Pipes steel water and gas. Water and gas pipes (VGP): types, characteristics, application Non-galvanized steel pipe GOST

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
Conditional pass	Outside diameter		ordinary	enhanced		ordinary	enhanced

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
Pipe dimensions	elevated	Pipe dimensions		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
Conditional passage, mm		short	Conditional passage, mm	Number of threads with conditional passage		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).

At the request of the consumer, on pipes with a nominal bore of more than 15 mm, made by furnace welding and 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).

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).

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 is allowed on the threads of the thread, 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 batch.

(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 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

Date of introduction 01.01.1977

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
Conditional pass	Outside diameter	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

The maximum deviation in the plus side along the wall thickness is limited by the maximum deviations in the mass of pipes.
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
Conditional pass	Number of threads with conditional passage	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

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.

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.

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).

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 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.

2.13. 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.

3.4. All pipes are subjected to mass control.

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.

4.6. 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)

There are many varieties of shaped products with a round profile. Products made of plastics (including composite ones) have seriously competed with traditional pipes made of metals. But, despite the universality of the use of polymer samples, in the conditions of laying routes outside buildings, when used in a number of pressure systems, there is no alternative to hardware. This article is about the features and characteristics of water and gas pipes (VGP).

Specifications for VGP are determined in years. Anyone who wants to understand the issue more thoroughly, it will be easy to do. But since the terminology and most of the parameters are incomprehensible to the average consumer (and therefore uninteresting), and some are not so significant, we will limit ourselves to only the main characteristics that are of practical importance during the installation and operation of a water supply or gas supply system.

Features of water and gas pipes

The material is high quality steel. Pipes can be without a protective coating or. The latter are used for the installation of structures (contours), the operation of which will take place in conditions of excessive humidity. All blanks are welded, which increases their strength.

The main advantages of water and gas pipes:

Mechanical strength.
Long service life.

It is allowed to have:

Small dents that do not reduce Dy or wall thickness.
Risk.
Spot cleaning marks.
Dross.

Signs of marriage

Blisters on the tube.
Cracks.
Chips, scuffs on the end parts.
Delamination of the coating on the "galvanization".

Characteristics of the VGP

The main linear parameters are in "mm".

Length (m): 4 - 12.

By agreement with the customer, in a batch of water and gas pipes, it is allowed to have off-gauge products not exceeding 5% of the total quantity (with a length of 1.5 - 4 m).

Dy: 6 - 150.

Dn: 10.2 - 165.

Wall thickness (limit): for light pipes (L) 1.8 - 4; ordinary (O) 2 - 4.5; reinforced (U) 2.5 - 5.5.

Maximum hydraulic pressure (MPa): categories L and O - 25, reinforced pipes - 32.

At the request of the customer - up to 50.

Weight 1 l.m. (kg): 0.37 - 15.88 (pipes L); 0.4 - 17.81 (O); 0.47 - 21.43 (U).

The mass of galvanized pipes is 3% higher than the value of a similar parameter for samples without a protective coating.

Deciphering the marking of VGP

Positions

Type of pipe: M - with a coupling, R - with a thread, C - with a zinc coating, P - increased accuracy, D - long thread, N - knurled.
Wall thickness.
Length (only measured).
GOST number.

Example 32 x 4 GOST 3262-75 - non-galvanized, random length, normal accuracy, Dy \u003d 32, wall \u003d 4. Ts-R-32 x 4 GOST-6000 3262-75 - the same product with thread, galvanized, measured length 6 m.

The use of water and gas pipes

Primary:

In systems (circuits) of heating, hot water supply, cold water supply, gas supply.
For pumping liquid and gaseous media in production.

Secondary:

Given the high cost of production, zealous owners often give VGP blanks a “second life”.

Structural reinforcement elements.
Sheds.
Fencing.
Jumpers and the like.

Price of steel pipes VGP

It depends on many factors, so it is appropriate to give only a few examples of the cost (in RUB/rm).

15 x 2.8 - within 56 (galvanization - 94).
"Twenty" with the same wall - 74 (coated - 113).
57 x 3 - 187 (308).
76 x 3.5 - 212 (388).

The water and gas pipe will be made of steel for a long time. Alternative options - metal-plastic conduits, ceramic, can only be used in certain areas: local water pipes, free-flow sewage, communication inside the building. However, when installed above ground, the pipeline is exposed to too much weather. This excludes the use of plastic or other products.

Characteristics of the VGP

Water and gas pipes are made from steel blanks - strips, by molding. The edges of the workpiece are welded. The seam is reinforced. Examination of the seam is the first task of quality control, as it represents a high-risk site. According to GOST 3262-75, radiography is used to determine the quality.

Water and gas pipes, as a rule, are made straight-seam, since for these products a more important quality is resistance to internal pressure, rather than resistance to external loads. Pictured is a gas pipeline.

Advantages:

high strength, which allows the use of products for any installation method and in any areas;
oxygen and gas impermeability - these are precisely the properties due to which gas pipelines are built and will be built only from steel products;
low coefficient of expansion - changes in temperature and moisture do not affect the material. The pipeline does not expand, which allows the use of a rigid mount and does not require compensatory devices;
durability - with proper maintenance is 50 years;
affordable cost.

