Gate valve is a valve where the disc moves in the vertical direction along the centerline of the pathway. Gate valves are mainly used for cutting off in the pipeline.
One of the most common classifications can be divided into wedge gate valves and parallel gate valves according to the configuration of the sealing surface.
Wedge gate valve can be divided into: single disc type, double disc type and resilient disc type; parallel gate valve can be divided into single disc type and double disc type.
The sealing surface of the parallel gate valve is perpendicular to the axis of the pipe, to je, the two sealing surfaces are parallel to each other import gate valve.
The sealing surface of wedge gate valve is at an angle to the axis of the pipe, to je, the two sealing surfaces into a wedge-shaped gate valve. The size of the angle of inclination of the wedge depends mainly on the temperature of the medium, generally the higher the working temperature, the larger the angle taken should be, in order to reduce the possibility of gate wedging when the temperature changes.
Farpro will explain in detail the difference between parallel and wedge gate valves:
Features of Parallel Gate Valves
Parallel gate valve is the most common double disc type, in order to close the valve body and the gate between the two sealing surface contact tight, often used in the two gate plate sandwich with double-sided thrust wedge.
In this way, when closing the valve, the double-sided thrust wedge contact with the bottom of the valve body is gradually stressed, pushing open the double gate plate so that the gate sealing surface and the valve body sealing and tight. This kind of double disc parallel gate is usually applied to the working condition that does not need to open and close frequently, and keep the gate fully open or fully closed.
Usually, in the case of direct connection with the pipeline, it is recommended to use the parallel gate valve, which has the advantages of compact structure, mala težina, mala veličina, easy maintenance, convenient and flexible operation, itd.
Features of Wedge Gate Valves
Klinasti zasun have single/double disc wedge gate valve. The advantages of double disc wedge gate valve is sealing while the angle of the accuracy requirements are low, temperature changes are not easy to make the gate wedge, sealing surface wear can be compensated by adding gaskets.
The disadvantage is that the structure is complicated, easy to stick in the dry medium, more mainly the upper and lower baffle plate is easy to fall off after years of corrosion.
Stoga, the single disc wedge gate valve is used in large numbers due to its simple structure and reliable use, especially after changing to a resilient gate, which can produce a slight elastic deformation to compensate for the deviation produced in the processing of the sealing surface angle.
In general, the stem of wedge gate valve is tempered and surface nitrided to have good corrosion resistance and anti-scuffing. The gate and seat seal are made of hard alloy overlay welding, which is wear-resistant, high temperature resistant, corrosion-resistant, good anti-scuffing performance and long service life. The valve body material variety is complete, packing, gasket according to the actual working conditions or user requirements reasonable optional, can be applied to a variety of pressure, temperature and media working conditions.
Wedge gate valve is widely used in electric power, petroleum, kemijski, metalurgija, rudarstvo, sewage treatment and other industrial fields, especially in the power station ash removal can play a huge role in coal washing plant equipment.