big size gate valve For sale
How much do you know about the closing and opening of the big size gate valve For sale? Let’s take a look at it briefly below!
1. When the big size gate valve For sale is closed
The sealing surface can be sealed only by the medium pressure, that is, relying on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves are forced to seal, that is, when the valve is closed, the gate must be forced against the valve seat by external force to ensure the tightness of the sealing surface. The gate of the gate valve moves linearly with the valve stem, which is called a lift-rod gate valve (also called an open-rod gate valve). Usually, there are trapezoidal threads on the lift rod. Through the nut at the top of the valve and the guide groove on the valve body, the rotary motion is changed into a linear motion, that is, the operating torque is changed into the operating thrust.
2. When the big size gate valve For sale is open
When the lift height of the gate is equal to 1:1 times the diameter of the valve, the passage of the fluid is completely unblocked, but this position cannot be viewed during operation. In actual use, the apex of the valve stem is used as a sign, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon caused by temperature changes, it is usually opened to the top position, and then back to 1/2-1 turn, as the position of the fully open valve. Therefore, the fully open position of the valve is determined according to the position of the gate (ie stroke).