About that, what is VGP pipe, everyone knows, who at least once faced repair work of the household pipeline. Rolled steel, which is used for carrying out pressure head, pressureless water- and gas pipelines, is on the market in a wide range, and, obviously, is not going to give up its leading position in plastic pipes. VGP pipes are especially successfully used in areas, where the effects of corrosion are minimized: on above-ground sites and indoors. However, galvanized steel products are able to withstand corrosion quite well, even in the most adverse conditions.
VGP steel pipes are used for installation of gas and water mains with different operating conditions
VGP steel pipe: what it is?
Pipes, classified by the abbreviation VGP, are considered very strong and durable. Their rigidity is equated to the qualities of all-metal beams of similar diameter. The purpose of the steel VGP pipe lies in the interpretation of the name - "water and gas". In accordance, these products are used to create pipelines for gas and water: as pets (household), and trunk.
Advantages, which have water and gas pipes, can be called the following:
- low rate of linear expansion. VGP pipes are not deformed under the influence of temperatures, approaching boiling water. They are able to withstand such temperatures, in which the polymeric materials begin to soften and melt. Also, the steel pipe does not deteriorate when the coolant freezes (liquids);
- high strength. The strength characteristics of the GDP of the steel pipe are higher, than data from copper and polypropylene products. Their permissible internal pressure limit allows the use of steel pipelines in pressure networks. Galvanized VGP pipe is also resistant to corrosion;
- thermal conductivity. The media in steel pipes maintain the required temperature for a long time;
- tightness. Transportation of gaseous and volatile substances is allowed, as well as acids and other chemically active components.
Ordinary steel and non-galvanized pipes are quickly covered with rust
Importantly! On the other hand, high thermal conductivity can cause heat loss in the system, but this shortcoming can be easily overcome with insulating materials.
What is the difference between VGP pipe and electric welded pipe?
Of course, such a question is not entirely correct, but for a layman it is quite important. In general, VGP pipe is a kind of category of electric welding products. Visually, the water pipe differs from the electric welded only in size, but the state standard dictates different requirements for these two types of pipes. Electric welded pipes are more often used in main constructions, and can also serve as support columns, frame constructions for furniture, fences or fences. As for the production of GDP, galvanized steel can be used in the manufacture of electric welding pipes.
The main differences between these types of pipes, according to the corresponding GOSTs, are presented in the table.
Table 1
| Steel VGP pipe: GUEST 3262-75 | Straight seam electric welded pipe: GUEST 10704-91 (TU according to GOST 10705-80) |
| Normative document dictates the conditions for the assortment and production of GHP pipes with a conditional passage from the remote control 6 to DU 150 | Normative document dictates the conditions for the production and range of straight-seam pipes, with outer diameter 10-1420 mm |
| Maximum permissible deviations (Considered on the outer diameter) Not more 0,4 mm for d <48 mm No more 0,8% for d >48mm | Maximum permissible deviations (are considered on external diameter): Not more 0,4 mm for d <50 mm |
| The maximum allowable deviation in wall thickness: 15% | The maximum allowable deviation in wall thickness: 10% |
| Maximum hydraulic pressure: 2,4 MPa - ordinary pipes | Maximum hydraulic pressure: 6 MPa - at d 102 |
Production of analogs of steel VGP of a pipe according to GOST is allowed 10704-91 provided that they fully comply with the standards.
Welded pipes VGP can have as a spiral, and a straight seam
VGP pipe: characteristics and assortment
The range of VGP pipes by product type is divided into two types: VGP pipe is black and galvanized. The range includes galvanized models to a number of high-precision pipes. Further classification is made by the length of the products, wall thicknesses, outer diameter and remote control (decryption - specific or conditional passage).
The last indicator - DU -indicates the capacity of the selected product. The range includes pipes with a conditional passage in the range 6-150. The outer diameter under different conditions varies from 10 mm (for remote control 6) to 165 mm (for remote control 150).
Conditional passage is usually denoted in inches. VGP pipe, Remote control which means "20", will be recorded in catalogs as a product with an inner diameter of? in. And all the additional materials (fittings, couplings, plugs, etc.) will also be required with value? in.
Translation in inches of other remote controls:
- Pipe VGP DU 8 =? «;
- ДУ 15 =? «;
- ДУ 25 = 1 «;
- ДУ 32 = 1? «;
- ДУ 40 = 1,5 «;
- ДУ 50 = 2 "etc.
The rigidity of the GDP of the pipe is affected by another indicator, which determines the range of products - wall thickness. It turns out, how thick was the steel sheet, from which the pipe was later welded. The ratio of the conditional passage to the outer diameter of the GDP of the product also depends on the wall thickness.
Pipe diameter is an important indicator, which determines its bandwidth
The assortment includes such types of pipes on wall thickness:
- ordinary - wall thicknesses vary from 2 to 4,5 millimeters;
- light - from 1,8 to 4 millimeters;
- reinforced - from 2,5 to 5,5 millimeters.
The only difference, which distinguishes galvanized VGP pipes from simple products, in the production of which black steel is used - their weight. Galvanized pipes have a larger on 3-5% mass due to the presence of a thin anti-corrosion coating. In everything else, the range of VGP pipes extends to galvanized models.
Certificate for VGP pipe: what it is and why it is needed?
Certificate, outstanding manufacturer, needed to protect the consumer from the purchase of substandard goods. The presence of a certificate of conformity indicates that, that the given manufacturer adheres to all norms, registered in a specific Guest. Interesting, that the certificate of conformity for VGP pipes is issued voluntarily: water and gas products are not subject to mandatory certification. Such a certificate is issued after passing tests in the laboratory, including hydraulic.
Importantly! If the certificate is issued for galvanized products, the document must specify the method of galvanizing - "hot" or "cold".
Another document, has a positive effect on the trust of the buyer - it is a hygienic certificate. The conclusion on passing of sanitary-and-epidemiological examination fits into it. The procedure is performed in a limited time using standard expert methods. Certificate, received by the company, applies to the entire range of products.
When choosing pipes for installation of the gas pipeline system (water supply) it is necessary to start from the degree of compliance of the capacity of the supplier with the conditions of the state standard and from personal requirements. Galvanized pipes are also suitable for household pipelines, and black steel pipes. If the system operation requirements are increased, then galvanized steel will be the best choice.