static bending is optional until July 1, 1988.

(Introduced additionally, Amendment No. 2).

2. ACCEPTANCE RULES

Instead of tensile testing, it is allowed to inspect pipes using non-destructive methods that ensure compliance of mechanical properties with the standards specified in this standard.

In case of disagreement in assessing the level of mechanical properties, tests are carried out according to GOST 10006-80.

It is allowed to test the tensile strength of the base metal of pipes made of low-alloy steels in accordance with regulatory documentation approved in the prescribed manner.

(Changed edition, Amendment No. 4).

3.5. The tensile test of the welded joint must be carried out in accordance with GOST 6996-66 on type XII samples with the reinforcement removed. Samples for tensile testing of a welded joint are taken perpendicular to the seam.

perimeter - tape measure according to GOST 7502¾ 89;

length - using a tape measure in accordance with GOST 7502-89 or automated measuring instruments according to regulatory and technical documentation;

wall thickness - micrometer according to GOST 6507-90, wall gauge according to GOST 11358-89, thickness gauge according to GOST 11358-89;

Curvature - using a straight edge and a feeler gauge according to TU 2-034-225-87;

cutting bevel - this parameter is ensured by the design of equipment for processing pipe ends;

the depth of the defect at the cleaning site - with a depth gauge according to GOST 162-90;

the end ring at the ends of the pipes (blunting) - with a ruler according to GOST 427-75;

chamfer bevel angle - goniometer according to GOST 5378-88.

(Changed edition, Amendment No. 4).

3.12. Static bending testing of pipes is carried out according to regulatory and technical documentation.

3.10 - 3.12.(Introduced additionally, Amendment No. 2).

Electrically welded steel line-weld tubes. Technical requirements

GOST 10706-76

Date of introduction 01/01/78

This standard applies to straight-seam electric-welded pipes for general purposes with a diameter of 478–1420 mm.

1. TECHNICAL REQUIREMENTS

1.1. The dimensions of the pipes and the maximum deviations for them must comply with GOST 10704.

1.2. Depending on the quality indicators, pipes are manufactured into the following groups:

A - according to mechanical properties of carbon steel grades St2, St3 (all degrees of deoxidation) according to GOST 380, category 1 according to GOST 14637;

B - according to the chemical composition of carbon steel grades St2, St3 (all degrees of deoxidation) with a chemical composition in accordance with GOST 380 and GOST 14637;

B - according to the chemical composition and mechanical properties of carbon steel grades St2 (all degrees of deoxidation) according to GOST 380, category 2 according to GOST 14637, St3kp according to GOST 380, categories 2 and 3 according to GOST 14637, St3ps, St3sp according to GOST 380, categories 2, 3, 4 and 5 according to GOST 14637, as well as low-alloy steel, the carbon equivalent of which does not exceed 0.48%;

D - without standardization of mechanical properties and chemical composition, but with standardization of hydraulic test pressure.

(Changed edition, Amendment No. 4).

1.3. (Excluded, Amendment No. 3).

1.4. The mechanical properties of the base metal of the pipes must comply with the standards specified in table. 2.

Table 2*

(Changed edition, Amendment No. 4).

1.5. Groups of pipes A and B must withstand tensile mechanical tests of the welded joint in accordance with GOST 6996. The tensile strength of the welded joint must not be lower than the tensile strength of the base metal established for pipes made of this steel grade.

1.6. At the request of the consumer, group B pipes must withstand the impact strength test of the base metal. The impact strength standards of the base metal must correspond to those indicated in the table. 3.

Table 3

Note: By agreement between the manufacturer and the consumer, the impact strength of the base metal of low-alloy steel pipes at minus 60 °C must be at least 2.5 kgf. m/cm2 (0.24 MJ/m2).

For main heating networks, pipes are made heat-treated from steel grades St3sp4, St3sp5 with mechanical properties specified in table. 3a.

Table 3a

The standards for impact strength of a welded joint of pipes for heating networks at a temperature of minus 20°C must not be lower than the standards for the base metal given in Table. 3a.

The standards for impact strength after mechanical aging for the base metal of pipes and at minus 20°C for a welded joint are optional until July 1, 1988.

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

* Table 1. (Deleted, Amendment No. 3).

