Valve Working principle
- Aug 28, 2017 -
Gate Valve headstock is the gate, the movement direction of the gate and the direction of the fluid, the gate valve can only be open and full off, can not be adjusted and throttling. The gate has two sealing surfaces, the most commonly used mode gate valve two seals form the wedge shape, the wedge angle with the valve parameter and the different, usually is 5 °, the medium temperature is not high when 2°52 '. The wedge-type gate valve can be made into a whole, called a rigid gate plate, can also be made to produce micro-deformation of the brake board to improve its process, to make up for the sealing surface angle in the process of the deviation generated, this kind of gate is called the Elastic Gate plate. When the gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, depending on the medium pressure to press the sealing surface of the brake plate to the other side of the valve seat to ensure sealing surface, this is the self sealing. Most of the gate valves are forced seal, that is, when the valve is closed, it is necessary to force the gate to be pressed to the seat by external forces to ensure sealing of the seal surface. Gate valve board with the valve stem for a straight line movement, called the lifting rod gate valve, also known as the Ming rod gate valve. Usually, there is a trapezoidal thread on the lifter, through the nut on the top of the valve and the guide groove on the valve body, turning the rotation movement into a straight line motion, that is, turning the operation torque into operational thrust. When opening the valve, when the gate lifting height is equal to the valve diameter of 1:1 time times, the flow of the channel is fully unblocked, but at run time, this location is not monitored. In actual use, it is the vertex of the stem as a sign, that is, the position of the open, as its full opening position. In order to consider the phenomenon of temperature change deadlock, usually in the vertex position, and then pour back to the 1/2-1 circle, as the position of open valve. Therefore, the full open position of the valve, according to the position of the gate is the trip to determine. Some gate valve, the stem nut is located on the brake board, the handwheel rotates to drive the stem to rotate, and makes the gate ascend, this kind of valve is called the revolving rod gate valve, or is called the Dark pole gate valve.