Description of valves. Shut-off valves
gate valves- this is a type of shut-off pipeline valves used at a variety of facilities: both small utility and technical, and large main pipelines. They are necessary in order to ensure complete blocking of the movement of the working medium: hot and cold water (drinking and technical), neutral liquids, as well as sewage.
Gate valves are especially preferred if the pipe diameter is more than 150 mm.
Experts know that valves are not used to control the flow of the working medium. The device has only two positions: "closed" and "open".
There are special valves designed to transfer special media - alkalis, hot chemicals, acids, petroleum products. They can withstand up to 300ºС at pressures up to 20MPa. In this case, the working bodies of the valve are made of special synthetic materials. In addition, the valve body is protected from negative external influences using various coatings.
Gate valves have many advantages over other types of valves.
1. They have low hydraulic resistance.
2. Gate valves can be used in a wide range of temperatures.
3. Gate valves have a simple structure and require minimal maintenance.
4. Due to the short length of the valves, they can be used even in rooms with compact dimensions.
But there are also disadvantages:
1. The transfer of the valve to one of the two positions takes a lot of time - not all valves can be used where a quick shutdown of the flow of the working medium is required.
2. When opening, some types of valves increase their size by about 1 pipeline diameter. This applies to devices with a rising spindle.
3. When the sealing parts are worn out, it can be quite difficult to replace them, usually a complete dismantling of the valve is required.
Exist different types valves, which are classified according to several criteria.
1. Depending on the opening of the sealing ring - narrowed and full bore.
2. According to the shutter design:
. Wedge. In these types of devices, the locking element is made in the form of a wedge. They, in turn, are divided into valves with an elastic, rigid and double-disk wedge.
. Parallel. In them, the locking element consists of two parallel discs.
. Gate. A metal plate is used to shut off the flow. If it is made of special alloys, such a valve will withstand an aggressive working environment.
. Hose. When closing, the flexible hose is pinched by the spindle. Suitable for use in the food or chemical industry.
3. By type of control:
. Manual (with a simple handwheel or with a gearbox)
. With electric drive.
. With a double-acting pneumatic actuator.
4. Depending on the location of the running unit:
. With fixed spindle.
. With retractable spindle.
5. Depending on how the stop valves are connected to the pipeline:
. Under welding. Rarely used. Their diameter should be similar to the diameter of the pipe.
. Flanged - the most popular option. They have a simple design and are quick and easy to install.
In the assortment of the SinStroy company, you can choose the type of valves you need. We offer high-quality, reliable and wear-resistant steel and cast iron gate valves with a rubberized wedge, as well as gate valves.
Bugatti Bugatti
The modern arrangement of pipeline systems for various purposes cannot be imagined without high-quality pipeline parts and fittings. It changes the parameters of the passage section, which allows it to control the flow of moving substances and various media. Shut-off valves is one of the classes of functional purpose, which belongs to fairly common types of pipeline fittings. Among professionals, it has been divided into test-bleed and control-bleed fittings, which are used to determine the level of liquid in various containers, take sample material, discharge unwanted air from the upper sectors of the tanks, as well as for the design of drainage and sewer systems.
Shut-off valves will block the flow of the medium or significantly change its intensity. A significant feature of this type is its high tightness, which manifests itself when a liquid, powder or gaseous medium is blocked in consistency. This avoids unwanted leaks and the loss of valuable raw materials, as well as preventing serious accidents.
Pipeline accessories
Shut-off valves have several categories in the form of valves, taps, gate valves, valves and gates. High strength and significant resistance to aggressive media make it possible to use it as a reliable and proven material. Pipe fittings are sufficiently resistant to corrosion, which prolongs their service life and reduces the likelihood of repair work. Depending on the purpose, it is made of various synthetic polymers, steel, brass, titanium.
Pipeline fittings have a fairly simple design, which allows you to quickly and efficiently install the system, if necessary, perform service maintenance and additional repairs. The stable case withstands static and dynamic loads well, endures the harmful effects of aggressive chemical compounds. The convenient design allows you to adjust the flow, both automatically and manually. That is why the use of such fittings in any industry will leave only positive feedback, and provide excellent functioning results.