1.7. Pipes with a diameter of up to 820 mm must have no more than one longitudinal and one transverse seam. Pipes with a diameter of 820 mm or more must have two longitudinal and one transverse seam. At the request of the consumer, an increase in the number of transverse seams is allowed.

If there is a transverse seam, the longitudinal seams must be offset from one another by a distance of at least 100 mm. At the request of the consumer, the upper limit of the displacement of longitudinal seams relative to each other is established.

1.8. The height of the reinforcement bead for external longitudinal and transverse seams must correspond to the standards specified in table. 4.

Table 4

In places where seams and tacks are repaired, it is allowed to increase the height of the reinforcement roller by 1 mm above the norms specified in the table. 4.

The height of the reinforcement bead in the center of the internal seam must be at least 0.5 mm. It is allowed at the ends of pipes over a length of at least 150 mm to remove the reinforcement of the internal seam to a height of 0-0.5 mm.

(Changed edition, Amendment No. 4).

1.9. The ends of the pipes must be cut at right angles. The deviation from the right angle (cosine cut) should not exceed that indicated in the table. 5.

Table 5

1.10. The ends of the pipes should be chamfered at an angle of 25-30° to the end of the pipe. In this case, an end ring (blunt) with a width of 1.0–3.0 mm for pipes with a diameter of up to 1020 mm inclusive and a width of 1.0–5.0 mm for pipes with a diameter of more than 1020 mm should be left.

At the consumer's request, the bevel angle should be 30-35°, and for pipes with a wall thickness of 17 mm or more, the edges should be cut in accordance with the drawing. 1.

It is allowed to cut edges in accordance with the drawing. 1 is carried out on pipes with a wall thickness of 15 mm.

1.9, 1.10. (Changed edition, Amendment No. 4).

1.11. Cracks, stains, cavities, delaminations and sunsets on the surface of pipes are not allowed. Minor nicks, ripples, dents, small scratches, a thin layer of scale, traces

Cleaning and welding of defects is allowed if they do not bring the wall thickness beyond the maximum deviations. In addition, a longitudinal mark with a depth of no more than 0.2 mm is allowed, applied during automatic welding to guide the seam.

It is allowed to weld pipe defects with subsequent cleaning of the welding site and re-testing with hydraulic pressure.

1.12. Surface defects of the weld metal in the form of pores, cavities, cracks, fistulas and other defects that reduce the density and strength of the weld metal below the level of the base metal are not allowed.

Traces of metal shrinkage along the longitudinal axis of the seam (sink) are allowed. In this case, the amount of shrinkage should not bring the reinforcement height beyond the permissible minimum seam height.

The transition from the weld reinforcement to the base metal should be smooth (without undercuts).

Undercuts up to 0.5 mm deep are allowed without repair. If the undercuts on the outer and inner seams coincide, one of them must be repaired.

It is allowed to repair welded pipes followed by testing them with hydraulic pressure or monitoring the repair site using physical methods.

1.13. Each pipe must withstand the hydraulic pressure test.

Pipes of group A are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845 (P:), while the permissible stress is taken equal to 0.5 of the minimum tensile strength value established for a given steel grade.

According to the customer's order, the permissible stress should be equal to 0.85 of the minimum value of the yield strength.

Pipes of group B are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845 (P:), with a permissible stress equal to 0.9 of the minimum yield strength established for a given steel grade.

Pipes of groups D and B must withstand a hydraulic pressure test of at least 25 kgf/cm2 (2.5 MPa). Pipes with sizes 920 7, 1020 8, 11208, 11209, 12209, 1220 10, 13209, 1320 10, 1320 11, 1420 10 and 1420 11 mm are tested under a pressure of 20 kgf/cm 2 (2.0 MPa).

When testing on presses of various designs with axial support, the value of hydraulic pressure is determined in accordance with the requirements of GOST 3845.

Pipes longer than 10 m, obtained by joining, or more than two pipes that have passed hydrotests are not subject to hydrotesting. At the request of the consumer, the transverse weld must be controlled by non-destructive physical methods.

1.14. Welded seams of pipes for heating networks must be inspected using non-destructive methods along their entire length.

At the request of the consumer, welded joints of group B pipes must be controlled by non-destructive methods.

