Working principle and classification of the stop valve

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The shut-off valve, also called the door, is the most widely used type of valve. It is popular because of the small friction between the sealing surfaces during the opening and closing process. It is relatively durable, the opening height is not large, and the manufacturing is easy. Convenient, not only for medium and low pressure, but also for high pressure.

The closing principle of the shut-off valve is that, relying on the pressure of the valve bar, the sealing surface of the valve disc and the sealing surface of the valve seat are closely fitted to prevent the medium from flowing.

The shut-off valve allows only one-way flow of the medium and is directional when installed. The structural length of the shut-off valve is larger than that of the gate valve, and the fluid resistance is large. When the machine is operated for a long time, the sealing reliability is not strong.

The classification of the globe valves is:

1) General-purpose globe valve

2) Flow-type stop valve: In the DC or Y-shaped stop valve, the flow path of the valve body is inclined with the main flow path, so that the degree of damage of the flow state is smaller than that of the conventional stop valve, and thus the pressure loss through the valve is correspondingly Small.

3) Type stop valve: In the angle cut-off valve, the fluid only needs to change the primary direction so that the pressure drop through the valve is smaller than that of the conventional structure.

4) Plug stop valve: This type of shut-off valve is a variant of a conventional shut-off valve. In this valve, the flap and seat are usually designed based on the principle of the plunger. The valve flap is polished into a plunger that is coupled to the valve stem, and the seal is achieved by two elastomeric sealing rings that are placed over the plunger. The two elastomeric seals are separated by a collar and the seal around the plunger is pressed by the load exerted by the bonnet nut on the bonnet. The elastomeric seal can be replaced and can be made from a wide variety of materials. The valve is mainly used for "opening" or "off", but with a special form of plunger or special collar, it can also be used to regulate flow. .