Flaws:

rather large weight, which makes installation difficult and requires a large number of fasteners;
the need for preventive maintenance - the metal accumulates electricity;
the need for thermal insulation when laying in the ground - the freezing liquid expands, while the parameters of the conduit remain unchanged. This leads to damage and breakage.

VGP parameters

Dimensions and possible deviations are regulated by GOST 3262-75.

Outer diameter - from 33 to 165 mm.
Wall thickness - from 1 to 5.5 mm.
Length - unmeasured ranges from 4 to 12 m, measured 4–8 or 8–12 m.

Since we are talking about water pipes, instead of the inner diameter, an indicator such as a conditional passage is used. It is given in both inches and mm.

Product varieties

Different ways of laying the pipeline and different operating conditions imply different technical characteristics from each other. Rental produces several modifications.

Material classification

The raw material in the manufacture of water and gas pipes is carbon steel of various grades. At the same time, GOST 3262-75 regulates two types of products:

conduits made of steel of ordinary accuracy - only the mechanical qualities of the product are controlled. The chemical composition of steel is not investigated. Products are applied to household communication systems;
high-precision steel pipeline - galvanized steel is used in the manufacture, mechanical properties are normalized by GOST 3262-75. Products are used in the construction of large highways, where high pressure resistance is important.

In fact, both types of water and gas pipes are made of steel, but they pass different levels of control. As a result, they get:

black - without galvanizing, more often used when laying gas pipelines;
galvanized - finished products are galvanized - immersed in a zinc melt. A protective layer is formed on the inner and outer surface of the product, which protects against corrosion. Large water mains are constructed from galvanized VGP.

Release form

Pipe water and gas GOST 3262-75 is available:

with threaded ends (knurling or threading) - it is worth noting that the protective layer is damaged during welding, and therefore galvanized products are mounted only by the threaded method;
without thread - welded connection is assumed.

Water pressure resistance

The wall thickness of the water and gas pipeline determines the strength and resistance to a certain hydraulic pressure. The classification is:

light - the working pressure of the liquid should not exceed 25 kg / kV. cm;
ordinary - assumes the same pressure, but allows water hammer;
reinforced - pressure can reach a value of 32 kg / kV. cm.

GOST 7502-98

GOST 8026-92

GOST 8694-75

GOST 8695-75

GOST 8944-75

GOST 8954-75

GOST 8965-75

GOST 8966-75

GOST 10006-80

GOST 10692-80

GOST 11358-89

GOST 18242-72

GOST 18360-93

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

7. EDITION (May 2007) with Amendments Nos. 1, 2, 3, 4, 5, 6 approved in November 1977, December 1978, January 1987, May 1988, November 1989 , November 1991 (IUS 1-78, 2-79, 4-87, 8-88, 2-90, 2-92)

This standard applies to non-galvanized and galvanized steel welded pipes with 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. N 2, 3, 5).

1. ASSORTMENT

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

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. N 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

Dimensions, mm


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

table 2

Dimensions, mm


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 is calculated with a steel density of 7.85 g/cm. 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 size	Limit deviation for precision pipes
	ordinary	elevated
Outer diameter with nominal bore:
up to 40 mm incl.	0.4 mm -0,5
over 40 mm
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 separate pipe.

(Changed edition, Rev. N 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 be as specified in Table 4.

Table 4


Conditional passage, mm	Number of threads with conditional passage	Thread length to the run, mm
		long	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:

Pipe 20x2.8 GOST 3262-75

The same with the clutch:

Pipe M-20x2.8 GOST 3262-75

The same, measured length, threaded:

Pipe P-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.

(Changed edition, Rev. N 1).

2. TECHNICAL REQUIREMENTS

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.

2.1, 2.2. (Changed edition, Rev. N 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.

(Changed edition, Rev. N 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. N 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 furnace welding and 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. N 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. N 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. N 3, 4).

2.8. Pipes must withstand hydraulic pressure:

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

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

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

2.9. Pipes with a nominal bore up to 40 mm inclusive must withstand 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 flattened surfaces equal to 2/3 of the outer diameter of the pipes.

2.8, 2.9. (Changed edition, Rev. N 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. N 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. N 2, 3, 5).

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

2.15. (Deleted, Rev. N 3).

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

(Changed edition, Rev. N 5).

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, 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. N 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. N 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 are selected no more than 1%, but not less than two pipes from the batch, and for pipes manufactured by continuous furnace welding, two pipes per batch.

(Changed edition, Rev. N 3, 4).

3.4. All pipes are subjected to mass control.

(Changed edition, Rev. N 3).

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.

(Changed edition, Rev. N 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 according to GOST 10006. Instead of tensile testing, it is allowed to control mechanical properties by non-destructive methods.

(Changed edition, Rev. N 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.

(Changed edition, Rev. N 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. N 3, 4).

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

(Changed edition, Rev. N 3).

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

(Introduced additionally, Rev. N 3).

4.6. The thread is checked with threaded ring gauges according to GOST 5378 from both ends of the pipe.

The length of the pipes is measured with a tape measure according to GOST 7502. The thread is controlled by gauges according to 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. N 3, 4, 5, 6).

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

(Introduced additionally, Rev. N 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 grease in accordance with regulatory documents.

Section 5. (Changed edition, Rev. N 3).

Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2007