The METALLSERVICE company supplies the entire range of steel water and gas pipes that meet the requirements of GOST 3262-75. Wholesale prices apply to all metal products.

The catalog presents galvanized and non-galvanized products with a diameter of 8–100 mm, having a rolled or cut cylindrical thread or without it. Rolled metal of this type is always available in warehouses in Moscow, St. Petersburg, Samara, Rostov-on-Don, Penza, Novosibirsk, Khabarovsk and other cities. Delivery is carried out throughout Russia and the Republic of Belarus. The speed of shipment depends on the batch ordered and averages 1–12 hours.

Classification of gas and water pipes according to GOST 3262-75

There are several length options for products:

• measured (4–12 m);
• multiple of the measured one (up to 12 m, allowance for each undercut - 5 mm, longitudinal deviation along the entire length - up to 10 mm);
• unmeasured (according to custom size, within 4–12 m).

Up to 5% of the total number of unmeasured VGP pipes manufactured in accordance with GOST 3262-75 can be made with a length of 1.5–4 m. Over the entire length of the thread made by rolling, the internal diameter of the products can be reduced by 10%.

The weight of 1 m of the presented metal products is indicated taking into account the density of the steel alloy of 7.85 g per cubic meter. cm. At the same time, galvanized VGP pipes weigh 3% more than non-galvanized ones.

Depending on the degree of compliance with standard geometric parameters, pipes are divided into 2 classes:

Based on wall thickness, products are divided into light, ordinary and reinforced. On products of the last two types, with a nominal bore of more than 10 mm, threads can be applied at both ends. There are products to choose from, both without threads and without couplings, or with both.

The VGP pipe, the abbreviation in the name of which stands for “water and gas pipeline,” is specially designed for laying water and gas communications. Even in our time, when modern manufacturers offer a huge range of pipes made from various materials, such specialized tubular steel products are very popular among construction and repair organizations, enterprises operating in the housing and communal services sector.

You can familiarize yourself with all GOST requirements for steel VGP pipes by downloading this document in pdf format from the link below.

The relevance of using pipes of this category

Highly popular VGP pipes, made from steel alloys, is explained very simply. No matter how exceptional the characteristics of today's popular pipes from polymer materials, their use in many cases is simply not possible. Such cases, in particular, include installation of a pipeline on outdoors, where it will be affected by a lot of negative factors.

The demand for such products is also explained by the fact that, according to generally accepted requirements, pipelines for transporting gas and supplying it to consumers can only be made of steel pipes. That is why VGP pipes are simply an irreplaceable material in any gas industry.

How pipes are made

The main material from which pipes belonging to the VGP category are produced is carbon steel. Process their production consists of the following stages:

• first, steel blanks are prepared - strips, which are long metal strips with the required thickness and width parameters;
• then a pipe is formed from the prepared strip, for which it is used special equipment;
• the joint formed on the resulting product is welded using electric welding.

The qualitative characteristics that pipes of the VGP category manufactured using this technology must meet are stipulated by the provisions of GOST 3262-75.

Taking into account the fact that pipes of this category are used in sufficiently difficult conditions, but to the quality of the created weld Very high requirements are imposed; the place of the formed connection is necessarily checked using radiographic control methods.

The main influence on the service life of pipelines made from water and gas pipe products is their operating conditions, as well as the characteristics of the substance that is transported through them. This is explained by the fact that the transported substances have different chemical reactivity.

What to look for when choosing pipes

For the end user who needs such steel pipes to solve specific tasks, certain performance characteristics of these products, allowing you to select them optimally.

In order to make the right choice of such pipes and use them in accordance with their main purpose, it is important to understand the classification of products. The criteria by which such classification is carried out are stipulated by the provisions of GOST 3262-75.

Important criteria for sorting pipes of the VGP category are the material and method of their manufacture, as well as the method of their processing. So, depending on these parameters, pipes are distinguished:

• made of ferrous metal, the surface of which is not protected in any way;
• pipes whose surface is galvanized.

Tubular products, on the inner and outer surfaces of which a thin layer of zinc is applied, even differ in appearance from ordinary ones, as can be seen by comparing their photos. Such surface treatment of pipe products is necessary in order to reliably protect them from the aggressive influence of the external environment. Pipes coated with a thin layer of zinc thanks to chemical properties This metal perfectly resists corrosion and can be successfully used even in the most difficult conditions for a long period of time.

