The opening and closing part of the Wedge Slider are the gate, the movement direction of the gate is perpendicular to the fluid direction. The wedge slide valve can only be fully opened and fully closed, and cannot be adjusted and throttled. The gate has two sealing surfaces, the two sealing surfaces of the wedge slide valve normally form a wedge. The wedge angle varies depending on the valve parameters, usually 5 degrees. If the media temperature is not high, it will be 2°52′. The wedge gate valve gate can be integrated and called a fixed gate. Or it can be made into a gate that can produce deformation traces to improve its manufacturability and compensate for the deviation of the angle of the sealing surface during processing, which is called a flexible gate.
Wedge valve working principle
When the gate valve is closed, the sealing surface can only be sealed by the pressure of the medium. That is, only the pressure of the medium pushes the sealing surface to the other side of the seat to ensure the sealing of the sealing surface, which is called self-sealing. Most gate valves are forced seals. This means that when the valve is closed, the gate must be pushed towards the valve seat by an external force to ensure the sealing surface is sealed.
Motion pattern: Wedge gate gate moves linearly with the spindle, also known as Os&Y gate. There are usually trapezoidal threads on the lifting rod, which convert the rotary movement into straight movement through the nuts on the top of the valve and the guide groove in the valve body, that is, they convert the operating torque into operating thrust. When the gate valve is opened, the liquid channel is completely free if the gate lifting height corresponds 1:1 to the valve size. However, this position cannot be monitored during operation. In actual use, it is identified by the apex of the spindle, the position in which it does not move, as its fully open position. To compensate for the blocking phenomenon due to temperature changes, it is generally opened to the apex position and then returned to 1/2-1 circle as the fully open valve position. Therefore, the fully open position of the wedge gate is determined by the position of the gate (i.e. the stroke). Some spool valves have stem nuts mounted on the spool, and turning the handwheel turns the stem, lifting the spool. This wedge gate valve is called rotating shaft wedge gate valve or non-rising shaft wedge gate valve.
Wedge slider – advantages and disadvantages
Advantages of the gate valve
- Flow resistance is low. The inner media channel of the wedge valve body is straight, the media flows straight, and the flow resistance is low.
- Less effort required when opening and closing. Compared with the shut-off valve, the movement direction of the slide is perpendicular to the flow direction of the medium, as it is independent of whether it is open or closed.
- High altitude, long opening and closing time. The opening and closing stroke of the gate is large and lifting is done by the screw.
- The water hammer phenomenon is not so easy to create with wedge valves. The reason for this is the long shutdown time.
- The medium can flow in any direction on both sides of the wedge gate, easy to install. Both sides of the sliding channel are symmetrical.
- The overall length of the wedge slide is small.
- Simple shape, short length, easy to manufacture and wide range of applications.
- The structure is compact, the wedge valve has good rigidity, the channel is smooth, the flow resistance is small, the sealing surface is made of stainless steel and hard alloy, and the service life is long. Using a PTFE seal is reliable and easy to use.
Disadvantages of the gate valve
- Erosion and scratches occur easily between sealing surfaces and maintenance is difficult. Large size, requires some space to open, a long time to open and close. The structure of the wedge gate valve is more complicated.
NTGD valve is professional wedge gate valve manufacturer If you have any questions, please feel free to contact us
Everything you need to know about gate valves
Everything you need to know about gate valves
