Straight-seam steel pipe GOST 10704 91. Straight-seam electric-welded steel pipes. Another manufacturer and the cost of his products

When manufacturing straight-seam pipes, pay attention to GOST 10704-91, which determines the assortment, and GOST 10705-80, as well as GOST 10706-76, the basic technical requirements for general-purpose pipes. Two welding technologies are determined by the presence of two GOSTs, namely electric arc welding and contact welding with high frequency currents.

In GOST 20295-85, various welding technologies are only mentioned, but are not directly discussed anywhere. It involves resistance welding with high-frequency currents GOST 10705-80, and applies to pipes with a diameter of 10-530 mm.

Large-diameter pipes from 428 to 1420 mm, manufactured by arc welding, are subject to GOST 10706-76. Electric arc welding is carried out with external reinforcement, which means that the pipe is welded in three passes: first, an intermediate seam, then an outer seam, and an inner seam is made for reinforcement. These two GOST standards for longitudinally welded pipes are very similar, but have significant differences.

Based on GOST 10706, small-diameter pipes can be welded with a transverse seam, and those with a diameter of 820 mm or more must have two longitudinal and one transverse seams. It also, unlike GOST 10705, regulates the chamfer at the ends of the pipe. There are also certain differences regarding the grades of steel allowed in the manufacture of pipes. According to GOST 10706-76, two main grades are allowed, these are ST.3 and ST.2, but GOST 10705-80 is no longer limited to two grades; used pipes are widely represented on the secondary market from higher quality steel grades 10 and 20. The production of pipes from steel grade 17GS and its analogues according to GOST 10705-80 and 10706-76 is not provided.

The visual characteristics of a seam from high-frequency welding are much higher than from electric arc welding; such a seam is narrower and almost invisible. Irregularities in the form of a non-smooth thickening in the seam zone are formed on the inner surface of the pipe, called burr. In some cases, the burr is flattened or ground, and the outer one is removed. After electric arc welding, the seam is wider. It is characterized by the presence of a reinforcement roller with a height of up to 5 mm, on both sides - internal and external.

1. GOST 10704-91: Straight-seam electric-welded steel pipes developed and introduced by the USSR Ministry of Metallurgy
DEVELOPERS V. P. Sokurenko, Ph.D. tech. sciences; V. M. Vorona, Ph.D. tech. sciences; P. N. Ivshin, Ph.D. tech. sciences; N. F. Kuzenko, V. F. Ganzina
2. APPROVED AND ENTERED INTO EFFECT by Resolution of the Committee of Standardization and Metrology of the USSR dated November 15, 1991 N 1743
3. INSTEAD GOST 10704-76
4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

5. REPUBLICATION. December 1996

Assortment

Electrically welded steel line-weld tubes. Range

1. This standard establishes the range of steel electric-welded straight-seam pipes.

2. The dimensions of the pipes must correspond to the table. 1.

3. The following are made according to the length of the pipe:

unmeasured length:

• with a diameter of up to 30 mm - at least 2 m;
• with a diameter of St. 30 to 70 mm - at least 3 m;
• with a diameter of St. 70 to 152 mm - at least 4 m;
• with a diameter of St. 152 mm - not less than 5 m.

At the request of the consumer, pipes of groups A and B according to GOST 10705 with a diameter of over 152 mm are manufactured with a length of at least 10 m; pipes of all groups with a diameter of up to 70 mm - a length of at least 4 m;

measured length:

• with a diameter of up to 70 mm - from 5 to 9 m;
• with a diameter of St. 70 to 219 mm - from 6 to 9 m;
• with a diameter of St. 219 to 426 mm - from 10 to 12 m.

Pipes with a diameter over 426 mm are manufactured only in unmeasured lengths. By agreement between the manufacturer and the consumer, pipes with a diameter of over 70 to 219 mm can be manufactured from 6 to 12 m;

a multiple length of at least 250 mm and not exceeding the lower limit established for measuring pipes. The allowance for each cut is set to 5 mm (unless another allowance is specified) and is included in each multiplicity.