Buy valves
Before purchasing a shut-off valve, it is necessary to determine its purpose and basic operating conditions, the composition of the working environment and load indicators. Be sure to take into account the temperature indicator of the substance being moved. It is necessary to determine the mass indicator and dimensions, as well as the functional purpose of the drive.
You can buy gate valves after viewing the full catalog of products on the site. Their sale is carried out together with delivery at the expense of our own fleet, which will significantly reduce the financial costs of the client. In the price list, you can view the most complete characteristics of the selected product, which are characterized by different configurations in accordance with the scope of application.
Gate valves are made of high quality materials, which allows you to effectively fulfill your goals. For each purchase, the client receives quality certificates, which indicate the compliance of the goods with standard production indicators. You can always buy gate valves at an affordable price, which corresponds to high quality. They will serve in the system for a long time without requiring additional work from the client.
Gate valves are specialized mechanisms that are one of the most popular types of shut-off pipeline valves. It is used to stop the supply of the working medium through the pipeline by shutting it off.
Gate valves are quite simple in design, and also have a fairly low hydraulic resistance. The locking element reciprocates into the pipe perpendicular to the transported medium. As a rule, valves have two positions - closed and open. There are no intermediate positions, so it is not possible to control the flow with their help. Gate valves are especially often installed on a pipeline in which a liquid or gaseous medium moves at high speed.
Gate valves can be parallel, gate and wedge, depending on the design of the gate.
Our range of gate valves is quite wide, and today it is represented by steel and cast iron gate valves, wedge and parallel specimens.
As for the method of attaching valves to the pipeline, there are several main methods: using a coupling, flanges or welding. In the most critical cases, the welding method is used, since it provides maximum tightness and reliability of the connection.
Typically, the diameter of the valve bore is equal to the internal diameter of the pipeline, however, in some cases, it may be necessary to narrow it, so narrowed or socket valves are used. Gate valves are used in industry in cases where complete tightness of the gate in the “Closed” position is required when working with various media. In some cases, gate valves may be replaced by valves or faucets.
Gate valves are most often made of cast iron, steel or non-ferrous metals.
Pipelines for industrial use often require only steel gate valves, which are the most common. The locking element is located at an angle of 90 degrees to the working environment. The steel valve body can be cast, forged, stamped or welded. Valves made of stainless steel have a long service life and are resistant to corrosion.
Cast iron gate valves are also often used as shut-off valves, and the diameter of the through hole can reach 3000 millimeters. Like steel gate valves, cast iron products are extremely simple in design, so long service life, easy maintenance and operation are guaranteed. To give special strength to the metal, alloying elements are added at the production stage. While steel gate valves are used in a variety of media, ranging from oil to powder mixtures, cast iron works best in pipelines transporting waste, drinking hot and cold water and steam up to 225 degrees. However, cases of successful use of cast iron valves in the petrochemical industry are also known.
gate valves designed to completely block the flow of the working environment. Gate valves are widely used in water supply systems, oil and gas processing lines, in power systems on pipelines with nominal diameters from 50 to 3000 mm, at operating pressures from 0.4 to 20 MPa and temperatures up to 600 degrees Celsius. In some cases, special valves are manufactured and for more high pressures. On pipelines with diameters greater than 150 mm, gate valves are used more often than other types of valves.
In the warehouse of BK-Armatura, high-quality gate valves are always available: 30ch6br, 31ch6br, 30ch7bk, 30ch906br, 30s41nzh, 30s15nzh, 30s64nzh, ZKL 2-16, 30s541nzh, 30s941nzh, MZV (30ch39r), MZVG.
Depending on the design of the shut-off body, the valves are divided into wedge and parallel.
Wedge gate valves- 31ch6br, 30s41nzh, 30s941nzh, 30s15nzh, 30s64nzh O-rings are located at a slight angle, forming a wedge. Wedge gate valves are manufactured with a solid (rigid or elastic) wedge or a composite double-disk wedge formed by two disks located at an angle to each other, thus forming a wedge. The use of a rigid wedge in gate valves of small diameters creates a reliable design with high tightness of the locking element. With increased requirements for tightness, a double-disk shutter is used.
Gate valves parallel- 30ch6br, 30ch7bk, 30ch906br: O-rings are parallel to each other.
