Welded steel pipes for water and gas pipelines, galvanized gost. Water and gas pipes (VGP): types, characteristics, application

INTERSTATE STANDARD

STEEL PIPES
WATER AND GAS

TECHNICAL CONDITIONS

Introduction date 01.01.77

This standard applies to non-galvanized and galvanized steel welded pipes with threaded or knurled 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 made according to the dimensions and weight given in table. one.

At the request of the consumer, 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) 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 off-gauge pipes.

Table 1

Conditional pass	Outside diameter	Pipe Wall Thickness			Weight of 1 m of pipes, kg
			ordinary	reinforced		ordinary	reinforced

table 2

Conditional pass	Outside diameter	Wall thickness	Weight of 1 m of pipes, kg
Notes: 1. For a thread made by knurling, a reduction in its inner diameter of up to 10% along the entire length of the thread is allowed on the pipe. 2. The mass of 1 m of pipes was calculated with a steel density of 7.85 g / cm 3. Galvanized pipes are 3% heavier than non-galvanized ones.

1.3. Limit deviations in pipe dimensions should not exceed those indicated in Table. 3.

Table 3

Pipe dimensions			Pipe dimensions	Limit deviations for manufacturing precision pipes
		elevated			elevated
			Outer diameter with nominal bore:
			over 40 mm
up to 40 mm incl.			Wall thickness
Notes: 1. The maximum deviation in the plus side along the wall thickness is limited by the maximum deviations in the mass of pipes. 2. Pipes of ordinary manufacturing accuracy are used for water pipes, gas pipelines and heating systems. Pipes of increased manufacturing accuracy 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, the maximum deviations in mass should not exceed:

7.5% - for the party;

10% - for a single pipe.

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

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

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

1.5 mm - with nominal bore over 20 mm.

1.6. Pipe threads can be long or short. Thread requirements must comply with those specified in table. 4.

Table 4

Conditional passage, mm		Thread length before run		Conditional passage, mm	Number of threads with conditional passage	Thread length before run
			short				short

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

Legend Examples

Ordinary pipe, non-galvanized, of the usual manufacturing accuracy, random length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without thread and without a coupling:

The same with the clutch:

The same, measured length, threaded:

The same, zinc coated, random length, threaded:

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

For pipes for thread rolling, the letter H is indicated after the word "pipe" in the symbol.

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

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

(Revised edition, Rev. No. 1).

2. TECHNICAL REQUIREMENTS

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

Pipes for parts of water and gas pipeline structures are made of steel according to GOST 1050.

2.2. At the request of the consumer, the ends of the 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 with a width of 1 - 3 mm should be left.

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

2.1; 2.2.

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

(Revised edition, Rev. No. 3).

2.4. Cracks, captivity, swelling and sunsets are not allowed on the surface of the pipes.

At the ends of the pipes, delamination is not allowed.

Separate dents, ripples, risks, traces of stripping and other defects due to the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a scale layer 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 weld site if there is a gentle thickening of the inner diameter of not more than 1.0 mm in this place.

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

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more, on the inner surface of the pipe seam, the burr must be cut or flattened, while 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, made by the method of furnace welding and the method of hot reduction, a gentle thickening of a height of not more than 0.5 mm is allowed on the inner surface of the pipes in the weld zone.

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

2.6. Pipe ends must be cut square. The value of the bevel of the end is allowed no more than 2 °. Burr residues 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, made by furnace welding.

(Changed edition, Rev. 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, blistering and foreign inclusions (hardzinc, oxides, sintered charge), peeling of the coating from the base metal are not allowed.

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

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

(Changed edition, Rev. 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 a hydraulic pressure of 4.9 MPa (50 kgf / cm 2)

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

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

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

for pipes with nominal bore from 15 to 50 mm - not less than 7%;

for pipes with a nominal bore of 65 or more - at least 4%.

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

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

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

2.11. The pipe thread must be clean, without flaws and 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, Rev. No. 3, 4).

2.12. In the place of the seam, blackness on the threads of the thread is allowed if the decrease 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 broken (for cut) or incomplete (for knurled) 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, Rev. No. 2, 3, 5).

2.13. It is allowed on the thread to reduce the useful length of the thread (without run-off) up to 15% compared to that indicated in Table. 4, and at the request of the consumer up to 10%.

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

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

2.15. (Deleted, Rev. No. 3).

2.16. At the request of the consumer, welded seams of pipes are subjected to control by non-destructive methods.

(Revised edition, Rev. 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 with an addition for pipes intended for the manufacture of parts for water 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 manufacturer of the workpiece.

The mass of the party is not more than 60 tons.

