How to choose the finest valve?

1. Gate valve:
The gate valve is used as a cut-off medium. When it is fully open, the entire flow is through. At this time, the pressure loss of the medium is minimized. Gate valves are generally suitable for applications that do not require frequent opening and closing and that keep the gate fully open or fully closed. Not suitable for use as an adjustment or throttling. For high-speed flowing media, the gate can cause vibration of the gate in a partially opened condition, and the vibration may damage the sealing surface of the gate and the valve seat, and the throttling will cause the gate to suffer erosion of the medium. From the structural form, the main difference is the form of the sealing element used. According to the form of the sealing element, the gate valve is often divided into several different types, such as: wedge gate valve, parallel gate valve, parallel double gate gate valve, wedge type double brake gate gate and so on. The most common forms are wedge gate valves and parallel gate valves.

2. Globe valve:
The valve stem axis is perpendicular to the valve seat sealing surface. The valve stem has a relatively short opening or closing stroke and a very reliable cutting action, making this valve very suitable as a medium for cutting or adjusting and throttling. When the valve of the stop valve is in the open state, the contact between the valve seat and the sealing surface of the valve no longer comes into contact with it, and it has a very reliable cutting action. This valve is very suitable for the cutting or adjusting of the medium and the section. Streaming use.
Once the shutoff valve is in the open state, there is no more contact between its seat and the sealing surface of the disc, so its mechanical seal wear is less, because most of the seat and disc of the cutoff valve are easier to repair or replace. It is not necessary to remove the entire valve from the pipeline when sealing the components. This is suitable for the welding of valves and pipelines. The direction of flow of medium through such valves has changed, so the flow resistance of the shut-off valve is higher than other valves.

Commonly used stop valves are the following:
1) Angle-type shut-off valve; In the angle-type shut-off valve, the fluid only needs to change the direction once, so that the pressure drop through this valve is smaller than that of the conventional structure.
2) DC type stop valve; In the direct or Y type globe valve, the flow channel of the valve body is in a diagonal line with the main flow channel, so the damage degree of the flow state is smaller than the conventional stop valve, so the pressure loss through the valve is also corresponding. It's small.
3) Piston stop valve: This type of globe valve is a variant of a conventional globe valve. In this valve, the flap and seat are usually designed based on the plunger principle. The valve flap is ground to connect the plunger to the valve stem, and the seal is achieved by two elastic seals that are placed on the plunger. The two elastomeric seals are separated by a collar and the seal around the plunger is secured by the load applied by the bonnet nut to the valve cap. Elastic seals can be replaced and can be made from a wide variety of materials. This valve is mainly used for "open" or "closed", but it is equipped with a special type of plunger or special collar, which can also be used to regulate the flow .