Table 1

Continuation of the table. 1

Continuation of the table. 1

Continuation of the table. 1

Continuation of the table. 1

Continuation of the table. 1

Continuation of the table. 1

Notes:
1. When manufacturing pipes in accordance with GOST 10706, the theoretical weight increases by 1% due to the strengthening of the seam.
2. By agreement between the manufacturer and the consumer, pipes with dimensions of 41.5x1.5-3.0 are manufactured; 43x1.0; 1.5-3.0; 43.5x1.5-3.0; 52x2.5; 69.6x1.8; 111.8x2.3; 146.1x5.3; 6.5; 7.0; 7.7; 8.5; 9.5; 10.7; 152.4x1.9; 2.65; 168x2.65; 177.3x1.9; 198x2.8; 203x2.65; 299x4.0; 530x7.5; 720x7.5; 820x8.5; 1020x9.5; 15.5; 1220x13.5; 14.6; 15.2 mm, as well as with intermediate wall thickness and diameters within the limits of the table. 1.
3. Pipe sizes enclosed in brackets are not recommended for new design.
3.1. Pipes of measured and multiple lengths are manufactured in two length accuracy classes:
I - with cutting ends and deburring;
II - without facing and deburring (with cutting in the mill line).
3.2. Maximum deviations along the length of measuring pipes are given in table. 2.

table 2

3.3. Maximum deviations along the total length of multiple pipes should not exceed:
+ 15 mm - for pipes of class I accuracy;
+ 100 mm - for pipes of class II accuracy.
3.4. At the consumer's request, pipes of measured and multiple lengths of class II accuracy must have ends with flanged ends on one or both sides.
4. Maximum deviations for the outer diameter of the pipe are given in table. 3.

Table 3

Note. For diameters controlled by perimeter measurements, the largest and smallest perimeter limits are rounded to the nearest 1 mm.
5. At the request of the consumer, pipes in accordance with GOST 10705 are manufactured with a one-sided or offset tolerance on the outer diameter. One-sided or shifted tolerance should not exceed the sum of the maximum deviations given in table. 3.
6. Maximum deviations in wall thickness must correspond to:
± 10% - for pipe diameters up to 152 mm;
GOST 19903 - for pipe diameters over 152 mm for the maximum sheet width of normal accuracy.
By agreement between the consumer and the manufacturer, it is allowed to manufacture pipes with a one-sided tolerance for wall thickness, while the one-sided tolerance should not exceed the sum of the maximum deviations for wall thickness.
7. For pipes with a diameter of over 76 mm, a thickening of the wall at the burr by 0.15 mm is allowed.
8. Pipes for pipelines with a diameter of 478 mm and more, manufactured in accordance with GOST 10706, are supplied with maximum deviations for the outer diameter of the ends given in table. 4.

Table 4

9. The out-of-roundness and uniformity of pipes with a diameter of up to 530 mm inclusive, manufactured in accordance with GOST 10705, must be no more than the maximum deviations for the outer diameter and wall thickness, respectively.
Pipes with a diameter of 478 mm or more, manufactured in accordance with GOST 10706, must be of three accuracy classes for ovality. The ovality of the pipe ends should not exceed:
1% of the outer diameter of pipes for 1st accuracy class;
1.5% of the outer diameter of pipes for 2nd accuracy class;
2% of the outer diameter of pipes for 3rd accuracy class.
The ovality of the ends of pipes with a wall thickness of less than 0.01 outer diameter is established by agreement between the manufacturer and the consumer.
10. The curvature of pipes manufactured according to GOST 10705 should not exceed 1.5 mm per 1 m of length. At the request of the consumer, the curvature of pipes with a diameter of up to 152 mm should be no more than 1 mm per 1 m of length.
The total curvature of pipes manufactured in accordance with GOST 10706 should not exceed 0.2% of the pipe length. The curvature per 1 m length of such pipes is not determined.11. Technical requirements must comply with GOST 10705 and GOST 10706.

Examples of symbols:
Pipe with an outer diameter of 76 mm, a wall thickness of 3 mm, measured length, class II accuracy in length, made of steel grade StZsp, manufactured according to group B of GOST 10705-80:

Pipe 76 x 3 x 5000 IIGOST 10704-91
V - St3spGOST 10705-80

The same, with increased accuracy in outer diameter, length multiple of 2000 mm, class I accuracy in length, from grade 20 steel, manufactured according to group B of GOST 10705-80:

Pipe 76n x 3 x 2000cr. IGOST 10704-91
B - 20GOST 10705 - 80

Pipe with an outer diameter of 25 mm, a wall thickness of 2 mm, a length multiple of 2000 mm, class II length accuracy, manufactured according to group D GOST 10705-80;

Pipe 25 x 2 x 2000 cr. IIGOST 10704-91
DGOST 10705 - 80

Pipe with an outer diameter of 1020 mm, increased manufacturing accuracy, wall thickness 12 mm, increased accuracy in the outer diameter of the ends, 2nd class accuracy in ovality, unmeasured length, made of steel grade StZsp, manufactured according to group B GOST 10706 -76

Pipe 1020 n x 12 - Fri - 02 kpGOST 10704 - 91
V - St3spGOST 10706 - 76

Note. In the symbols of pipes that have undergone heat treatment throughout the entire volume, the letter T is added after the words “pipe”; pipes that have undergone local heat treatment of the weld, the letter L is added.