Important parameters of such pipes, regardless of whether they are galvanized or not, are their geometric dimensions: conditional passage, which is denoted by the abbreviation DU, as well as the thickness of their wall.

All geometric parameters of pipes of the VGP category, including their diameter, must comply with the requirements specified in GOST. All geometric dimensions of pipes produced by modern industry can be selected using the appropriate tables.

From the production line, water and gas pipe products can be produced in two modifications:

• without thread;
• with ready-made threads on both ends, which are applied by rolling or cutting.

Decoding the numbers in the designation allows you to find out the exact diameter of the product. Thus, products for which their DU is designated by the number 50 (VGP pipe DU50) have a diameter equal to two inches. And for pipes of the VGP category, the designation of which includes DU25, the diameter is equal to one inch. Accordingly, the markings of water and gas pipes indicate their diameter in millimeters, and converting it into inches is not difficult.

Classification of pipes according to their accuracy class

Water and gas pipes are divided into two main categories according to their accuracy classes.
The first category includes tubular products of ordinary precision. When producing products of this category, they are not standardized following parameters: chemical composition of the manufacturing material, its mechanical characteristics. Pipes of this category are quite successfully used for arranging gas and water communications for domestic purposes.

The second category includes water and gas pipe products of increased precision. Galvanized pipes also belong to this category. From such pipes, for which both the chemical composition of the manufacturing material and its mechanical characteristics are standardized, parts for industrial pipelines are made with increased requirements for their reliability.

Additional options

For the convenience of those who are going to purchase water and gas pipes and use them for certain purposes, the length of such products is also standardized and can correspond to one of the following categories:

• interval 4–12 meters - measured length;
• length of pipes, a multiple of their measured value;
• unmeasured length, which, nevertheless, must be within the measured value.

Consumers of such products should keep in mind that the price is set not per unit of pipe length, but per unit of its weight. It is also important to take into account that the weight of galvanized pipes is 3% higher than the weight of products made from unprotected steel.

Steels from which high-precision galvanized and non-galvanized pipe products are produced must comply with the requirements of GOST 1050, while the chemical composition and mechanical characteristics of the manufacturing material are not subject to standardization. Welds by which water and gas pipe products are connected after they have been formed must be reinforced type.

The range of water and gas pipe products made of black steel involves their production with several options for wall thickness. Depending on this parameter, such products are:

• light class;
• ordinary category;
• reinforced type.

The wall thickness of such products, which can be selected according to the assortment according to the table, is standardized by the requirements of GOST 3262-75. Based on this normative document and a range of pipe products is formed; it also stipulates a number of other parameters that such products must comply with: nominal diameter, outer diameter, theoretical weight of one linear meter.

Pipes various classes designed for operation under various operating pressures. Thus, pipes corresponding to the light category can be operated at a pressure not exceeding 25 kgf/cm2, and reinforced type products - 32 kgf/cm2.

At the request of the customer of a batch of water and gas pipes, long or short threads can be applied to their ends. Galvanized pipe products can be supplied to customers not only with threads, but also equipped with couplings for their installation.

Electric-welded water and gas pipes

Water and gas pipe products manufactured using welded joints, are successfully used for the installation of pipelines through which both liquid and gaseous media are transported. For the production of such pipes, steel grades that are well connected by welding are used: 10, 20, 3SP, 3PS. Depending on the purpose and operating conditions of the pipeline for the installation of which such products will be used, they may be additionally subjected to heat treatment after manufacture.

The measured length of such products is in the range of 9–11.7 meters, and the unmeasured length, which should be within the measured length, is 4–11 m.

Permissible deviations in the dimensions of water and gas pipes depend on the length and diameter of the product. So, if there is a preliminary agreement with the customer, a batch of pipes in their geometric parameters The following deviations are allowed:

• 5% - for pipes whose length is in the range of 1.5–4 meters;
• for galvanized pipe products, where the threads are applied at the ends using rolling technology, it is allowed to reduce the diameter by 10% over the entire area of ​​​​its location.

There is a generally accepted method for calculating the weight of a pipe, where the density of the steel from which it is made is assumed to be 7.85 g/cm3. As mentioned above, the weight of galvanized pipe products is assumed to be 3% more than the weight of conventional ones.

INTERSTATE STANDARD

STEEL PIPES
WATER AND GAS

TECHNICAL CONDITIONS

Date of introduction 01/01/77

This standard applies to non-galvanized and galvanized steel welded pipes with cut or rolled 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 manufactured according to the dimensions and weight given in table. 1.