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

1.15. Welded joints of pipes for main heating networks must be subjected to static bending tests.

The minimum permissible bend angle for a welded joint of pipes made of carbon steel is at least 100°.

2. ACCEPTANCE RULES

2.1. Pipes are presented for acceptance in batches. The batch must consist of pipes of the same size, the same steel grade and the same manufacturing group and be accompanied by one quality document in accordance with GOST 10692.

The number of pipes in a batch should not exceed 100 pieces.

2.2. Each pipe is inspected and measured.

2.3. Each pipe is subjected to hydraulic pressure testing.

2.4. To control the mechanical properties and impact strength, the following are selected from the batch:

for single-seam pipes - two pipes;

for double-seam pipes - one pipe.

(Changed edition, Amendment No. 4).

2.5. The chemical composition of steel is accepted according to the document on the quality of the manufacturer of the workpiece. If necessary, the chemical composition of finished pipes is checked on one pipe from the batch.

2.6. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double sample taken from the same batch or melt.

The results of repeated tests apply to the entire batch.

(Changed edition, Amendment No. 2).

3. TEST METHODS

3.1. The chemical composition of steel is checked, if necessary, according to GOST 22536.0 - GOST 22536.6. Samples to determine the chemical composition of steel are taken according to GOST 7565.

3.2. The outer diameter of the pipes (D H) in millimeters is checked by measuring the perimeter and calculated using the formula:

where P is the perimeter of the cross-section of the pipe, mm;

Ar—thickness of the tape measure, mm;

0.2 - error when measuring the perimeter due to the skew of the tape measure when the divisions are aligned.

(Changed edition, Amendment No. 1).

3.3. Hydraulic testing of pipes must be carried out in accordance with GOST 3845 with a pressure holding time of at least 10 s.

3.4. To conduct a tensile test of the base metal and the welded joint, one sample is cut out of each selected pipe. Samples are selected in accordance with GOST 7564.

Tensile testing of the base metal is carried out on five-fold transverse samples in accordance with GOST 10006.

Instead of tensile testing, it is allowed to inspect pipes using non-destructive methods that ensure compliance of mechanical properties with the standards specified in this standard.

In case of disagreement in assessing the level of mechanical properties, tests are carried out according to GOST 10006.

It is allowed to test the tensile strength of the base metal of pipes made of low-alloy steels in accordance with regulatory documentation approved in the prescribed manner.

(Changed edition, Amendment No. 4).

3.5. The tensile test of the welded joint must be carried out in accordance with GOST 6996 on type XII samples with the reinforcement removed. Samples for tensile testing of a welded joint are taken perpendicular to the seam.

3.6. To carry out the impact bending test, three samples of the base metal and three samples of the welded joint are cut from each selected pipe. To test the base metal for impact bending after mechanical aging, three additional samples are selected in accordance with GOST 9454.

Inspection of the base metal of pipes for impact bending is carried out on samples cut perpendicular to the pipe axis. Tests are carried out in accordance with GOST 9454 on samples of type I with a wall thickness of more than 10 mm and type 3 with a wall thickness of 10 mm or less.

Inspection of a welded joint for impact bending is carried out on samples of type VII with a wall thickness of 10 mm or less and type VI with a wall thickness of 11 mm or more in accordance with GOST 6996. An incision on impact samples is made along the fusion line of the last welded seam, perpendicular to the rolled metal surface.

The impact strength of the base metal and welded joint is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, it is allowed to reduce the impact strength by 4.9 J/cm 2 (0.5 kgf. m/cm 2), except for pipes intended for heating networks.

(Changed edition, Amendment No. 2).

3.7. When making samples for mechanical testing, it is allowed to straighten samples using a static load.

3.8. The method and methodology for controlling the quality of a weld by physical methods are established by the manufacturer.

The standards for permissible defects determined by non-destructive testing methods are established by regulatory documentation approved in the prescribed manner.

3.9. The carbon equivalent for a single melt of low-alloy steel (E) as a percentage is calculated using the formula:

where C, Mn, V is the mass fraction of carbon, manganese and vanadium, %.

(Introduced additionally, Amendment No. 1).

3.10. The test for susceptibility to mechanical aging must be carried out according to GOST 7268 without preliminary 10% deformation.

(Introduced additionally, Amendment No. 2).