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

3.2. The surface, dimensions and curvature are checked for each pipe of the batch.

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

* On the territory of the Russian Federation, GOST R 50779.71-99 applies.

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

(Changed edition, Rev. 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, 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 lot are selected, and for pipes manufactured by continuous furnace welding, two pipes per lot.

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

3.4. All pipes are subjected to mass control.

(Revised edition, Rev. No. 3).

3.5. Each pipe is subjected to a hydraulic pressure test. With 100% quality control of the weld by 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.

(Revised edition, Rev. 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 are taken from the lot.

(Revised edition, Rev. No. 2).

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

The retest results apply to the entire lot.

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 by non-destructive methods.

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

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

4.3. Hydraulic testing is carried out in accordance with GOST 3845 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.

(Revised edition, Rev. No. 3).

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

The test can be carried out on a mandrel with a taper angle of 30°.

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

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

(Revised edition, Rev. No. 3).

4.4c. The control of the weld is carried out by non-destructive methods according to the normative and technical documentation.

(Introducedadditionally, ch. No. 3).

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

4.6. The thread is checked with threaded ring gauges according to GOST 2533 (third class of accuracy).

In this case, the screwing of the non-going gauge-ring on the thread should be no more than three turns.

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

4.7. The curvature of the pipes is controlled by a straightedge according to GOST 8026 and a set of probes according to NTD.

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

4.8. The right angle of the ends of the pipes is controlled by a 90 ° square with a size of 160x100 mm class 3 GOST 3749, plate probes of set 4 according to NTD or a goniometer

Water-supply and gas-supply steel pipes. Specifications

GOST 3262-75

OKP 13 8500, OKP 13 8501

Introduction date 01.01.77

This standard applies to non-galvanized and galvanized steel welded pipes with threaded or knurled 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, Rev. No. 2, 3, 5).

1. ASSORTMENT

1.1. Pipes are made according to the dimensions and weight given in table. one.

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

(Changed edition, Rev. 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 off-gauge pipes.

Table 1

Table 2

N o t e s:

1. For a thread made by knurling, a reduction in its inner diameter of up to 10% along the entire length of the thread is allowed on the pipe.

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

1.3. Limit deviations in pipe dimensions should not exceed those indicated in Table. 3.

Table 3

N o t e s:

1. The maximum deviation in the plus side along the wall thickness is limited by the maximum deviations in the mass of pipes.

2. Pipes of ordinary manufacturing accuracy are used for water pipes, gas pipelines and heating systems. Pipes of increased manufacturing accuracy 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, the maximum deviations in mass should not exceed:

7.5% - for the party;

10% - for a single pipe.

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

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

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

1.5 mm - with nominal bore over 20 mm.

1.6. Pipe threads can be long or short. Thread requirements must comply with those specified in table. 4.

Table 4

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

EXAMPLES OF CONVENTIONS

Ordinary pipe, non-galvanized, of the usual manufacturing accuracy, random length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without thread and without a coupling:

Pipe 20 -2.8 TOAST 3262-75

The same with the clutch:

Pipe M-20 -2.8 TOST 3262-75

The same, measured length, threaded:

Pipe R-20 2.8-4000 TOST 3262-75

The same, zinc coated, random length, threaded:

Pipe Ts-R-20 -2.8 TOST 3262-75

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

Pipe Ts-R-20 -2.8-4000 TOST 3262-75

For pipes for thread rolling, the letter H is indicated after the word "pipe" in the symbol.

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

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

(Revised edition, Rev. No. 1).

2. TECHNICAL REQUIREMENTS

2.1. Pipes are manufactured in accordance with the requirements of this standard and according to the 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 and gas pipeline structures are made of steel according to 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 with a width of 1-3 mm should be left.

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

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

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

(Revised edition, Rev. No. 3).

2.4. Cracks, captivity, swelling and sunsets are not allowed on the surface of the pipes.

At the ends of the pipes, delamination is not allowed.

Separate dents, ripples, risks, traces of stripping and other defects due to the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a scale layer 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 weld site if there is a gentle thickening of the inner diameter of not more than 1.0 mm in this place.

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

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

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, made by the method of furnace welding and the method of hot reduction, a gentle thickening of a height of not more than 0.5 mm is allowed on the inner surface of the pipes in the weld zone.

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

2.6. Pipe ends must be cut square. The value of the bevel of the end face is not more than 2°. Burr residues 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, made by furnace welding.

(Changed edition, Rev. 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, blistering and foreign inclusions (hardzinc, oxides, sintered charge), peeling of the coating from the base metal are not allowed.