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Metallurgy

DEVELOPERS

V.P. Sokurenko, Ph.D. tech. sciences; V.M.Vorona, Ph.D. tech. sciences; P.N.Ivshin, Ph.D. tech. sciences; N.F. Kuzenko, V.F. Ganzina

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the Committee of Standardization and Metrology of the USSR dated November 15, 1991 N 1743

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

5. REPUBLICATION. February 2007

AMENDED Change No. 1, adopted by the Interstate Council for Standardization, Metrology and Certification by correspondence (protocol dated May 12, 2011 No. 39). Developer state Ukraine. By order of Rosstandart dated December 22, 2011 N 1576-st, it came into force on the territory of the Russian Federation from October 1, 2012

Change No. 1 was made by the database manufacturer according to the text of IMS No. 3, 2012

1. This standard establishes the range of steel electric-welded straight-seam pipes.

2. The dimensions of the pipes must correspond to table 1.

3. The following are made according to the length of the pipe:

Unmeasured length: with a diameter of up to 30 mm - at least 2 m; with a diameter of St. 30 to 70 mm - at least 3 m; with a diameter of St. 70 to 152 mm - at least 4 m; with a diameter of St. 152 mm - not less than 5 m.

At the request of the consumer, pipes of groups A and B according to GOST 10705 with a diameter of over 152 mm are manufactured with a length of at least 10 m; pipes of all groups with a diameter of up to 70 mm - a length of at least 4 m;

Measured length: with a diameter of up to 70 mm - from 5 to 9 m; with a diameter of St. 70 to 219 mm - from 6 to 9 m; with a diameter of St. 219 to 630 mm - from 10 to 12 m.

Pipes with a diameter over 630 mm are manufactured in unmeasured lengths. By agreement between the manufacturer and the consumer, pipes of measured length can be manufactured up to 12 m - with a diameter of St. 70 to 219 mm, up to 18 m - with a diameter over 219 to 630 mm;

A multiple length of at least 250 mm and not exceeding the lower limit established for measuring pipes. The allowance for each cut is set to 5 mm (unless another allowance is specified) and is included in each multiplicity.

3.1. Pipes of measured and multiple lengths are manufactured in two length accuracy classes:

I - with cutting ends and deburring; II - without facing and deburring (with cutting in the mill line).

3.2. Maximum deviations along the length of measuring pipes are given in Table 2.

3.3. Maximum deviations along the total length of multiple pipes should not exceed:

15 mm - for pipes of class I accuracy; +100 mm - for pipes of class II accuracy.

3.4. At the consumer's request, pipes of measured and multiple lengths of class II accuracy must have ends with flanged ends on one or both sides.

4. Maximum deviations for the outer diameter of the pipe are given in Table 3.

5. At the request of the consumer, pipes in accordance with GOST 10705 are manufactured with a one-sided or offset tolerance on the outer diameter. One-sided or shifted tolerance should not exceed the sum of the maximum deviations given in Table 3.

6. Maximum deviations in wall thickness must correspond to:

±10% - for pipe diameters up to 152 mm; GOST 19903 - for pipe diameters over 152 mm for the maximum sheet width of normal accuracy.

By agreement between the consumer and the manufacturer, it is allowed to manufacture pipes with a one-sided tolerance for wall thickness, while the one-sided tolerance should not exceed the sum of the maximum deviations for wall thickness.

7. For pipes with a diameter of over 76 mm, a thickening of the wall at the burr by 0.15 mm is allowed.

8. Pipes for pipelines with a diameter of 478 mm and more, manufactured in accordance with GOST 10706, are supplied with maximum deviations for the outer diameter of the ends given in Table 4.

9. Ovality and equi-walling of pipes with a diameter of up to 630 mm inclusive, manufactured in accordance with GOST 10705, must be no more than the maximum deviations for the outer diameter and wall thickness, respectively.

Pipes with a diameter of 478 mm or more, manufactured in accordance with GOST 10706, must be of three accuracy classes for ovality. The ovality of the pipe ends should not exceed:

1% of the outer diameter of pipes for 1st accuracy class; 1.5% of the outer diameter of pipes for 2nd accuracy class; 2% of the outer diameter of pipes for 3rd accuracy class.

The ovality of the ends of pipes with a wall thickness of less than 0.01 outer diameter is established by agreement between the manufacturer and the consumer.

(Changed edition, Amendment No. 1).

10. The curvature of pipes manufactured according to GOST 10705 should not exceed 1.5 mm per 1 m of length. At the request of the consumer, the curvature of pipes with a diameter of up to 152 mm should be no more than 1 mm per 1 m of length.