3.11. The following is measured on the pipe: perimeter - with a tape measure according to GOST 7502;

length - using a tape measure in accordance with GOST 7502 or automated measuring instruments according to regulatory documentation;

wall thickness - with a micrometer according to GOST 6507, thickness gauge according to GOST 11358;

curvature - using a straight edge and a feeler gauge according to the regulatory document;

cutting bevel - this parameter is ensured by the design of the equipment for processing ends

the depth of the defect at the cleaning site - with a depth gauge in accordance with GOST 162; the end ring at the ends of the pipes (blunting) - with a ruler in accordance with GOST 427; chamfer angle - with a protractor in accordance with GOST 5378.

(Changed edition, Amendment No. 2, 4).

3.12. Static bending testing of pipes is carried out according to regulatory documentation.

3.12 (Introduced additionally, Amendment No. 2).

4. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

4.1. Labeling, packaging, transportation and storage of pipes - in accordance with GOST 10692.

For mechanized branding, it is allowed to place marks at a distance of more than 500 mm from the end of the pipe. The branding area is marked with black paint in the form of an arrow or a straight line.

When marking on each pipe, additionally indicate:

• pipe number;
• batch number;
• Year of manufacture;
• brand technical control;
• pipe size (diameter and wall thickness);
• designation of this standard.

When marking pipes, it is allowed to apply it instead of the steel grade symbol, which is indicated in the quality document.

Pipes that have undergone heat treatment are branded with the “T” mark.

(Changed edition, Amendment No. 2).

APPLICATION. (Deleted, Amendment No. 3).

INFORMATION DATA

1. DEVELOPED by the All-Union Scientific Research, Design and Technological Institute of Pipe Industry (VNITI)

DEVELOPERS

O. A. Semenov, M. M. Bernshtein, N. F. Kuzenko

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated April 22, 1976 No. 892

Change No. 4 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 12 of November 21, 1997)

Registered by the Technical Secretariat of the IGU No. 2893

3. INSTEAD GOST 10706-63

4. The standard corresponds to ST SEV 489-77 and sets more stringent requirements for the impact strength of the base metal, the number of transverse seams, reinforcement of the internal seam, and the chamfer at the end of the pipe

5. The standard is unified with BDS 6120-66

6. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

7. The validity period was lifted according to Protocol No. 5-94 of the Interstate Council for Standardization, Metrology and Certification (IUS 11-12-94)

8. EDITION with Amendments No. 1, 2, 3, 4, approved in July 1980, December 1985, November 1990, April 1999 (IuS 10-80, 4-86, 2-91, 7 -99)

STATE STANDARD

USSR UNION

TECHNICAL REQUIREMENTS

GOST 10706-76 (ST SEV 489-77)

Official publication

PUBLISHING HOUSE OF STANDARDS Moscow

UDC 669.14-462.3:006.354 Group B62

STATE STANDARD OF THE USSR UNION

ELECTRIC-WELDED STRAIGHT-WELMED STEEL PIPES

Technical requirements

Electrically welded steel line-weld tubes. Technical requirements

(CT SEV 489-77)

Valid from 01/01/78

This standard applies to straight-seam electric welded pipes for general purposes with a diameter of 426-1620 mm.

The standard corresponds to ST SEV 489-77 and sets more stringent requirements for the impact strength of the base metal, the number of transverse seams, reinforcement of the internal seam, and the chamfer at the end of the pipe.

U TECHNICAL REQUIREMENTS

1.1. The dimensions of the pipes and the maximum deviations for them must comply with GOST 10704-91.

1.2. Depending on the quality indicators, pipes are manufactured into the following groups:

A-by mechanical properties from carbon steel grades St2, StZ (all degrees of deoxidation) category 1 according to GOST 14637-89;

B - according to the chemical composition of carbon steel grades St2, StZ, (all degrees of deoxidation) with a chemical composition in accordance with GOST 14637-89;

B - according to the chemical composition and mechanical properties of carbon steel St2 (all degrees of deoxidation) category 2, StZkp categories 2 and 3, StZps, StZsp categories 2 and 5 according to GOST 14637-89;

Official publication Reproduction prohibited

(6) Standards Publishing House, 1976 © Standards Publishing House, 1993 Reprint with changes

D - without standardization of mechanical properties and chemical composition, but with normalization of hydraulic pressure. By agreement between the manufacturer and the consumer, it is allowed to manufacture pipes from low-alloy steel, while the carbon equivalent for pipes of groups B and C should not exceed 0.48%.

