The crane spherical flange for gas. Gas ball valves
During the operation of pipelines, the function of shutting off the flow of the transported medium must be provided. This condition is important for both industrial highways and domestic systems.
This task can be ensured by the installation of special fittings, which completely block the movement of gas in the pipeline.
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Classification of ball valves for gas
Ball valve used for correct and safe work main gas pipeline, is a shut-off valve, in which the passage is blocked by a blocking part of a spherical shape. The angle of deviation from the working axis is 90º.
Ball gas valves are divided into classes depending on performance characteristics.
By functional purpose there are:
- Locking. Are intended for opening or closing of passage with a working environment.
- Distribution. Distribute the flow of the gas pipeline in certain directions. They may or may not be multi-way.
According to the type of the flowing part of the body:
- Full bore valves - in them the diameter of the flow area is the same or greater than at the inlet.
- With a narrowed passage - in the body of such valves, the passage sections are narrowed, which makes it possible to reduce the efforts of the control mechanisms, as well as to reduce the size of the valve.
According to the mounting method, with evenly spaced bolt holes.
Most often, flanged gas valves are used in the installation of a main pipeline DN 50 or more, carrying oil products and gas. Flange fasteners are considered to be among the most durable, and flange gaskets can provide a high degree of tightness.
Fittings are mounted using a special fitting (), in which one end has an internal or external thread.
Couplings have an internal thread at both ends, they are installed in the pipeline using a wide tube of small length. As well as flange are easy to use, in addition, they are small in size and extremely practical.
If necessary, such a locking unit can be dismantled, disassembled and troubleshooted. Apply to the main pipeline DU 15 - DU50.
Welded gas valves are mounted using welding machine. The disadvantage of this method is that the crane will not be able to be dismantled in the future. To eliminate the drawback, a flange connector is installed at both ends of the valve. The welded method is most widely used in pipelines DU50.
Combined combine different ways fasteners (flange, coupling).
According to their design, cranes are:
With a floating ball, when the rib is not rigidly connected to the spindle and can move. Under the pressure of the medium from the inlet side, the plug is pressed against the ring with a seal and closes the pipe. Such a locking knot used in highways with a diameter of not more than 20 cm.
With a ball in the supports, when the cork is movable and fastened in the supports. The pressure of the working medium on the saddle presses the plugs to the surface in the form of a sphere. The locking lug can be equipped with bearings.
Advantages of ball valves for gas
The ball valve is a very important part of the main pipeline, which is not subject to frequent replacement. Most of the marked valves have a long service life.
Temperature environment, in which the ball valve for gas normally works, ranges from -60ºC to +80ºC. But the working environment can be even larger -60ºC to +200ºC.
The indisputable advantage of this type of fittings is that the shut-off node can be easily installed and just as easy to maintain.
Gas belong to the tightness class "A". They are durable and able to reliably block the pipeline.
Overview of the ball valve "VALTEC" for gas (video)
Materials for manufacturing
When installing a gas main pipeline, industrial or domestic, several types of valves are used. The most common. The reason for this popularity lies in the durability of the material: brass easily copes with temperature changes and high pressure working environment.
Brass faucets with a socket connection are perfect for small diameter pipes. Special Teflon or stuffing box sealing ensures reliable tightness of the fittings. If suddenly there is a suspicion of a gas leak, before replacing the assembly, you can simply tighten the nut by pressing the seal.
In 90 cases out of 100 the gasket will completely close the leak and the gas ball valve will work correctly again. Thanks to these design features, the crane has long term operation.
In addition to brass, there are also steel Ball Valves for gas pipelines. Such fittings are quite reliable: there are no docking nodes and connectors in them, since the part is one-piece. Leakage of gas from the tap is unlikely, for complete safety it is necessary to make sure that the connection with the pipe itself is tight.
Steel is a strong and durable material, so a steel crane will last a long time.
Installation and maintenance are not difficult, they are easy to manage. Steel ball joints can handle high pressure with ease and high temperatures working environment. Unlike brass, steel cranes are much cheaper.