At the consumer's request, 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) of 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 unmeasured pipes.

Table 1

Conditional passage	O.D	Pipe wall thickness			Weight of 1 m of pipes, kg
			ordinary	reinforced		ordinary	reinforced

Table 2

Conditional passage	O.D	Wall thickness	Weight of 1 m of pipes, kg
Notes: 1. For threads made by rolling on a pipe, its internal diameter is allowed to be reduced by up to 10% along the entire length of the thread. 2. The mass of 1 m of pipes is calculated at a steel density of 7.85 g/cm 3 . Galvanized pipes are 3% heavier than non-galvanized ones.

1.3. Limit deviations The dimensions of the pipes should not exceed those indicated in the table. 3.

Table 3

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

7.5% - for the party;

10% - for a separate pipe.

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

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

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

1.5 mm - with a nominal bore over 20 mm.

1.6. Pipe threads can be long or short. The thread requirements must correspond to those indicated in the table. 4.

Table 4

Conditional bore, mm		Thread length before run		Conditional bore, mm	Number of threads at nominal size	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 consumer’s request.

Examples of symbols

An ordinary pipe, non-galvanized, of normal manufacturing precision, of unmeasured length, with a nominal bore of 20 mm, a wall thickness of 2.8 mm, without threads and without a coupling:

The same with the coupling:

The same, measured length, with thread:

The same, with zinc coating, of unmeasured length, with thread:

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

For pipes for thread rolling in symbol After the word “pipe” the letter N is indicated.

For pipes with long threads, the letter D is indicated in the symbol after the word “pipe”.

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

(Changed edition, Amendment No. 1).

2. TECHNICAL REQUIREMENTS

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

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

2.1; 2.2.

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

(Changed edition, Amendment No. 3).

2.4. Cracks, spots, swellings and declines are not allowed on the surface of the pipes.

Delamination is not allowed at the ends of the pipes.

Individual dents, rippling, scratches, traces of stripping and other defects caused by the production method are allowed, if they do not take the wall thickness beyond the minimum dimensions, as well as a layer of scale 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 seam if there is a gentle thickening in this place along the inner diameter of no more than 1.0 mm.

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

2.5. At the request of the consumer, on pipes with a nominal bore of 20 mm or more on inner surface pipe seam, the burr must be cut or flattened, and 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, manufactured by furnace welding and hot reduction, a gentle thickening with a height of no more than 0.5 mm is allowed on the inner surface of the pipes in the weld area.

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

2.6. The ends of the pipes must be cut at right angles. The bevel of the end is allowed to be no more than 2°. The remaining burrs 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, manufactured by furnace welding.

(Changed edition, Amendment 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, bubbles and foreign inclusions (hartzinc, oxides, sintered mixture), and peeling of the coating from the base metal are not allowed.

Individual flux stains and traces of pipes being caught by lifting devices, roughness and minor local deposits of zinc are allowed.

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

(Changed edition, Amendment 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 hydraulic pressure of 4.9 MPa (50 kgf/cm2)

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

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

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

for pipes with a nominal bore from 15 to 50 mm - no less than 7%;

for pipes with a nominal bore of 65 or more - no less than 4%.

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

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

2.10. At customer's request mechanical properties pipes for parts of water supply and gas pipeline structures must comply with GOST 1050.

2.11. Pipe threads must be clean, without flaws or 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, Amendment No. 3, 4).

2.12. At the seam, blackness on the threads is allowed if the reduction 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 torn (for cut) or incomplete (for rolled) 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, Amendment No. 2, 3, 5).

2.13. On a thread, it is allowed to reduce the useful length of the thread (without running) up to 15% compared to that indicated in the table. 4, and at the consumer’s request up to 10%.

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

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

2.15. (Deleted, Amendment No. 3).

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

(Changed edition, Amendment No. 5).

3. ACCEPTANCE RULES

3.1. Pipes are accepted in batches. The batch must consist of pipes of the same size, the same grade and be accompanied by one quality document in accordance with GOST 10692 with the addition for pipes intended for the manufacture of parts for water supply 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 workpiece manufacturer.

The batch weight is no more than 60 tons.

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

3.2. Each pipe in the batch is subjected to inspection of the surface, dimensions and curvature.

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

* GOST R 50779.71-99 is in force on the territory of the Russian Federation.

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

(Changed edition, Amendment 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, the remains of burrs, the right angle and the chamfer angle (for pipes with beveled 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 per batch.