(Changed edition, Amendment No. 3).

1.3. (Deleted, Amendment No. 3).

Table 1

Note. The “+” sign means that the indicator is normalized, the “-ъ” sign means that the indicator is not normalized.

1.4. The mechanical properties of the base metal of carbon steel pipes must comply with the standards specified in table. 2.

table 2

The mechanical properties of low-alloy steel pipes must not be lower than the standards given in table. 2 for steel grade StZsp.

(Changed edition, Amendment No. 3).

1.5. Pipes of groups A and B must withstand mechanical tensile tests of the welded joint in accordance with GOST 6996-66. The tensile strength of the welded joint must not be lower than the tensile strength of the base metal established for pipes made of a given steel grade.

1.6. At the request of the consumer, group B pipes must withstand the impact strength test of the base metal. The impact strength standards of the base metal must correspond to those indicated in the table. 3.

Table 3

The standards of impact strength of pipes made of low-alloy steel must not be lower than the standards given in table. 3 for steel grade StZsp4.

For main heating networks, pipes are made heat-treated from steel grade StZsp 4, 5 with mechanical properties specified in table. Behind.

Table For

The standards for impact strength of a welded joint of pipes for heating networks at a temperature of minus 20°C must not be lower than the standards for the base metal given in Table. Behind.

The standards for impact strength after mechanical aging for the base metal of pipes and at minus 20°C for a welded joint are optional until July 1, 1988.

1.7. Pipes with a diameter of up to 820 mm must have no more than one longitudinal and one transverse seam. Pipes with a diameter of 820 mm or more can have two longitudinal and one transverse seam. At the request of the consumer, an increase in the number of transverse seams is allowed.

If there is a transverse seam, the longitudinal seams must be offset from one another by a distance of at least 100 mm. At the request of the consumer, an upper limit for the displacement of longitudinal seams relative to each other is established.

1.8. The height of the reinforcement bead for external longitudinal and transverse seams must comply with the standards specified in table. 4.

Table 4

On pipes welded by one-sided welding, the bead is allowed to sink to a depth of up to 10% of the pipe wall thickness with a smooth transition to the base metal. The thickness of the seam at the sinking point should be 10% higher than the minimum permissible wall thickness.

The size of the reinforcement bead in the center of the internal seam must be at least 0.5 mm.

It is allowed at the ends of pipes with a length of at least 150 mm to remove the reinforcement of the internal seam to a height of 0-0.5 mm.

(Changed edition, Amendment No. 1).

1.9. The ends of the pipes must be cut at right angles. The deviation from the right angle (cut bevel) should not exceed that indicated in the table. 5.

1.10. The ends of the pipes should be chamfered at an angle of 25-30° to the end of the pipe. In this case, an end ring (blunt) with a width of 1.0-3.0 mm should be left - for pipes with a diameter of up to 1020 mm inclusive, and a width of 1.0-5.0 mm - for pipes with a diameter of more than 1020 mm.

1.11. Cracks, stains, shells, delaminations and sunsets on the surface of pipes are not allowed.

Minor nicks, ripples, dents, small scratches, a thin layer of scale, traces of stripping and welding of defects are allowed if they do not take the wall thickness beyond the maximum deviations. In addition, a longitudinal mark with a depth of no more than 0.2 mm is allowed, applied during automatic welding to guide the seam.

It is allowed to weld pipe defects with subsequent cleaning of the welding site and re-testing with hydraulic pressure.

1.12. Surface defects of the weld metal in the form of pores, cavities, cracks, fistulas and other defects that reduce the density and strength of the weld metal below the level of the base metal are not allowed.

Traces of metal shrinkage along the longitudinal axis of the seam are allowed (tension;. In this case, the amount of shrinkage should not take the height of the reinforcement beyond the permissible minimum height of the seam.

The transition from the weld reinforcement to the base metal should be smooth (without undercuts).

Undercuts up to 0.5 mm deep are allowed without repair. If the undercuts on the outer and inner seams coincide, one of them must be repaired.

