The wedge gate valve is installed in pipelines as equipment that provides shutoff of the working flow of the medium, perpendicular to which the lock moves. The passage to the device is closed due to the translational movements of the shutter in the perpendicular direction from the moving medium.
The wedge gate valve got its name because of the shape of the lock in its design, in which the arrangement of the seals is made at an angle to each other. The closing mechanism is performed by turning the handwheel to the right. The body of the device is made straight, which prevents the possible accumulation of various deposits on its walls.
According to the type of gate valve, wedge valves are:
• with one-piece rigid wedge;
• with elastic (with lateral guide surfaces);
• with a wedge made up of two discs.
The use of a rigid wedge in locking devices with small diameters makes the design more reliable and tight. However, with significant fluctuations in the operating temperature of the transported medium in the equipment, jamming of the device in the housing may occur.
Valvewedge is used mainly on horizontal pipelines. The flywheel of the device should be located on top. The spindle must only be in a vertical position.
By the type of connection of wedge valves to the pipeline, they have varieties:
• for welding;
• coupling;
• Flanged gate valve.
Equipment of this type is made in various ways: casting, forging or welding. Stamped gate valves have a body of parts connected by welding. At the same time, they have a much smaller size and weight. Devices of this type are used for both gaseous and liquid media with temperatures up to +300°C. The tightness class of stamped-welded gate valves is determined in accordance with GOST 9544-2005 and has the designation: B, C, D.
Wedge-type locking devices are used to transport natural and liquefied gas, steam, petroleum products, chemically active and aggressive liquids.
The gate valve is manufactured in the following modifications:
• SA series electric drive;
• with K series gearbox;
• with telescopic stem extension.
Each of all types of this equipment has its advantages and disadvantages, as well as the scope. The advantages of wedge gate valves are, first of all, in the simplicity of design, durability, reliability, maintainability, resistance to environmental influences, etc. Small hydraulic resistance of these locking devicesmade them indispensable for pipelines with a medium that moves at high speed. All these qualities make this fitting very popular in industrial enterprises and public utilities. The body of wedge gate valves is made full-bore, that is, there is no narrowing of the diameter of the flow section. However, in some cases, narrower devices are used, which makes it possible to achieve a significant reduction in the forces and torques of control systems, as well as to reduce the weight and overall dimensions of the equipment.