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

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

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

2.8. Pipes must withstand hydraulic pressure:

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

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

At the request of the consumer, the pipes must withstand a hydraulic pressure of 4.9 MPa (50 kgf / cm 2).

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

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

for pipes with nominal bore from 15 to 50 mm - not less than 7%;

for pipes with a nominal bore of 65 mm or more - at least 4%.

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

2.8, 2.9. (Changed edition, Rev. 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. The pipe thread must be clean, without flaws and 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, Rev. No. 3, 4).

2.12. In the place of the seam, blackness on the threads of the thread is allowed if the decrease 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 stripped (for cut) or incomplete (for knurled) 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. It is allowed on the thread to reduce the useful length of the thread (without run-off) 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, Rev. No. 2, 3, 5).

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

2.15. (Deleted, Rev. No. 3).

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

(Revised edition, Rev. No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, one brand steel 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 and gas pipeline structures, made of steel in accordance with GOST 1050; chemical composition and mechanical properties of steel - in accordance with the document on the quality of the enterprise - the manufacturer of the workpiece.

Party weight - no more than 60 tons.

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

3.2. The surface, dimensions and curvature are checked for each pipe of the batch.

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

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

(Changed edition, Rev. 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, burr residues, right angle and chamfer angle (for pipes with bevelled 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 from the batch.

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

3.4. All pipes are subjected to mass control.

(Revised edition, Rev. No. 3).

3.5. Each pipe is subjected to a hydraulic pressure test. With 100% quality control of the weld by 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.

(Revised edition, Rev. 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 are taken from the lot.

(Revised edition, Rev. No. 2).

3.7. Upon receipt of unsatisfactory test results for at least one of the indicators, it is repeated tests on a double sample.

The retest results apply to the entire lot.

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 surface of the pipes is carried out visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845 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.

(Revised edition, Rev. No. 3).

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

The test can be carried out on a mandrel with a taper angle of 30°.

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

4.46. The flattening test is carried out according to GOST 8695.

(Revised edition, Rev. No. 3).

4.4c. Weld seam control is carried out by non-destructive methods according to normative documentation.

(Introduced additionally, 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 in accordance with GOST 9.301 and GOST 9.302, as well as with devices of the MT-41NTs, MTZON types or the Impulse type according to regulatory documentation.

4.6. The thread is checked with threaded ring gauges according to GOST 2533 (third class of accuracy).

In this case, the screwing of the non-going gauge-ring on the thread should be no more than three turns.

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

4.7. The curvature of the pipes is controlled by a straightedge in accordance with GOST 8026 and a set of probes according to ND.

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

4.8. The right angle of the ends of the pipes is controlled by a 90 ° square with a size of 160 100 mm of class 3 according to GOST 3749, plate probes of set 4 according to ND or a goniometer according to GOST 5378. The bevel angle is controlled by a goniometer according to GOST 5378.

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

4.9. The control of the outer diameter is carried out with smooth micrometers in accordance with GOST 6507, with staple gauges in accordance with GOST 2216 or GOST 18360.

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

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

The control of the mass of a batch of pipes is carried out on scales of not more than 10 tons with a division value of not more than 20 kg.

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

4.10. Weld seam control is carried out by non-destructive methods according to technical documentation.

(Introduced additionally, Rev. No. 4).

5. MARKING, PACKAGING, TRANSPORT AND STORAGE

5.1. Marking, packaging, transportation and storage are carried out in accordance with GOST 10692 with an addition.

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

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

INFORMATION DATA

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

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

2. APPROVED AND INTRODUCED BY Decree of the USSR State Committee for Standards dated 11.09.75 No. 2379

3. Periodicity of inspection - 5 years

4. REPLACE GOST 3262-62

5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

6. The validity period was removed by the Decree of the State Standard of November 12, 1991 No. 1726

7. EDITION with Amendments No. 1, 2, 3, 4, 5, 6, approved January 1987, May 1988, November 1989, November 1991 2-90, 2-92)

On the territory of the Russian Federation, GOST R 50779.71-99 applies.

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 operated in open areas, they install pipelines for transporting liquid and gaseous media. Such steel pipes are practically indispensable in the field of capital and private construction, housing and communal services, and agriculture.

You can get acquainted with the GOST requirements for steel water and gas pipes by downloading the document in pdf format from 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 the intended purpose, as their name indicates. The differences between their types are 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 stipulated by the provisions of such a document as GOST 3262 (75, 80, 85, 91).

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

• non-galvanized;
• galvanized;
• originally made with threaded ends, which can be obtained by cutting or knurling;
• without carving.