It is allowed to repair welded pipes followed by testing them with hydraulic pressure or monitoring the repair site using physical methods.

1.13. Each pipe must withstand the hydraulic pressure test.

Pipes of group A are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 (Pi), while the permissible stress is taken equal to 0.5 of the minimum tensile strength value established for a given steel grade.

According to the customer's order, the permissible stress should be equal to 0.85 of the minimum value of the yield strength.

Pipes of group B are subjected to hydraulic pressure testing, calculated according to the formula given in GOST 3845-75 (Pi), with a permissible stress equal to 0.9 of the minimum value of the yield strength established for a given steel grade.

Pipes of groups D and B must withstand a hydraulic pressure test of at least 25 kgf/cm2 (2.5 MPa). Pipes sizes 920X7, 1020x8, 1120x8, 1120X9, 1220X9, 1220X 10,

1320x9, 1320x10, 1320x 11, 1420x 10 and 1420X11 mm are tested under a pressure of 20 kgf/cm 2 (2.0 MPa).

Note. If the yield strength in steel intended for the manufacture of pipes is not regulated, the value of hydraulic pressure is determined according to the formula given in GOST 3845 "-75 (R,), with an allowable stress equal to 0.5 of the minimum tensile strength value established for this steel grades.

When testing on presses of various designs with axial support, the value of hydraulic pressure is determined in accordance with the requirements of GOST 3845-75.

Pipes longer than 10 m, obtained by joining, or more than two pipes that have passed hydrotests are not subject to hydrotesting. At the request of the consumer, the transverse weld must be controlled by non-destructive physical methods.

1.14. Welded seams of pipes for heating networks must be inspected using non-destructive methods along the entire length.

At the request of the consumer, welded joints of group B pipes must be controlled by non-destructive methods.

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

1.15. Welded joints of pipes for main heating networks must be subjected to static bending tests.

The minimum permissible bend angle for a welded joint of carbon steel pipes is at least 100°.

(Introduced additionally, Amendment No. 2).

2. ACCEPTANCE RULES

2.1. Pipes are presented for acceptance in batches. The batch must consist of pipes of the same size, the same steel grade and the same manufacturing group and be accompanied by one quality document in accordance with GOST 10692-80.

The number of pipes in a batch should not exceed 100 pieces.

(Changed edition, Amendment No. 2).

2.2. Each pipe is inspected and measured.

2.3. Each Pipe is subjected to hydraulic pressure testing.

2.4. To control the mechanical properties, the following are selected from the batch:

for single-seam pipes - two pipes;

for double-seam pipes - one pipe.

2.5. The chemical composition of steel is accepted according to the document on the quality of the enterprise - the manufacturer of the workpiece. If necessary, the chemical composition of finished pipes is checked on one pipe from the batch.

2.6. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double sample taken from the same batch or heat.

The results of repeated tests apply to the entire batch.

(Changed edition, Amendment No. 2).

3. TEST METHODS

3.1. The chemical composition of steel is checked, if necessary, according to GOST 22536.0-87, GOST 22536.1-88, GOST 22536.2-87, GOST 22536.3-88, GOST 22536.4-88, GOST 22536.5-87, GOST 22536.6-88. Samples to determine the chemical composition of steel are taken according to GOST 7565-81.

3.2, The outer diameter of the pipes (D n) in millimeters is checked by measuring the perimeter and calculated using the formula

where P is the perimeter of the cross-section of the pipe, mm;

Ar is the thickness of the tape measure, mm;

0.2 - error when measuring the perimeter due to the skew of the tape measure when the divisions are aligned.

(Changed edition, Amendment No. 1).

3.3. Hydraulic testing of pipes must be carried out in accordance with GOST 3845-75 with exposure under pressure for at least 10 s.

3.4. To conduct a tensile test of the base metal and welded joint, one image is cut out from each selected pipe. Samples are taken in accordance with GOST 7564-73.

Tensile testing of the base metal is carried out on five-fold transverse samples in accordance with GOST 10006-80.

Instead of tensile testing, it is allowed to inspect pipes using non-destructive methods that ensure compliance of mechanical properties with the standards specified in this standard.

In case of disagreement in assessing the level of mechanical properties, tests are carried out in accordance with GOST 10006-80.