Parallel gate valves can have a gate in the form of a single disk or sheet (slide), or in the form of two disks with a spacer wedge or spacer spring located between them. Gate valves can be with retractable and non-retractable (rotating) spindle.
So that the valve does not let water through, the discs are tightly rubbed against the rings. When the handwheel is rotated to the right, the spindle together with the disks rises and opens the valve. In the upper part of the spindle under the thread there is a stuffing box cover, and under it in the annular channel of the body cover there is a stuffing box packing.
Rising stem valves- 30s941nzh, 30s41nzh.
Steel valves - 30s41nzh, 30s941nzh - are made with a cast body and cover, and are used at pressures up to 1.6 MPa at a working medium temperature of up to 450 degrees Celsius. When opening and closing such a gate valve, the spindle performs translational or rotational-translational (screw) movement, and the spindle thread and nut are outside the cavity of the valve.
The advantages of this design are the absence of harmful effects of the working environment on the chassis and free access for it. Maintenance, and consequently less wear of the gland seal and more high reliability threaded pair and gland.
Gate valves with non-rising stem- MZV, MZVG, 30h39r - when opening and closing the valve, the spindle only rotary motion, and the lead thread is inside the cavity of the valve in contact with the working medium. Such gate valves are applicable for pipelines transporting mineral oils, oil and water, not clogged with solid impurities and providing lubrication of the friction pair "spindle - running nut".
The advantage of this design is the lower construction height, which makes it expedient to use them for underground utilities, wells, oil wells, etc. Gate valves MZV and MZVG have proven themselves perfectly working in various (harsh) climatic conditions.
Cast iron gate valves- 30h6br, 30h39r for cold and hot water are used for pressures up to 1.0 MPa at a temperature of the working medium up to 225 degrees Celsius.
Like steel gate valves, this type of pipe fittings is distinguished by its simple design and low hydraulic resistance. Cast iron gate valves are made from cast iron, to which they are added in order to give certain physical properties alloying elements. Material for production - gray cast iron. The main constituents of cast iron are iron and carbons. The price of cast iron valves is more acceptable than steel ones.
Valves for gas- 30s41nzh and 30ch7bk.
Cast iron gate valve 30ch7bk is used as locking device on gas pipelines low pressure Ru-0.6MPa. The working medium of the valve 30ch7bk: natural and fuel gas at temperatures up to +100 degrees C.
The tightness of the gate according to the class "A" GOST 9544-93.
Gate valve steel wedge two-disk 30s41nzh for gas
PN-1.6 MPa, with a rising spindle, is designed for installation as a locking device on pipelines for the transportation of non-aggressive liquid and gaseous media, in relation to which, the materials used in the valve are corrosion-resistant.
Shutter tightness: class "A" GOST 9544-93. These gate valves can be used not only for gas, but also for other non-aggressive and semi-aggressive media.
Gate valves for electric drive- 30ch906br, 30s941nzh, 30s927nzh.
One of the common types of pipeline valves designed to shut off and regulate the flow of the working medium, as well as to prevent an emergency, is a valve with an electric drive.
Electric gate valves are used in the oil and gas industry, in agriculture, as well as in public utilities. The advantages of using electric gate valves: a) high speed of shutting off or opening the flow of the working medium; b) durability of the structure; c) reliability. Gate valves can be equipped with both and.
It is possible to control these gate valves not only from a remote control, but also not directly at the location with a manual override. When installing gate valves with an electric drive, it is necessary to take into account the presence of a power source, which is not always possible in certain sections of the mains.
Gate valves have the following advantages: relatively small building length, direct flow, low odds hydraulic resistance, the possibility of supplying the working medium in any direction, the efficiency of use for large diameters, sufficient tightness of the shut-off body, the possibility of using it in a wide range of working media, temperatures and various operating conditions.
The disadvantages of gate valves are: a large construction height, due to the required value of the full stroke of the wedge, a significant opening and closing time, inefficient operation with incomplete opening, wear of the sealing surfaces when moving the wedge or discs and the difficulty of repairing them during operation, the difficulty of using a bellows instead of a stuffing box, a significant mass .
Gate valves are attached to the pipeline using, or by welding. Welded connections are more reliable than flanged ones, and therefore are used in the most critical cases - for example, in power systems with high temperatures and pressure of the working environment.