Applications and individual parameters

The main areas of application for water and gas pipes, the geometric parameters and technical characteristics of which comply with the 3262-75 standard, are construction and repair. Pipes of this category are used for arranging gas, water communications and heating systems in cottages and multi-apartment buildings, office 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 measured, multiple measured and random 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 that is within the measured value.

The 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 the 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 customer determines the version of their design and the length of the cut. So, the most popular are pipes, at the ends of which threads are cut during the production process. The reason for their high popularity lies in the fact that they do not require welding operations for their installation.

The thread on VGP pipes can be created during their production:

• knurling (a technology that allows you to get a thread with the most accurate parameters, while it is assumed that the inner diameter of the pipe will be 10% less);
• cutting.

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 mass 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 restriction on deviations in batch weight: they should not exceed 8%.

Technical requirements

A range is formed from pipes of each type, in which their geometric parameters and theoretical weight are listed.

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

Welded

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

1. If tubular products are connected using furnace welding technology, then in the area of ​​\u200b\u200bthe weld, their outer diameter can be reduced by half a millimeter. If there is a gentle thickening on the inside of the seam, its value should not exceed 1 mm.
2. If by welding it is necessary to connect water and gas pipes, the wall thickness of which is more than 5 mm, then chamfers must be removed at their ends 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 weld seam of water and gas pipes, the diameter of which exceeds 20 mm, the 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 through diameter of more than 15 mm, produced using hot reduction (drawing) technology and connected by furnace welding. According to such requirements, a gentle thickening may be present on the inside of the weld, the height of which is not 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 thread formed at the ends of water and gas pipes in the factory must correspond to the accuracy category "B". Its characteristics are stipulated by the provisions of GOST 6357. So, the thread must be clean, it cannot have flaws and burrs.
2. At the joints, on the threads, blackness is possible, while 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. Useful thread length (specified in the assortment and measured without run-out) can be reduced up to 15%, but the customer has the right to reduce this deviation to 10%.

Galvanized

1. The zinc layer, which is applied to the entire surface of the water and gas pipe at the factory, must have a thickness of at least 30 microns. At the same time, it is assumed that in the areas with threaded threads and on the ends, the zinc coating may be absent.
2. The zinc film must be applied with high quality, it must not have blistering, delamination from the base metal and foreign inclusions (oxides, sintered charge, zinc waste, etc.).
3. In GOST, the presence of flux spots on the surface of galvanized pipes, small influxes of zinc, roughness and traces left by elements of lifting devices is allowed.
4. If sections not covered with zinc are found on water and gas pipes, then they can be re-treated - provided that the total area of ​​such sections does not exceed 0.5% of the entire surface area of ​​\u200b\u200bthe given product.

without zinc coating

1. The customer can discuss with the manufacturer the complete set of state-of-the-art 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. On the surface of water and gas pipes, there may be individual defects that are due to the production method (ripples, risks, dents, traces of stripping). At the same time, such defects should not reduce the pipe wall thickness below the tolerance specified in the assortment. A layer of scale may also be present, but it should not interfere with the inspection of the product.
4. The ends of the water and gas pipes sold to the consumer are cut at a right angle. The bevel, if it occurs during trimming, 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 pipeline category are mandatory:

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

Date of introduction 01.01.1977

This standard applies to non-galvanized and galvanized steel welded pipes with threaded or knurled 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 made according to the dimensions and weight given in table. one.

At the request of the consumer, 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:

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 off-gauge pipes.

Table 1

Conditional pass	Outside diameter	Wall thickness			Weight 1 meter, kg
		lungs	ordinary	reinforced	lungs	ordinary	reinforced
6	10,2	1,8	2,0	2,5	0,37	0,40	0,47
8	13,5	2,0	2,2	2,8	0,57	0,61	0,74
10	17,0	2,0	2,2	2,8	0,74	0,80	0,98
15	21,3	2,35	-	-	1,10	-	-
15	21,3	2,5	2,8	3,2	1,16	1,28	1,43
20	26,8	2,35	-	-	1,42	-	-
20	26,8	2,5	2,8	3,2	1,50	1,66	1,86
25	33,5	2,8	3,2	4,0	2,12	2,39	2,91
32	42,3	2,8	3,2	4,0	2,73	3,09	3,78
40	48	3,0	3,5	4,0	3,33	3,84	4,34
50	60	3,0	3,5	4,0	4,22	4,88	6,16
65	75,5	3,2	3,5	4,0	5,71	7,05	7,88
80	88,5	3,5	4,0	4,5	7,34	8,34	9,32
90	101,3	3,5	4,0	4,5	8,44	9,60	10,74
100	114	4,0	4,5	5	10,85	12,15	13,44
125	140	4,0	4,5	5,5	13,42	15,04	18,24
150	165	4,0	4,5	5,5	15,88	17,81	21,63

table 2

Conditional pass Outside diameter Wall thickness Weight 1 m, kg 10 16 2,0 0,69 15 20 2,5 1,08 20 26 2,5 1,45 25 32 2,8 2,02 32 41 2,8 2,64 40 47 3,0 3,26 50 59 3,0 4,14 65 74 3,2 5,59

For a thread made by knurling, a reduction in its inner diameter of up to 10% along the entire length of the thread is allowed on the pipe. The mass of 1 m of pipes is calculated with a steel density of 7.85 g/cm3. Galvanized pipes are 3% heavier than non-galvanized ones.