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

3.4. All pipes are subject to weight control.

(Changed edition, Amendment No. 3).

3.5. Each pipe is subjected to hydraulic pressure testing. With 100% quality control of the weld using non-destructive methods, hydraulic pressure testing may not be carried out. In this case, the ability of the pipes to withstand the test hydraulic pressure is guaranteed.

(Changed edition, Amendment 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 from the batch are selected.

(Changed edition, Amendment No. 2).

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

The results of repeated tests apply to the entire batch.

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 using non-destructive methods.

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

4.2. The surface of the pipes is inspected visually.

4.3. Hydraulic test carried out according to 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, Amendment No. 3).

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

Testing on a mandrel with a taper angle of 30° is allowed.

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

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

(Changed edition, Amendment No. 3).

4.4v. Weld inspection is carried out using non-destructive methods according to regulatory and technical documentation.

(Introducedadditionally, 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 according to GOST 9.301 and GOST 9.302, as well as with devices of the MT-41NTs, MTZON or Impulse type according to the normative and technical documentation.

4.6. The thread is checked using thread ring gauges in accordance with GOST 2533 (third accuracy class).

In this case, the screw-in of the no-go ring gauge onto the thread should be no more than three turns.

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

4.7. The curvature of the pipes is controlled using a straight edge in accordance with GOST 8026 and a set of probes in accordance with NTD.

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

4.8. The right angle of the pipe ends is controlled with a 90° square measuring 160´100 mm class 3 GOST 3749, plate probes set 4 according to NTD or an inclinometer

Supports for pipelines in polyurethane foam insulation

Pipe supports are used to hold elements of main networks. They are laid during the installation of pipe lines. Made from steel of various strength characteristics and corrosion resistance.

Pipeline support prices add up

• Wells
• Cast iron hatches
• Stairs for wells
• Accessories for wells
• Support plates for wells
• Storm water inlets
• Cast iron housings and manhole covers
• Gas carpets and components
• Locking devices for hatches
• Other products
• Hatches made of ductile iron and components
• Cast iron cable consoles
• Wells are structures that are designed for purification, control, inspection external sewerage and drainage systems. The main function of such special structures is the collection and accumulation waste water, rain, etc. The bottom of such wells is equipped with various trays and grooves for directing wastewater. These wells ensure unhindered migration of water into them. The role of sewer wells when performing repair and preventative work, such as flushing and cleaning the entire system, is very large. Depending on the functions performed, wells can be the following: storage, inspection, filtering, differential, rotary.

• Insulation
• Rockwool
• Paroc
• Xotpipe
• K-flex
• Energoflex
• Izolin
• Currently, there are a large number of pipes that are suitable for residential, industrial, administrative buildings; they supply heat, water, gas, and also have main gas pipelines with petroleum products. All of them require reliable protection - thermal insulation, waterproofing, protection from harmful effects environment etc. Why is this necessary? In order to extend the service life and quality of service of various pipelines, without which a full life is impossible these days. This section presents the insulation that serves reliable protection for pipelines and manufactured in modern production.

• Cranes
• Danfoss
• Broen Ballomax
• Taps serve as a device for regulating the flow of various working environment in the pipeline system, at any time they can be opened or closed or the pressure of the supplied liquid can be adjusted, which is very convenient. This design is quite easy to use and ensures a long service life, because The likelihood of failure is very small and minimal. Cranes come in different designs and types. Used in various systems. Due to its simplicity of design, operational reliability and durability, this locking device is very popular and is used in many industrial sectors - water supply, heating, gas supply, etc.

• Pumps
• Grundfos
• Pumps are a device that moves gases or liquids. In the present modern conditions life without pumping equipment It is simply impossible to imagine, this is confirmed by the fact that 20% of the world's electricity is used to operate pumping equipment. Pumps are divided into household and industrial, depending on the scope of application. Domestic pumps used in heating systems, sewerage and water supply, and industrial ones in cooling systems, water supply industrial installations, water treatment, supply and pumping of liquid supplied under high pressure.

• Zilmet
• Reflex
• This section presents expansion membrane tanks that serve as a reservoir for pumps and accumulators. When you choose a tank for heating system, it is necessary to pay attention to the membrane material, which must be durable and not be destroyed when exposed to aggressive environments and high temperature. Should be paid special attention on working conditions and main purpose expansion tank in the system. The certified products presented in this section are produced by the most successful companies that specialize in the production of these products.