General curvature of pipes manufactured according to GOST 10706

The same, increased accuracy in outer diameter, length multiple of 2000 mm, I class of accuracy in length, from grade 20 steel, manufactured according to group B of GOST 10705-80:

Pipe with an outer diameter of 25 mm, a wall thickness of 2 mm, a length multiple of 2000 mm, class II length accuracy, manufactured according to group D GOST 10705-80:

Pipe with an outer diameter of 1020 mm, increased manufacturing accuracy, wall thickness 12 mm, increased accuracy in the outer diameter of the ends, 2nd class of accuracy in ovality, unmeasured length, made of steel grade StZsp, manufactured according to group B of GOST 10706-76:

Note. In the symbols of pipes that have undergone heat treatment throughout the entire volume, the letter T is added after the words “pipe”; For pipes that have undergone local heat treatment of the weld, the letter L is added.

The electronic text of the document was prepared by Kodeks JSC and verified according to: official publication M.: Standartinform, 2007

Straight-seam welded pipes (GOST 10704–91 and 10705–80) can be produced in several different groups with or without additional heat treatment.

1 Electric-welded straight-seam steel pipes – GOST 10705–80

This State Standard provides information on the range and manufacturing technology of straight-seam welded pipe products that have a diameter from 10 to 530 millimeters. They are produced from low-alloy materials and for use as part of a variety of building and other structures, as elements of pipelines and products with different purposes.

Note that GOST 10705–80 “does not comply” with pipes used for the production of electric thermal heaters. By quality characteristics straight-seam steel pipe (GOST 10704–91 and 10705–80) is assigned to one of four groups. Products of group "A" are produced according to Gosstandart 380 from semi-quiet, calm and boiling steel 1, 2, 3 and 4. Finished products are produced with standardized mechanical parameters. Products of group "B" are manufactured:

• according to State Standard 9045 from steel 08Yu;
• according to standard 380 from St1–St4;
• according to standard 19281 from steels with a low level of alloying, in which carbon should not be more than 0.46 percent (this is how pipes with a cross-section of more than 114 mm are made);
• according to Gosstandart 1050 from St10, 08, 20 and 15 (sp, kp, ps).

Also, products of group “B” (all of them are necessarily standardized according to their chemical composition) are made from steel 22ГУ, which has the following chemical composition (in percentage):

• from 1.2 to 1.4 – manganese;
• from 0.15 to 0.22 – carbon;
• 0.03 – titanium;
• from 0.15 to 0.3 – silicon;
• from 0.02 to 0.05 – aluminum;
• up to 0.02 – phosphorus and calcium;
• up to 0.4 – chromium;
• up to 0.01 – sulfur;
• up to 0.012 – nitrogen.

Pipes of group "B" are already standardized both in terms of chemical composition and mechanical characteristics. Moreover, they are produced from steels that are used for the manufacture of products of group "B". In addition, straight-seam pipe structures can also be of group “D”. In this case, they are standardized according to hydraulic test pressure.

GOST says that:

• pipes made from steels with a small amount of alloying elements can be produced either without additional heat treatment or with it (for example, with), and the treatment is carried out over the entire welded joint or throughout the volume of the structure);
• products made from carbon steels are also processed at elevated temperatures, but they can also be reduced in hot technology, but products made from St1 never undergo heat treatment;
• a plant that produces electric-welded structures has the right to independently choose a specific heat treatment option; it is allowed to carry it out even in a protective environment, but under a preliminary agreement with the buyer of the finished product.

2 Special requirements for welded pipes with a straight seam in accordance with GOST 10705

Finished tubular products are subject to the following Gosstandart requirements:

• Their surfaces should be free of dulls, cracks, flaws and captivity. If pipes are processed at high temperatures, the presence of an oxide film on the products is allowed. In this case, the presence of scale is not allowed.
• In cases where traces of stripping, small scratches, nicks, scale, ripples, and dents do not bring the cross-section of the pipe structure and the thickness of its wall beyond the permissible deviations, they may be present on the products.
• The welding area must be cleaned, and seams that lack fusion are also welded.
• The edges can be offset relative to the wall thickness (nominal) by no more than 10 percent. For pipes with a cross-section of 159 mm or more, the permissible displacement increases to 20 percent.

The mechanical parameters of base steel for hot-reduced and heat-treated products vary depending on its grade:

• relative elongation: from 20 (steel 26KhMA, 17G1S, 09G2S, 20F, 13KhFA) to 30 (08Yu) percent;
• yield strength: from 174 (08Yu and 08kp) to 343 (26KhMA, 17G1S, etc.) N/mm 2;
• tensile strength (temporary): from 255 to 490 kgf/mm 2.

The mechanical characteristics of low-alloy alloys and steel 22ГУ may differ from the standard ones as agreed with consumers.