The subtleties of choosing a ball valve
Especially for the gas main pipeline, this is a responsible matter. There are subtleties that you need to pay attention to first.
So, let's start by inspecting the hull. On him there should be no visible defects in the form of dents, scratches or curvatures. A marking is usually applied to the body, which must exactly match the technical documentation for the valve.
If the fittings are suspiciously cheap, it means that the manufacturer used metal impurities instead of zinc or steel. Such a gas ball valve can break at the most inopportune moment.
Next, you need to pay attention to the most important part of the crane - the ball itself. This element receives the greatest load during the operation of the valve, therefore, it must be executed perfectly. As a rule, the ball is coated with a layer of anti-corrosion agent.
If some spots are visible on the surface of the core that cannot be wiped off with a rag, the ball itself is dull, roughness and defects are noticeable on it, then the reinforcement is most likely of poor quality. For the main pipeline with gas, such a shut-off unit is not suitable.
Ball valve gas GShK with floating flanges provides installation of the valve in any position and does not require angular alignment of the mounting holes of the pipeline flanges.
Flanged connection to the pipeline enables multiple mounting and dismounting of the ball valve, reliable sealing of the joints and the possibility of tightening them.
Cranes are produced from steel grades ST-20 and 09G2S. The temperature of the working environment is from -30 to +50 C, the ambient temperature is from -60 to +45 °C.
Flanged ball valves GShK are produced both for natural gas and for LPG with Du from 15 to 100, under a working pressure of 1.6 or 2.5 MPa.
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Climatic versions of flanged ball valves:
Moderate climate - "U1" according to GOST 15150 (with ambient temperature from -40°С to +45°С). Parts material: structural carbon quality steels, aluminum alloys.
Cold climate - "HL1" according to GOST 15150 - "NORD" (with ambient temperature from -60°C to +45°C). Parts material: cold-resistant steels, aluminum alloys.
Depending on the conveyed medium of the pipeline:
Unpurified air from mechanical impurities and non-aggressive natural gas according to GOST 5542-2014 - G
- non-aggressive natural gas purified from mechanical impurities according to GOST 5542-2014, vapor and liquid phases of liquefied hydrocarbon gases according to GOST 20448-90 and GOST 27578-87, oil products - AND
Ball valve GShK flanged - technical parameters:
Flanged ball valves are installed in any position and do not require angular alignment of the mounting holes of the pipeline flanges. Ball valves manufactured by Ex-Forma do not require any Maintenance or revisions during the entire service life. At the request of the customer, LLC PKF "Ex-Forma" supplies ball valves with mating flanges, fasteners, and gaskets. It is possible to complete with MEOF electric drive.
Ball valve GShK flanged DN15-DN100 - connecting dimensions and dimensions:
Nominal pressure 1.6 MPa (16 kgf/cm² )
| Designation | DN | Lc | L | A | D | D1 | D2 | d | h | b | n | Weight, kg |
| GShK 15F-16 | 15 | 110 | 150 | 88 | 95 | 65 | 45 | 14 | 2 | 14 | 4 | 2,3 |
| GShK 20F-16 | 20 | 120 | 150 | 88 | 105 | 75 | 58 | 14 | 2 | 16 | 4 | 3,0 |
| GShK 25F-16 | 25 | 120 | 150 | 100 | 115 | 85 | 68 | 14 | 2 | 16 | 4 | 4,3 |
