The opening and closing component of the protective hidden stem gate valve is the gate, and the movement direction of the gate is perpendicular to the fluid direction, which can be adjusted and throttled. The gate valve has two sealing surfaces, and the two sealing surfaces of the commonly used mode gate valve form a wedge shape. The wedge angle varies with the valve parameters, usually 50, and 2 ° 52 '' 'when the medium temperature is not high. The gate of a wedge gate valve can be made as a whole, called a rigid gate; It can also be made into a gate that can produce slight deformation to change its processability and compensate for the deviation of the sealing surface angle during the processing. This type of gate is called an elastic gate.

General requirements for protecting concealed stem gate valves:

1. The specifications and categories of protective concealed stem gate valves should comply with the requirements of the pipeline design documents.

2. The model of the protective concealed stem gate valve should indicate the national standard number requirements it is based on. If it is an enterprise standard, the relevant description of the model should be indicated.

3. The working pressure of the protective hidden stem gate valve should be ≥ the working pressure of the pipeline. On the premise of not affecting the price, the working pressure that the valve can withstand should be greater than the actual working pressure of the pipeline; Either side of the elastic seat sealed gate valve should be able to withstand 1.1 times the valve working pressure value without leakage when it is closed; When the valve is open, the valve body should be able to withstand twice the working pressure of the valve.