1.3. Limit deviations in pipe dimensions should not exceed those indicated in Table. 3.

Table 3

1. The maximum deviation in the plus side along the wall thickness is limited by the maximum deviations in the mass of pipes.
2. Pipes of ordinary manufacturing accuracy are used for water pipes, gas pipelines and heating systems. Pipes of increased manufacturing accuracy 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, the maximum deviations in mass should not exceed:

7.5% - for the party;
+ 10% - for a separate pipe.

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

2 mm - with nominal bore up to 20 mm inclusive;
1.5 mm - with nominal bore over 20 mm.

1.6. Pipe threads can be long or short. Thread requirements must comply with those specified in table. 4.

Table 4

Conditional pass	Number of threads with conditional passage	Thread length to the run, mm
		long	short
6	-	-	-
8	-	-	-
10	-	-	-
15	14	14	9
20	14	16	10,5
25	11	18	11
32	11	20	13
40	11	22	15
50	11	24	17
65	11	27	19,5
80	11	30	22
90	11	33	26
100	11	36	30
125	11	38	33
150	14	42	36

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

Legend Examples

Ordinary pipe, non-galvanized, of the usual manufacturing accuracy, random length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without thread and without a coupling:
Pipe 20x2.8 GOST 3262-75

The same with the clutch:
Pipe M-20x2.8 GOST 3262-75

The same, measured length, threaded:
Pipe R-20x2.8-4000 GOST 3262-75

The same, zinc coated, random length, threaded:
Pipe Ts-R-20x2.8 GOST 3262-75

The same, with zinc coating, measured length, with thread:
Pipe Ts-R-20x2.8-4000 GOST 3262-75

For pipes for thread rolling, the letter H is indicated after the word "pipe" in the symbol.
For pipes with a long thread, the letter D is indicated after the word "pipe" in the symbol.
For pipes of increased manufacturing accuracy, the letter P is indicated in the symbol after the nominal bore size.

2. TECHNICAL REQUIREMENTS

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

Pipes for parts of water and gas pipeline structures are made of steel according to GOST 1050.

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

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

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

2.4. Cracks, captivity, swelling and sunsets are not allowed on the surface of the pipes.

At the ends of the pipes, delamination is not allowed.

Separate dents, ripples, risks, traces of stripping and other defects due to the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a scale layer 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 weld site if there is a gentle thickening of the inner diameter of not more than 1.0 mm in this place.

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more, on the inner surface of the pipe seam, the burr must be cut or flattened, while 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, made by the method of furnace welding and the method of hot reduction, a gentle thickening of a height of not more than 0.5 mm is allowed on the inner surface of the pipes in the weld zone.

2.6. Pipe ends must be cut square. The value of the bevel of the end is allowed no more than 2 °. Burr residues 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, made by furnace welding.

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, blistering and foreign inclusions (hardzinc, oxides, sintered charge), peeling of the coating from the base metal are not allowed.

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

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

2.8. Pipes must withstand hydraulic pressure:

2.4 MPa (25 kgf / cm 2) - ordinary and light pipes;
3.1 MPa (32 kgf / cm 2) - reinforced pipes.
At the request of the consumer, the pipes must withstand a hydraulic pressure of 4.9 MPa (50 kgf / cm 2).

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

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

for pipes with nominal bore from 15 to 50 mm - not less than 7%;
for pipes with a nominal bore of 65 mm or more - at least 4%.
At the request of the consumer, the pipes must withstand the flattening test up to a distance between the flattened surfaces equal to 2/3 of the outer diameter of the pipes.

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

2.11. The pipe thread must be clean, without flaws and burrs, and comply with GOST 6357, accuracy class B.

Pipes with cylindrical threads are used when assembling with seals.

2.12. In the place of the seam, blackness on the threads of the thread is allowed if the decrease 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 broken (for cut) or incomplete (for knurled) 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. It is allowed on the thread to reduce the useful length of the thread (without run-off) up to 15% compared to that indicated in Table. 4, and at the request of the consumer - up to 10%.