| GShK 32F-16 | 32 | 140 | 150 | 100 | 135 | 100 | 78 | 18 | 2 | 18 | 4 | 4,83 |
| GShK 40F-16 | 40 | 160 | 225 | 115 | 145 | 110 | 88 | 18 | 3 | 19 | 4 | 8,56 |
| GShK 50F-16 | 50 | 156 | 225 | 115 | 160 | 125 | 100 | 18 | 3 | 21 | 4 | 9,7 |
| GShK 65/50F-16 | 65 | 160 | 225 | 115 | 180 | 145 | 122 | 18 | 3 | 24 | 8 | 11,96 |
| GShK 80F-16 | 80 | 283 | 407 | 225 | 195 | 160 | 117 | 18 | 3 | 26 | 8 | 23,9 |
| GShK 100F-16 | 100 | 230 | 407 | 235 | 236 | 180 | 158 | 18 | 3 | 23 | 8 | 27,5 |
| GShK100/80F-16 | 100 | 230 | 407 | 223 | 215 | 180 | 156 | 18 | 3 | 23 | 8 | 24,3 |
Nominal pressure 2.5 MPa (25 kgf/cm²)
| Designation | DN | Lc | L | A | D | D1 | D2 | d | h | b | n | Weight, kg |
| GShK 15F-25 | 15 | 110 | 150 | 88 | 95 | 65 | 45 | 14 | 2 | 14 | 4 | 2,3 |
| GShK 20F-25 | 20 | 120 | 150 | 88 | 105 | 75 | 58 | 14 | 2 | 16 | 4 | 3,0 |
| GShK 25F-25 | 25 | 120 | 150 | 100 | 115 | 85 | 68 | 14 | 2 | 16 | 4 | 4,3 |
| GShK 32F-25 | 32 | 140 | 150 | 100 | 135 | 100 | 78 | 18 | 2 | 18 | 4 | 4,83 |
| GShK 40F-25 | 40 | 160 | 225 | 115 | 145 | 110 | 88 | 18 | 3 | 19 | 4 | 8,56 |
| GShK 50F-25 | 50 | 156 | 225 | 115 | 160 | 125 | 100 | 18 | 3 | 21 | 4 | 9,7 |
| GShK 65/50F-25 | 65 | 160 | 225 | 115 | 180 | 145 | 122 | 18 | 3 | 24 | 8 | 11,96 |
| GShK 80F-25 | 80 | 283 | 407 | 225 | 195 | 160 | 117 | 18 | 3 | 26 | 8 | 23,3 |
| GShK 100F-25 | 100 | 234 | 407 | 235 | 236 | 190 | 158 | 22 | 3 | 25 | 8 | 27,45 |
Due to the presence of an all-welded spherical body, the design eliminates the possibility of gas leakage, which is possible with other types of connection. With a symmetrical structure, the crane can be mounted in any position. The handle of the crane is covered with a protective paint and varnish composition, which excludes the impact of aggressive environments and corrosive processes. The nut of the shut-off gas fittings has a galvanized coating, which makes it possible to prevent the appearance of static electricity and the possibility of ignition of the treated section of the pipeline through which the gas passes.
Crane types
According to the material of manufacture
- Brass. The body and stem of the gas valve are made of nickel-plated brass, the ball is made of chrome-plated brass. The lever is made of steel. Brass cylinder heated in induction furnace up to 700 °С, acquires its final shape in one working stroke of the press. This guarantees the homogeneity of the material structure over the entire area of the product and ensures reliability. The valve for gas, made of brass, is not subject to corrosion.
- Steel. The welded body, lever and gasket holder are made of structural or carbon steel (grades 18G2A, St37-2, C35, etc.). The ball, rod and spring are made of stainless, including acid-resistant, steel (grade X20Cr13, X5CrNi1810, etc.), spring steel or cast iron. AT gas tap There are no bolted connectors in this design. This eliminates the possibility of gas leakage caused by the dynamic load of the pipeline.
By seal type
- With polyurethane seal. Such a ball valve is designed to operate in an environment of natural gas not purified from mechanical impurities (GOST 5542-87).
- With fluoroplastic seal. This type of gas shut-off device is designed to operate in an environment of untreated natural gas (GOST 5542-87), as well as liquefied hydrocarbons (GOST 20448-90 and GOST 27578-87).
Ball valves for gas according to the diameter of the passage DN 10-50 mm:
Ball valves for gas with a passage diameter DN over 50 mm:
