When the gate valve is closed, the sealing face can only be sealed by material pressure, that is, the sealing face of the gate can only be pressed to the seat on the other side by material pressure to ensure the sealing face, that is, self-sealing.Most GATE VALVES ARE FORCE-SEALED, THAT IS, WHEN THE valve is closed, the gate should be forced against the seat with the help of an external force to ensure the sealing performance of the sealing surface.
Movement mode: the gate valve and the seat of the straight line movement, also known as the rod gate valve. Usually, elevator rods have trapezoidal threads. According to the Nut at the top of the valve and the guide grooves in the body, the rotational motion becomes straight, that is, the operating torque becomes the operating thrust.When the valve is opened and the lift height of the gate is equal to 1:1 times the diameter of the valve, the flow passage is completely clear, but it is difficult to monitor during operation. In practice, the end of the seat should be marked, that is, the position that cannot be opened as the full open position. In order to account for the locking phenomenon of temperature changes, it is usually adjusted to the end position and then RE wound 1/2-1 turn as the full open valve position. Therefore, the fully open position of the valve should be determined according to the gate position (i.e., stroke) >. Some gate valve nuts are set on the gate and the hand wheel rotates to push the SEAT around and then raise the gate. These valves are called rotary stem gate valves or dark stem gate valves.
The opening and closing part of the gate valve is the gate plate. The direction of motion of the ram is perpendicular to the direction of the liquid. Gate valve can only be fully opened and closed, can not be adjusted and throttled. The ram has two sealing faces. The common method is the two sealing surface of the gate valve to produce a groove, the groove Angle varies with the valve parameters, generally 5°, when the material temperature is not high will be 2° .
The gate plate of the wedge gate valve can be made into a whole, called the stiffness gate; Can also be made into a small amount of deformation of the gate, improve its manufacture ability, fill in the sealing surface Angle of view in the production of errors. This type of gate is called an elastic gate. When the gate valve is closed, the sealing face can only be sealed by material pressure, that is, the sealing face of the gate plate is pressed to the seat on the other side by material pressure to ensure the sealing face, that is, self-sealing. Most GATE VALVES ARE FORCE-SEALED, THAT IS, WHEN THE VALVE IS CLOSED, THE GATE IS pressed AGAINST THE SEAT WITH the help OF AN external force TO ensure the sealing performance of the sealing face. The gate valve gate plate moves in a straight line with the seat, which is called the lift rod gate valve, also known as the open rod gate valve.