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

2.16. At the request of the consumer, welded seams of pipes are subjected to control by non-destructive methods.

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same steel 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 and gas pipeline structures, from steel in accordance with GOST 1050; chemical composition and mechanical properties of steel - in accordance with the document on the quality of the blank manufacturer.

Party weight - no more than 60 tons.

3.2. The surface, dimensions and curvature are checked for each pipe of the batch.

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

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

3.3. To control the parameters of the thread, to test for expansion, flattening, bending, the height of the internal burr, 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 lot are selected, and for pipes manufactured by continuous furnace welding, two pipes per lot.

3.4. All pipes are subjected to mass control.

3.5. Each pipe is subjected to a hydraulic pressure test. With 100% quality control of the weld by 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.

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

3.7. Upon receipt of unsatisfactory test results for at least one of the indicators, it is repeated tests on a double sample.

The retest results apply to the entire lot.

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 surface of the pipes is carried out visually.

4.3. Hydraulic testing is carried out in accordance with GOST 3845 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.

4.4-a. The expansion test is carried out according to GOST 8694 on a conical mandrel with a taper angle of 6°. The test can be carried out on a mandrel with a taper angle of 30°.
4.4-b. The flattening test is carried out according to GOST 8695.
4.4-in. Weld seam control is carried out by non-destructive methods according to normative documentation.

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

4.6. The thread is checked with threaded ring gauges according to GOST 2533 (third class of accuracy). In this case, the screwing of the non-going gauge-ring on the thread should be no more than three turns.

4.7. The curvature of the pipes is controlled by a straightedge according to GOST 8026 and a set of probes according to ND.

4.8. The right angle of the ends of the pipes is controlled by a 90 ° square with a size of 160 100 mm class 3 according to GOST 3749, plate probes of set 4 according to ND or a goniometer according to GOST 5378. The bevel angle of the chamfer is controlled by a goniometer according to GOST 5378.

4.9. The control of the outer diameter is carried out with smooth micrometers in accordance with GOST 6507, with staple gauges in accordance with GOST 2216 or GOST 18360.

The wall thickness, the height of the internal burr and the height of the burrs are measured with a micrometer according to GOST 6507 or a wall gauge according to GOST 11358 from both ends of the pipe. The length of the pipes is measured with a tape measure in accordance with GOST 7502. The thread is controlled with gauges in accordance with GOST 2533.

The control of the mass of a batch of pipes is carried out on scales of not more than 10 tons with a division value of not more than 20 kg.

4.10. Weld seam control is carried out by non-destructive methods according to technical documentation.

5. MARKING, PACKAGING, TRANSPORT AND STORAGE

5.1. Marking, packaging, transportation and storage are carried out in accordance with GOST 10692 with an addition.
5.1.1. Pipe threads must be protected from mechanical damage and corrosion by grease in accordance with regulatory documents.

Includes Changes No. 1, 2, 3, 4, 5, 6 approved January 1987, May 1988, November 1989, November 1991 2-90, 2-92)

Related articles:

Water and gas pipes belong to the class of steel pipes for special purposes. Distinguish products according to the method of manufacture. Dimensions and ratios are determined by GOST standards. Also, based on the needs of customers, they determine pipes with or without threads.

Welded steel products according to GOST 3262-75 are:

• non-galvanized;
• galvanized;
• threaded (cut or knurled);
• without carving.

Technical characteristics of steel gas pipes

Water and gas pipeline (VGP) products are used in the construction of industrial buildings, residential multi-apartment and private houses, office buildings, educational institutions and other facilities.

VGP pipes are used:

• cold water supply;
• heating system;
• gas pipeline

Steel welded products are cut in length within 4-12 m. The footage of pipes according to GOST can be:

• random (4-12 m) length;
• measured (4-8 m or 8-12 m) length.

Water and gas pipes are conditionally divided into groups according to wall parameters:

• lungs;
• reinforced;
• ordinary.

Light pipes

The ratio of the dimensions and weight of the products is different, depending on the diameter, wall thickness, steel grade, material processing method (galvanized, non-galvanized).