Other important provisions of the document describing the production process of longitudinally welded pipes include the following requirements:

• one seam in the transverse direction is allowed on products with a cross-section of 57 mm or more;
• if heat-treated pipes are repaired by welding, they must be re-processed along the seam or in volume using a similar method;
• The external burr on the products must be removed;
• Burrs are removed from the ends of the structures (by stripping), and the pipes are cut at right angles.

3 Longitudinal welded pipes – GOST 10704–91

This official document establishes the dimensions of pipe products made from steels in accordance with GOST 10705, as well as their maximum deviations from standard values ​​and the range of electric-welded pipes. From it you can find out that the finished product is manufactured with the following parameters:

• diameter (outer): 10–1420 mm;
• length: unmeasured – 2–5 m depending on the cross-section of the pipe, measured – 5–12 m; multiple (the multiple should not be higher than the lower limit of the measured length and have a multiple of 25 cm or more);
• wall thickness: 1–32 mm;
• mass (theoretical) of one kilogram of finished product: varies from 0.222 kg for a pipe with a wall of 1 mm and a cross-section of 10 mm to 779 kg for products with a wall of 32 mm and a cross-section of 1020 mm.

It is important to know that when products are manufactured according to State Standard 10706, the weight of the pipes is large for all products, which is due to the need to strengthen the weld.

The length (measured) deviations of pipe structures can be as follows:

• +5 cm for products of the 2nd class and +1 cm of the 1st class (pipes less than 6 meters long);
• +7 and +1.5 cm for pipes longer than 6 meters.

In terms of multiple length, the deviations that the standard allows are +10 cm for products of the 2nd class and +1.5 cm for the 1st, regardless of the length of the structure. 1st class pipes are understood as products with deburrs and cut ends, 2nd class – without deburring and trimming.

The manufacturing accuracy of straight-seam welded pipes according to GOST 10704–91 is:

• increased;
• ordinary.

Production accuracy is taken into account when describing the permissible deviations of finished products from their diameter (outer):

• pipes over 1020 mm: ±6.0 mm (increased accuracy) and ±0.6% (normal);
• 426–1020: ±0.65% and ±0.7%;
• 193.7–426: ±0.65% and ±0.75%;
• 51–193.7: ±0.7% and ±0.8%;
• 30–51: ±0.35 mm and ±0.4 mm;
• 10–30: ±0.25 mm and ±0.3 mm.

Pipes with a cross section of less than 10 mm of normal accuracy may have deviations of up to ±0.2 mm; for high-precision products, deviations are not provided.

The difference in thickness and ovality value of electric-welded products with a cross-section of no more than 530 mm is possible no higher than the permitted deviations in wall thickness and outer section, respectively. But the curvature of the pipes cannot be higher than 1.5 mm per meter of their length. For products that are planned to be used in critical structures as components, the curvature must be even less - up to 1 mm.

Electric welded pipes Andwater and gas pipes - welded pipes that have a similar production method and appearance, but differ in some parameters. AND steel water and gas pipes GOST(steel pipe VGP) , electric-welded (ES pipes) pipes are made from strip, sheet metal, the blank is formed on special mills, and then welded, forming a seam, which gives the rolled product high strength and wear resistance. GOST electric-welded steel pipes are straight-seam, a straight seam is formed when welding along the longitudinal axis. This seam is performed first from the outside, then from the inside. U GOST water and gas pipelines The pipe seam is even more reinforced. Also, VGP pipes can undergo reduction - the billet is drawn out in mills to reduce their cross-section, the wall thickness may change, or may remain the same. Straight-seam pipes are most in demand on the market.

Long-seam pipes electric welded ones can be additionally thermally treated along the entire seam or throughout the entire pipe and be hot-reduced. ES pipes, which have few alloying elements in their composition, can be subjected to recrystallization annealing. Rolled products made from St1 grade are not exposed to thermal effects. Heat treatment in a protective environment is pre-agreed with the buyer at the plant. Plants have the right to choose a certain type of heat treatment for electric-welded pipes themselves.

It is believed that because of the seam, welded pipes are not very reliable in use, however, the production of pipes on high-precision equipment and high-quality welding of the seam, strength testing, seam control (radiography) and the issuance of quality certificates for these products guarantee the production of a durable, reliable material that will last more than one year. Only some kind of rough external influence can damage the integrity of this rolled product; in particular, bending pipes leads to damage to the seam. For pipelines, round steel pipes are used, since plastic and metal-plastic pipes cannot withstand the required gas or water pressure.