• Fitting
• Locknuts
• Couplings
• Bends
• Transitions
• Threads
• Sgony
• Flanges
• Stubs
• Tees
• Bochata
• Welded parts of pipelines
• Fittings for steel and cast iron pipes began to be used for threaded connections highways and devices from the moment of use metal pipe to move the working environment, therefore, in our time, it is even more difficult to overestimate the importance of these connecting elements. Pipes and fittings have always been the basis of any pipeline, therefore, with the development of technical progress, technologies and types of steel and cast iron fittings have developed. The price of making a fitting depends on the materials used, their weight and purpose. A cast iron fitting is made by casting and installed for branches, turns, and transitions of pipes to another diameter, especially in cases where periodic disassembly of connections is necessary. Steel fittings primarily act as a welded threaded connector, as well as couplings and locknuts on fittings, and are produced mainly from a pipe blank on lathes. Most hydraulic devices such as heating devices, filters, distributors, automatic and control devices, etc. it is impossible to manufacture and connect to the pipeline without using steel and cast iron fittings.

• Cast iron pipes (Svobodny Sokol)
• Cast iron fittings
• Our product catalog includes cast iron styles and ductile iron pipes - socket and floor type, which are made of high-strength cast iron with nodular graphite with a nominal diameter of 80, 100, 125, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000 mm. Ductile iron pipes are manufactured 6 meters long, with a rubber sealing ring, with an external and internal coating that complies with the standards of GOST R ISO 2531, EN 545. Socketed pipes with such types of connections as: TYTON, TYTON sewerage and RVS(RJ) are available for sale. Tyton (Tyton) - bell joint for a sealing ring with a working pressure of 3.0-6.4 MPa; RVS(RJ) - bell-and-lock joint for a rubber sealing ring with a working pressure of 2.5-8.8 MPa; High-strength cast iron with nodular graphite - ductile iron has differences from gray cast iron with a lamellar form of graphite, such as higher strength, which is close to the properties of low-carbon steel, and higher resistance to cracking. To obtain such properties, ductile iron was obtained by modifying liquid cast iron with magnesium and various additives. As a result, a metal was obtained in which graphite is in the form of balls, which makes it possible to increase the ductility and strength of pipes and fittings.

Water and gas pipes will be made of steel for a long time to come. Alternative options– metal-plastic water conduits, ceramic, can be used only in certain areas: local water supply systems, free-flow sewerage, communications inside the building. However, when above ground installation the pipeline is exposed to too much weather. This eliminates the use of plastic or other products.

Characteristics of VGP

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

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

Advantages:

• high strength, which allows the product to be used with any installation method and in any area;
• oxygen and gas impermeability are precisely those properties due to which gas pipelines are and will be constructed only from steel products;
• low coefficient of expansion - temperature and moisture changes do not affect the material. The pipeline does not expand, which allows the use of rigid fastening and does not require the installation of compensation devices;
• durability - with proper maintenance it is 50 years;
• affordable price.

Flaws:

• quite heavy, which makes installation difficult and requires large quantity fasteners;
• the need for preventive maintenance - metal accumulates electricity;
• the need for thermal insulation when laying in the ground - the freezing liquid expands, while the parameters of the water pipeline remain unchanged. This leads to damage and ruptures.

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.

Because we're talking about O water pipes, then instead of the internal diameter, an indicator such as nominal diameter is used. It is given in both inches and mm.

Product varieties

Different way pipeline laying and different conditions operation assume great friend from a friend technical specifications. The rental company produces several modifications.

Classification by material

The raw material for 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:

• water pipelines made of steel of ordinary precision - only the mechanical qualities of the product are controlled. Chemical composition steel is not being investigated. The products are used for household communication systems;
• pipeline made of high-precision steel - galvanized steel is used in manufacturing, mechanical properties are standardized by GOST 3262-75. The 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 pass different levels control. As a result you get:

• black – without galvanizing, more often used when laying gas lines;
• galvanized - finished products are galvanized - immersed in molten zinc. Forms on the inner and outer surfaces of the product. protective layer, protecting against corrosion. Large water mains are constructed from galvanized VGP.

Release form

Water and gas pipes GOST 3262-75 are produced:

• with threaded ends (knurling or cutting) - 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 - a welded connection is assumed.

Resistance to hydraulic pressure

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

• light - the operating pressure of the liquid should not exceed 25 kg/kV. cm;
• conventional - assumes the same pressure, but allows water hammer;
• reinforced - pressure can reach 32 kg/kV. cm.