Table 1. Parameter grid for light steel pipes

Nominal passage dу (mm)	Side/wall thickness - S (mm)	Outside diameter - dH (mm)	Weight (1 m in kg)	Number of meters per ton Nt
6	1,8	10,2	0,37	2682
8	2,0	13,5	0,57	1763
10	2,0	17,0	0,74	1352
15	2,35	21,3	1,10	910,5
15	2,5	21,3	1,16	862,7
20	2,35	26,8	1,42	705,7
20	2,5	26,8	1,50	667,5
25	2,8	33,5	2,12	471,7
32	2,8	42,3	2,73	366,6
40	3,0	48,0	3,33	300,4
50	3,0	60,0	4,22	237,1
65	3,2	75,5	5,71	175,3
80	3,5	88,5	7,34	136,3
90	3,5	101,3	8,44	118,5
100	4,0	114,0	10,85	92,16
125	4,0	140,0	13,42	74,54
150	4,0	165,0	15,88	62,96

Ordinary pipes

Table 2. Metric data for ordinary GWP products

du (mm)	S(mm)	dH (mm)	Weight (1 m in kg)	Nt
6	2,0	10,2	0,40	2473
8	2,2	13,5	0,61	1631
10	2,2	17,0	0,80	1245
15	-	21,3	-	-
15	2,8	21,3	1,28	782
20	-	26,8	-	-
20	2,8	26,8	1,66	603,4
25	3,2	33,5	2,39	418,2
32	3,2	42,3	3,09	324,1
40	3,5	48,0	3,84	260,4
50	3,5	60,0	4,88	205,1
65	4,0	75,5	7,05	141,8
80	4,0	88,5	8,34	120,0
90	4,0	101,3	9,60	104,2
100	4,5	114,0	12,15	82,29
125	4,5	140,0	15,04	66,50
150	4,5	165,0	17,81	56,14

reinforced pipes

Reinforced pipes are distinguished by an increased wall thickness, and, accordingly, a greater weight of 1 running meter. Such products are used for water supply and transportation of gas under high pressure.

Table 3. Grid of parameters for reinforced steel products

6	2,5	10,2	0,47	2106
8	2,8	13,5	0,74	1353
10	2,8	17,0	0,98	1020
15	-	21,3	-	-
15	3,2	21,3	1,43	700,1
20	-	26,8	-	-
20	3,2	26,8	1,86	536,9
25	4,0	33,5	2,91	343,6
32	4,0	42,3	3,78	264,7
40	4,0	48,0	4,34	230,4
50	4,5	60,0	6,16	162,4
65	4,5	75,5	7,88	126,9
80	4,5	88,5	9,32	107,3
90	4,5	101,3	10,74	93,03
100	5,0	114,0	13,44	74,41
125	5,5	140,0	18,24	54,81
150	5,5	165,0	21,63	46,22

Threaded pipes

Steel pipes are manufactured by the factories according to the customer's order. Therefore, the dimensions: length, diameter, wall thickness, design, may be different. Threaded pipes are in great demand. The products are distinguished by a high price, but on the other hand, they are adapted for simple installation without welding.

The thread is determined by the method of execution:

1. The knurling method is the most reliable method, in which compliance with standards is taken into account to the smallest detail. Tolerances: 10% inner diameter reduction.
2. External threading on the product.

The thread is provided both long and short. The following requirements apply to it (table 5).

Table 5. Thread parameters for VGP pipes

du (mm)	Runaway size (mm)		Number of threads per pass
	short	long
6	-	-	-
8	-	-	-
10	-	-	-
15	9,0	14	14
20	10,5	16	14
25	11,0	18	11
32	13,0	20	11
40	15,0	22	11
50	17,0	24	11
65	19,5	27	11
80	20,0	30	11
90	26,0	33	11
100	30,0	36	11
125	33,0	38	11
150	36,0	42	-

Note that the listed types of pipes (reinforced, light, ordinary) after galvanizing become 3% heavier than ferrous metal products. But the limiting mass deviation parameter should not exceed more than 8% (for a batch - 10%) according to GOST.

Technical requirements for steel water and gas pipes

Gas pipes are manufactured exclusively in accordance with the above standards. The materials used for products are established by GOST 380 and 1050. This steel excludes mechanical and chemical impurities. Requirements for steel gas pipes are characterized according to the following principles: welded, threaded, galvanized, black.

Welded steel pipes

Requirements and tolerances according to GOST for welded steel pipes:

1. In places of seams - a decrease to 0.5 mm in diameter. Only when the product is made by furnace welding. And if in these places there is a gentle compaction along the inner diameter - up to 1 mm.
2. The ends of products that need to be welded with a wall thickness of 5 mm or more are chamfered with an angle of 35-40 degrees towards the end. The end ring must correspond to a width (volume) of 1-3 mm.
3. Pipes with dy from 20 mm on the surface of the inner wall must have a burr in a flattened or cut form. The height of this burr is not higher than 0.5 mm. With the same conditions, but with the parameters of a water and gas pipe with a passage of 15 mm and including production with the hot reduction method - thickening is not higher than 0.5 mm.