Both pipes can be additionally galvanized, which makes them suitable for use in domestic water supply systems. Such pipes serve for a long time, rust does not appear inside the pipe, various waste does not stick to them, but the weight of the pipe increases. Galvanized pipe may be a quarter heavier than non-galvanized. The anti-corrosion properties of rolled pipes are also affected by the grade of steel from which the pipe is made. In addition, galvanized pipes are resistant to high temperatures, so they are used for heating networks in which water temperatures are above 140 degrees C. To prevent underground pipelines from rusting, a bitumen coating is used, it increases the service life of the pipes. Professionals connect galvanized pipes with care, as the coating can be damaged; they use threading or welding to connect pipes. Galvanizing of pipes occurs by immersion in molten zinc or the use of toxic zinc salts.

The difference between the VGP pipe and the ES pipe:

1. According to GOSTs:

Water-gas and electric-welded pipes have their own quality standards. VGP steel pipes are produced according to GOST 3262-75 (this State Standard regulates the range and technical conditions of pipes), and ES pipes - according to GOST 10704-91 (implies the range straight-seam electric welded pipes ) And

GOST 10705-80 (standardizes manufacturing technologies for electric-welded pipes).

2. Difference between black pipes in size:

VGP and ES pipes differ in wall thickness, outer section, inner diameter, nominal bore. The conditional diameter is the average value of the internal cross-section of the pipe in mm. Water and gas pipes are measured and designated by nominal diameter; steel pipeselectric-welded straight-seam - standardized by outer diameter.

Maximum deviations in pipe weight and wall thickness are prescribed in GOST standards.

Water and gas pipelines pipes GOST 3262 During the Soviet era, they were measured in inches; many still use this designation.

For example, an inch pipe is considered to have a nominal bore of 25 mm ( VGP pipe DN 25), half-inch - 15mm ( VGP pipe DN 15),

three quarters of an inch - VGP pipe Du 20,

inch and a quarter - water and gas pipe with a nominal bore of 32 mm;

1.5 inches - DN 40,

two-inch pipe - with a nominal bore of 50mm ( VGP pipe DN 50).

Table diameters of VGP pipes, assortment of electric-welded straight-seam pipes available on our website in the “Rolled Metal” section. There is also a division of VGP pipes according to wall thickness into: light, ordinary and reinforced.

Thus, water and gas pipe with nominal bore 50 mm ( pipe VGP 50) has an outer diameter of 60 mm, it corresponds to an analogue - electric welded steel pipe GOST 10704 91 60thaya - with an outer diameter of 60 mm.

For VGP pipes DN 15 analog- outer diameter of electric-welded pipes = 21,3

3. By application:

Electric welded pipes GOST 10704 used for external water and gas pipelines with different pressures, oil pipelines, heating networks; in the production of furniture, in the construction of buildings and for the construction of structures: fences, poles, supports, for laying cables. GOST 10705 applies to pipes that are intended for pipelines and various structures. ES pipes are used in the food, chemical, automotive industries, mechanical engineering, nuclear engineering, as well as for the manufacture of shafts, bearings, etc.

Pipes VGP 3262 75 used mainly for internal (drinking) water supply, they are intended for small gas pipelines, supplying communications to rooms, pipe 3262 used for heating systems, manufacturing of metal structures, in mechanical engineering and aircraft manufacturing, in industrial construction, in agriculture; thick pipes are needed for main pipelines; Some pipes are threaded. Water and gas pipes are widely used by housing and communal services.

The required cross-section and diameter of the pipe are selected for the water supply system, taking into account the throughput of the water supply system, the number of pipe joints and the total length of the water supply system, as well as the number of turns of the pipe. For risers, a VGP pipe of DN 25 and 20 is usually used; to supply water to the equipment, a pipe of 15 and 10 mm is used.

4. By steel grades and GOST standards for the steel used.

Steel water and gas pipes GOST 3262 is made from St1 - St3 (ps/sp/kp), steel 10, steel 20, 08ps/kp according to GOST 380 and GOST 1050. These carbon steels do not indicate the chemical composition and mechanical properties.

For the production of ES pipes, the following grades are used: St1-4, 08, 20, 10 according to the same GOST 380 and GOST 1050. ES pipes are made from low-alloy and carbon steels. Electric-welded pipes are divided into quality groups: A, B, C, D, mechanical properties, chemical composition, and pressure tests are determined.

5. By pressure test. All pipes are tested for density and strength using hydraulic pressure. This is one of the types of non-destructive testing.

Pipes VGP GOST 3262 must withstand hydraulic pressure:

• light and ordinary pipes
• 2.4 MPa,
• reinforced - 3.1 MPa.

For ES pipes these indicators are equal:

• for pipes with a diameter of up to 102 mm, the pressure gauge shows 6 MPa,
• more diameter of electric-welded steel pipes - 3Mpa.

Also, various electric welded pipes are subjected to impact bending, flattening, expansion testing, bending, stretching and other strength tests.