3.5. The tensile test of the welded joint must be carried out in accordance with GOST 6996-66 on type XII samples with the reinforcement removed. Samples for tensile testing of a welded joint are taken perpendicular to the seam.

3.6. To carry out the impact bending test, three samples of the base metal and three samples of the welded joint are cut from each selected pipe. To test the base metal for impact bending after mechanical aging, three additional samples are taken in accordance with GOST 9454-78.

Inspection of the base metal of pipes for impact bending is carried out on samples cut perpendicular to the pipe axis. Tests are carried out in accordance with GOST 9454-78 on samples of type I with a wall thickness of more than 10 mm and type 3 with a thickness of 10 mm or less.

Inspection of a welded joint for impact bending is carried out on samples of type VII with a wall thickness of 10 mm or less and type VI with a wall thickness of 11 mm or more in accordance with GOST 6996-66. The notch on impact samples is made along the fusion line of the last welded seam, perpendicular to the rolling surface of the metal.

The impact strength of the base metal and welded joint is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, it is allowed to reduce the impact strength by 4.9 J/cm 2 (0.5 kgf-m/cm 2), except for pipes intended for heating networks.

(Changed edition, Rev., No. 2).

3.7. When making samples for mechanical testing, it is allowed to straighten samples using a static load.

3.8. The method and methodology for controlling the quality of a weld by physical methods are established by the manufacturer.

The standards for permissible defects determined by non-destructive testing methods are established by normative and technical documentation approved in the prescribed manner.

3.9. The carbon equivalent for a single melt of low-alloy steel (E) in percent is calculated using the formula

where C, Mn, V - mass fraction of carbon, manganese and vanadium, %.

(Introduced additionally, Amendment No. 1).

3.10. The test for susceptibility to mechanical aging must be carried out according to GOST 7268-82 without preliminary 10% deformation.

3.11. Measure on the pipe:

perimeter - with a tape measure according to GOST 7502-89;

length - using a tape measure in accordance with GOST 7502-89 or automated measuring instruments according to regulatory and technical documentation;

wall thickness - with a micrometer according to GOST 6507-90, wall gauge according to GOST 11358-89, thickness gauge according to GOST 11358-89;

Curvature - straight edge and feeler gauge according to TU 2-034-225-87;

cutting bevel - this parameter is ensured by the design of equipment for processing pipe ends;

the depth of the defect at the cleaning site - with a depth gauge according to GOST 162-90;

end ring at the ends of pipes (blunting) - with a ruler in accordance with GOST 427-75;

chamfer bevel angle - with a protractor according to GOST 5378-88.

3.3 2. Testing of pipes for static bending is carried out according to regulatory and technical documentation.

EVIL-3.12. (Introduced additionally, Amendment No. 2).

4. LABELING, PACKAGING, TRANSPORTATION AND STORAGE

4.1. Labeling, packaging, transportation and storage of pipes - in accordance with GOST 10692-80.

For mechanized branding, it is allowed to place marks at a distance of more than 500 mm from the end of the pipe. The branding area is marked with black paint in the form of an arrow-pointer or a straight line.

When marking on each pipe, additionally indicate:

a) pipe number;

b) batch number;

c) year of manufacture;

t Id GOST 10706-76

d) technical control mark;

e) pipe size (diameter and thickness c) designation of this standard. Allowed for pipe marking

instead of May they became NaiO"

establish its symbol, which is indicated in the quality document, g) t com<Т>,

past those

are branded ZIA"

INFORMATION DATA

1. DEVELOPED by the All-Union Scientific Research, Design and Technological Institute of Pipe Industry (VNITI)

DEVELOPERS

O. A. Semenov, M. M. Bernshtein, N. F. Kuzenko

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated April 22, 1976 No. 892

3. Instead of GOST 10706-63

4. The standard corresponds to ST SEV 489-77 and sets more stringent requirements for the impact strength of the base metal, the number of transverse seams, the reinforcement of the internal seam, and the chamfer at the end of the pipe.

5. The standard is unified with BDS 6120-66

6. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

S, 12 GOST 10706-76

Amendment No. 4 GOST 10706-76 Longitudinal electric-welded steel pipes. Technical requirements

Adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 12 of 11.21.97)

Registered by the Technical Secretariat of the IGU No. 2893

The introductory part should be presented in a new edition:

“This standard applies to straight-seam electric-welded pipes for general purposes with a diameter of 478-1420 mm.”

