The trench type fire fighting signal gate valve is a type of opening and closing gate. The direction of movement of the gate is perpendicular to the direction of the fluid.Gate valves can only be fully open and fully closed, and cannot be adjusted or throttled. The gate valve is sealed by the contact between the valve seat and the gate plate. Usually, metal materials are deposited onto sealing surfaces to increase wear resistance, such as 1Cr13. STL6. stainless steel. Rams have both rigid and elastic types. According to the different types of gates, gate valves are divided into rigid gate valves and elastic gate valves.
Working principle of groove type fire fighting signal gate valve:
The gate of the groove type fire fighting signal gate valve has two sealing surfaces. The two sealing surfaces of the commonly used gate valve form a wedge shape. The wedge angle varies depending on the valve parameters, usually 5 ¡ã, and when the medium temperature is not high, it is 2 ¡ã 52 ¡ã. The gate plate of a wedge gate valve can be made into a whole, called a rigid gate plate; It can also be made into a gate that can produce slight deformation to improve its process performance and compensate for the deviation of sealing surface angle during the processing. This type of gate is called an elastic gate. When the gate valve is closed, the sealing surface can only be sealed by the medium pressure, that is, the sealing surface of the gate can be pressed to the valve seat on the other side by the medium pressure, ensuring the sealing surface is self sealed. Most gate valves are forcibly sealed, meaning that when the valve is closed, the gate should rely on external force to forcefully press against the valve seat to ensure the sealing of the sealing surface. The gate plate and valve stem of a gate valve move in a straight line together, which is called a rising stem gate valve, also known as a rising stem gate valve. Usually, there is a trapezoidal thread on the lifting rod, which converts the rotational motion into linear motion through the nut at the top of the valve and the guide groove on the valve body, that is, the operating torque becomes the operating thrust. When the valve is opened and the lifting height of the gate is 1:1 times the diameter of the valve, the fluid passage is completely unobstructed, but this position cannot be monitored during operation. In practical use, the vertex of the valve stem serves as a marker, and the position that cannot be moved is considered its fully open position. To consider the locking phenomenon of temperature changes, it is usually done by opening to the top position and then reversing 1/2-1 turn as the fully open valve position. Therefore, the fully open position of the valve is determined based on the position of the gate. Some gate valves have a stem nut installed on the gate, and the hand wheel rotates to drive the stem to rotate and lift the gate. This type of valve is called a rotary stem gate valve, or a non rising stem gate valve.
What are the precautions for groove type fire fighting signal gate valves
1)Hand wheels, handles, and transmission mechanisms are not allowed to be lifted and collisions are strictly prohibited.
2)Double gate valves should be installed vertically (i.e. the valve stem is in a vertical position and the hand wheel is at the top).
3)Before opening a gate valve with a bypass valve, the bypass valve should be opened to balance the inlet and outlet pressure difference and reduce the opening force.
4)Install the gate valve with transmission mechanism according to the product manual.
5)If the valve is frequently opened and closed, lubricate it at least once a month.
6)Gate valves are only used for fully open and fully closed operation of various pipelines or equipment media, and throttling is not allowed.
Gate valves with hand wheels or handles should not have auxiliary levers added during operation (if the sealing is not strict, the sealing surface or other components should be inspected and repaired). Turn the hand wheel handle clockwise to close, otherwise it will open. Gate valves with transmission mechanisms should be used according to the product manual. |