Buy electric welded pipe, buy VGP pipe

Electric welded pipe price per ton, water and gas pipe price, water and gas pipe diameters the client can independently find it on the company’s website. VGP pipe price, ES pipe price depend on the manufacturer, steel grade and wall thickness, pipe weight, and the presence of zinc coating. The smaller the pipe wall, the lighter it is, which means the structure is easier to manufacture, and the costs for metal and its delivery by transport are lower.

You can always get the following information from our managers: GOST 10704 straight-seam electric-welded steel pipes price per meter, electric welded steel pipe price for the quantity you need, 102*3.5 electric welded pipe price per meter, steel water and gas pipe price per meter . We are always happy to help the buyer with the delivery of pipes to the site and ordering a small batch from other regions, which will be significantly more profitable for the client than on his own. We also carry out railcar deliveries of rolled metal products.

Electric-welded steel pipes GOST 10704-91 are the most widely used among all pipe products. They are used in a wide variety of sectors of the economy and industry, and not only for laying pipelines for various purposes, but also in the construction industry and for the manufacture of various structures, products and their parts. Therefore, the range and characteristics of these pipes are of interest to a very wide range of consumers of pipe products.

1

Perhaps the first thing anyone who wants to get acquainted with the range and characteristics of products of standard 10704 needs to know is the following. Since its development (judging by the standard number, this is 1991) and its entry into force in 1993, many changes have been made to this GOST, affecting both the range of pipes produced (diameters and wall thicknesses were added) and some of their parameters .

Electric welded pipe GOST 10704 91

Therefore, when searching for GOST 10704 on the Internet or other sources, you should pay attention to the presence of these same changes in the material found. They usually come in the form of an appendix or are already included in the text, about which there should be appropriate comments. Otherwise, you will have to deal with outdated and partly distorted information. This, by the way, applies to all other GOST standards, especially if they are older than 5–10 years.

In this article, all information about pipes of standard 10704 is given in their latest edition. That is, taking into account all the changes made to this GOST over the entire period of its existence and use.

Now about what else it is advisable to know before becoming familiar with standard 10704. This GOST, as many people know, contains the assortment (list of manufactured standard sizes) and the main characteristics: dimensions, weight, permissible deviations from them and similar information. And the technical conditions (requirements) for production (classification according to quality indicators, steel grades, mechanical and other properties, and so on) are not specified. They are given immediately in 2 other standards: 10705-80 and 10706-76.

Moreover, each of them actually sets technical requirements for the production of its own separate type of pipes. But at the same time, the range and dimensions of products produced in accordance with both GOSTs must necessarily comply with the requirements of the standard 10704 in question. And in it, in turn, there are references to documents 10705 and 10706. They are given when the pipe has some characteristics described in GOST 10704 depend on the specific technical conditions it is manufactured according to. This point should also be known and taken into account when familiarizing yourself with standard 10704.

2

The dimensions (range) of pipes produced according to standard 10704 must correspond to the data specified in Table given at the end of the article. 5. It also gives the theoretical weight of 1 meter for each standard size of products. Moreover, this mass is indicated for pipes produced. If manufactured according to standard 10706, the theoretical weight will be 1% more, due to the reinforced seam.

In addition to those given in Table 5, standard 10704 allows the manufacture of pipes of a number of other sizes, which are listed in the note after the table. In the latter, it should be noted, there are sizes enclosed in brackets. Standard 10704 does not recommend their use in any new designs.

In straight-seam pipes, the seam is located along the product along its entire length

According to the length, welded products of this GOST are produced in three main types. Namely: unmeasured, multiple and measured lengths. All these types of pipes have their own specific requirements. Unmeasured products are produced with a diameter (mm) and must be length (m):

• up to 30 mm – length at least 2 m;
• over 30 to 70 – minimum 3 m;
• over 70 to 152 – minimum 4 m;
• over 152 – not less than 5 m.

Unmeasured products of groups A and B with a diameter greater than 152 mm, manufactured according to standard 10705, upon request of the consumer (customer), are produced with a length of at least 10 m. And products of all groups with a size of up to 70 mm, upon request, are made with a length of no shorter than 4 m.

Pipes of different diameters

Measured products are produced with a diameter (mm) and should be length (m):

• if up to 70 mm – then the length is within 5–9 m;
• over 70 to 219 – 6–9 m;
• over 219 to 630 – 10–12 m.

Tubular products with a diameter of more than 630 mm are produced unmeasured. By agreement between the manufacturer and the ordering party, it is allowed to produce measured products with a length of up to 12 m - when its diameter is over 70 and inclusive up to 219 mm, and also up to 18 m - if more than 219 mm up to 630 mm.