"1.2. Depending on the quality indicators, pipes are manufactured into the following groups:

A - according to the mechanical properties of carbon steel grades St2,

StZ (all degrees of deoxidation) according to GOST 380-94, category 1 according to GOST 14637-89;

B - according to the chemical composition of carbon steel grades St2, StZ (all degrees of deoxidation) with a chemical composition in accordance with GOST 380-94 and GOST 14637-89;

B - according to the chemical composition and mechanical properties of carbon steel grades St2 (all degrees of deoxidation) according to GOST 380-94, category 2 according to GOST 14637-89, StZkp according to GOST 380-94, categories 2 and 3 according to GOST 14637-89, StZps , StZsp in accordance with GOST 380-94, categories 2, 3, 4 and 5 in accordance with GOST 14637-89, as well as from low-alloy steel, the carbon equivalent of which does not exceed 0.48%;

D - without standardization of mechanical properties and chemical composition, but with standardization of hydraulic test pressure.

1.4. The mechanical properties of the base metal of the pipes must comply with the standards specified in table. 2.

Clause 1.6. Table 3 should be presented in a new edition:

Table 3

"Note. By agreement between the manufacturer and the consumer, the impact strength of the base metal of low-alloy steel pipes at minus 60 °C must be at least 2.5 kgf * m / cm 2 (0.24 MJ / m 2)";

delete the second paragraph.

Clause 1.8 shall be stated in a new edition:

"1.8. The height of the reinforcement bead for external longitudinal and transverse seams must comply with the standards specified in table. 4.

In places where seams and tacks are repaired, it is allowed to increase the height of the reinforcement roller by 1 mm above the norms specified in the table. 4.

The height of the reinforcement bead in the center of the internal seam must be at least 0.5 mm. It is allowed at the ends of pipes with a length of at least 150 mm to remove the reinforcement of the internal seam to a height of 0-0.5 mm.”

Clause 1.9. Table 5. Replace value: 426 with 478; delete the last column.

Add paragraph 1.10 with the following paragraph:

“At the consumer’s request, the bevel angle should be 30-35, and for pipes with a wall thickness of 17 mm or more, the cutting of the edges should be carried out in accordance with the drawing. 1.

It is allowed to cut edges in accordance with the drawing. 1 is carried out on pipes with a wall thickness of 15 mm.

Clause 1.13. Note deleted.

Clause 2.4. Replace the words: “mechanical properties” with “mechanical properties and impact strength”.

Add paragraph 3.4 with the following paragraph:

“It is allowed to test the tensile strength of the base metal of pipes made of low-alloy steels in accordance with regulatory documentation approved in the prescribed manner.”

Clause 3.11. Fourth paragraph. Delete the words: “wall gauge according to GOST 11951-82”.

(IUS No. 7 of 1999)

Editor T. 77. Shashina Technical editor N. S. Grishanova Proofreader V. I. Barentseva

Delivered to embankment 06/03/93 Lodp. in the oven 09.20.93 Uel. oven l. 0.93. Uel. cr.-ott. 0.93.

Academic ed. l. 0.70 Circulation 2166 copies. C 631

Order "Badge of Honor" Publishing house of standards, 107076, Moscow, Kolodezny lane, 14. Type "Moscow printer". Moscow, Lyalin lane, 6. Zak. 378

State standard 10706-76 section OKS “Cast iron and steel pipes” has been put into effect since 1978 instead of the expired document GOST 10706-63. Last changes introduced in June 2009, additional updating carried out in 2010. The scope of the standard is straight-seam electric-welded steel pipes for general purposes. The main content of the document is technical requirements to finished products, mechanical properties, classification depending on the composition of raw materials, parameters of permissible deviations, acceptance rules and testing methods for finished products.

Sale of steel pipes according to GOST 10706-76

Purchase a wholesale batch of straight-seam electric welded steel pipes according to GOST 10706-76 from the manufacturer you can in the ChelPipe warehouse complex. Finished products are sold on favorable price terms with a set of accompanying documentation provided. All products of the plant are tested in accordance with GOST requirements and fully comply with regulatory specifications. For more information, please call 8 800 23 45 005.

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