Threaded steel pipes

Tolerances and requirements for threaded steel products:

1. The thread of water and gas pipes is established by GOST 6357 (class B). Should be free of burrs or torn spots.
2. Blackness is allowed at the seams only in the threaded area with the following parameters: reduction of the thread height from the main norm - no more than 15%.
3. The thread length can be reduced up to 15% (without run-off), on request up to 10%.

Galvanized steel pipes

Requirements for galvanized steel pipes:

1. If gas pipes are made with zinc coating, then the layer thickness should be 30 microns (not less). But the coating may be absent on the threads and ends of the product.
2. The galvanized surface should not have bubbles, delaminations from the base material and various inclusions (oxides, mixtures, hard zinc).
3. The cover must be continuous.
4. Rare inaccuracies in the form of flux spots or traces of capture on the surface are allowed.
5. Allow correction (re-application) of non-galvanized areas in accordance with GOST 9307. In general, no more than 0.5% of the entire surface.

Non-galvanized (black) steel products

Requirements for non-galvanized steel pipes:

1. Couplings are manufactured according to the GOST standard: 8944, 8954, 8965 and 8966.
2. Cracks, sunsets, swellings or a film on the surface of the product are excluded.
3. Minor defects are allowed: traces of cleaning, scale layers, dents, risks, rowanness. But only if they do not increase the volume of the wall, going beyond the minimum norm, and do not interfere with viewing.
4. The ends of the VGP pipes are cut at a right angle. The size of the bevel is no more than two degrees, and the burrs are no higher than 0.5 mm.

The resistance of gas pipelines is checked according to the following indicators:

1. Hydraulic pressure holding:
   • for VGP of lungs and ordinary: 2.4 MPa (25 kgf/cm2);
   • for enhanced VGP: 3.1 MPa (32 kgf/cm2);
   • for products on special order: 4.9 MPa (50 kgf/cm2).
2. Bending test of gas pipeline products with different conditional passage (dy):
   • dy up to 40 mm - the radius of the surface diameter is 2.5;
   • dy up to 50 mm - surface diameter radius 3.5.
3. Distribution expertise:
   • dy 15 - 50 mm: not less than 7%;
   • dy from 65 mm: not less than 4%.

Marking of steel water and gas pipes

Conventional marking of a steel pipe includes information about the dimensions, quality of the material, method of processing and manufacturing. At the end of the designation, the GOST number is added, according to which the product is manufactured.

Principles of marking VGP pipes:

1. "20x2.8 GOST 3262-75" (hereinafter without specifying GOST and number). Deciphering the designation:
   • ordinary non-galvanized pipe;
   • wall thickness - 2.8 mm;
   • length - unmeasured;
   • dy - 20 mm (conditional pass);
   • without thread/coupling.
2. "M-20x2.8". Deciphering the designation:
   • non-galvanized ordinary;
   • wall thickness - 2.8 mm;
   • thread missing;
   • length - unmeasured;
   • dy - 20 mm;
   • with clutch.
3. "R-20x2.8-5000". Deciphering the designation:
   • non-galvanized ordinary;
   • wall thickness - 2.8 mm;
   • carving is present;
   • length - measured (5 m);
   • dy - 20 mm;
   • without clutch.
4. "Ts-R-20x2.8". Deciphering the designation:
   • galvanized ordinary;
   • wall thickness - 2.8 mm;
   • carving is present;
   • length - unmeasured;
   • dy - 20 mm;
   • without clutch.
5. "Ts-R-20x2.8-4000". Deciphering the designation:
   • galvanized ordinary;
   • wall thickness - 2.8 mm;
   • carving is present;
   • length - measured (4 m);
   • dy - 20 mm;
   • without clutch.

Note:

• the letter "H" denotes knurled pipes with threads;
• the letter "D" indicates products with a long thread;
• the letter "P" denotes VGP pipes with increased manufacturing accuracy.

Rules for storage, transportation, packaging of VGP steel pipes

Water and gas pipes do not have specific packaging requirements. Exceptions are products with d=6…20 mm. These gas pipeline products are packaged in coils at the request of the customer.

When transporting VGP pipes, it is necessary to adhere to the basic principle - the products are firmly fixed in order to eliminate losses.

Yulia Petrichenko, expert

Store gas pipes based on the properties of the material:

• if products with a galvanized surface, then it is enough to fix and cover from moisture. Although these pipes are characterized by increased anti-corrosion properties, in places free of zinc coating, rust may appear in high humidity;
• non-galvanized VGP products are stored in a dry place, excluding moisture penetration. Firmly fixed.

What pipes do you use for gas or water pipes? How do you transport, pack or store pipes? Leave interesting facts and useful information in the comments.