Multiple-length pipes are produced with a multiplicity of at least 250 mm, which must not exceed the lower limit (total length) regulated for measured products. Each cut is made with an allowance of 5 mm (unless otherwise specified). The allowance is included (taken into account) in each multiple.

Straight-seam pipes for gas supply

Welded pipe products are divided into 2 classes based on the manufacturer’s accuracy of maintaining their length. Moreover, this division applies only to products of multiple and measured lengths. The designation and characteristics of these classes are as follows:

• I – the ends of the pipe are trimmed and then deburred;
• II – trimming and subsequent deburring are not performed (cutting of the product is done in the mill line).

3 Permissible deviations from dimensions and lengths and other requirements

In terms of total length, the maximum deviations of multiple products of class I accuracy should not exceed +15 mm, and class II. – +100 mm. Maximum deviations in the length of measured pipe products are given in Table. 1 (also by class).

Table 1

At the request of the party ordering the pipes, the ends of measured and multiple products of class II accuracy are trimmed by the manufacturer on one or both sides.

According to the outer diameter, the maximum deviations of pipes are given in Table. 2 (in terms of manufacturing accuracy of products).

table 2

Note. If the diameter of the pipe is controlled by measuring its perimeter, then the limit values ​​of the latter (smallest and largest) should be rounded to the nearest 1 mm.

According to standard 10704, at the request of the consumer, products manufactured in accordance with GOST 10705 are allowed to be produced with a biased or one-sided tolerance on the outer diameter. But such a deviation should not be greater than the sum of the tolerances Table. 2.

Electric welded steel pipes

Tolerances for the wall thickness of pipe metal products must meet the following requirements:

• for products with an outer diameter of 152 mm and less – ±10%;
• when the diameter of pipe products is more than 152 to 1020 mm, and when for its production, rolled sheets of maximum width were used, produced with normal accuracy - in accordance with GOST 19903;
• over 1020 – according to Table. 3 below.

Table 3

Standard 10704 allows, upon agreement on this issue between the customer and the manufacturer, the production of pipe products with a one-sided tolerance on the size of the wall thickness. But such a deviation should not be greater than the sum of the tolerances given above. For products with a diameter exceeding 76 mm, it is permissible to thicken the wall directly at the burr in excess of the permissible maximum deviations, but only by 0.15 mm.

Pipes manufactured according to standard

Products for pipelines with a diameter of 478 mm and larger, manufactured according to standard 10706, are subject to additional requirements for the diameter of the ends. The outer diameter of the latter should not differ from the nominal size of the pipe by an amount greater than those indicated in Table. 4 maximum deviations.

Table 4

Also, standard 10704 contains requirements for equal thickness and ovality of welded pipe products manufactured according to it. For products manufactured in accordance with GOST 10705, with an outer diameter of up to 630 mm inclusive, they must be within (not more than) the tolerances for the outer size and wall thickness, respectively.

Products with a diameter starting from 478 mm and larger, manufactured according to standard 10706, must necessarily have 3 accuracy classes in terms of ovality. Thus, the ovality of the ends of these pipe products should not exceed the following values:

• for pipes of 1st accuracy class – 1% of the outer diameter of the product;
• 2 classes – 1.5%;
• 3rd grade – 2%.

The ovality of the ends of products with a wall thickness less than 0.01 of the outer diameter must be established by agreement between the manufacturer and the customer.

The curvature of products manufactured according to standard 10705 should not exceed 1.5 mm in any 1 m of their length. For products of this GOST with a diameter up to and including 152 mm, the customer may require the manufacturer to comply with the curvature for any 1 m of length within a range of no more than 1 mm.

For products manufactured according to standard 10706, only the overall curvature is regulated - for the entire length of the pipe. It is limited to 0.2% of the length of the product. The curvature for 1 m of these pipes is not regulated.

Table 5

Continuation of the table. 5

Continuation of the table. 5

Continuation of the table. 5

Note:

1. Blank columns in the table mean that the pipe is not produced with these dimensions.
2. By agreement between the customer and the manufacturer, it is possible to manufacture pipes with dimensions: 41.5x1.5–3.0; 43x1.0 and 1.5–3.0; 43.5x1.5–3.0; 52x2.5; 69.6x1.8; 111.8x2.3; 146.1x5.3, 6.5, 7.0, 7.7, 8.5, 9.5 and 10.7; 152.4x1.9 and 2.65; 168x2.65; 177.3x1.9; 198x2.8; 203x2.65; 299x4.0; 530x7.5; 820x8.5; 1020x9.5 and 15.5; 1220x13.5, 14.6 and 15.2 mm, as well as with intermediate diameters and wall thicknesses within their values ​​​​in the table. 5.