Please tell me the types and uses of valves.

1. Gate valve, also called gate valve, is a widely used valve. Its closing principle is that the gate sealing surface and the valve seat sealing surface are highly smooth, flat and consistent, and fit together to prevent the flow of media, and rely on the mold shape of the top mold, spring or gate plate to enhance the sealing effect. It mainly plays a cutting role in the pipeline.

2. Globe valve, also called cut-off valve, is the most widely used valve. The reason why it is so popular is that the friction between the sealing surfaces during the opening and closing process is small and it is relatively durable. The opening height is small, easy to manufacture and easy to maintain. It is not only suitable for medium and low pressure, but also for high pressure.

3. Butterfly valve, also called butterfly valve, as the name suggests, its key components are like butterflies facing the wind and rotating freely. The disc of the butterfly valve is a disc that rotates around an axis in the valve seat. The size of the rotation angle is the opening and closing degree of the valve.

4. The working principle of the ball valve is to make the valve unobstructed or blocked by rotating the valve. Ball valves are light on and off, small in size, can be made into large diameters, have reliable sealing, simple structure, and easy maintenance. The sealing surface and spherical surface are always in a closed state and are not easily eroded by the medium. They are widely used in various industries.

5. The plug valve relies on the plug body to rotate around the center line of the valve body to achieve the purpose of opening and closing. Its function is to cut off, divide the field and change the flow direction of the medium. It has a simple structure and small dimensions. It only needs to be rotated 90 degrees during operation, and the fluid resistance is not large. Its disadvantages are that the switch is laborious, the sealing surface is easy to wear, and it is easy to get stuck at high temperatures, so it is not suitable for regulating flow.

6. The check valve is a valve that automatically opens and closes by the force of the fluid itself. Its function is to prevent the medium from flowing back. It has many names, such as check valve, one-way valve, one-way valve, etc. It can be divided into two categories according to structure.

7. The pressure reducing valve is an automatic valve that reduces the medium pressure to a certain value. Generally, the pressure behind the valve is less than 50% of the pressure in front of the valve. There are many types of pressure reducing valves, mainly including piston type and spring diaphragm type.

8. Drain valve, also called steam trap drain valve, steam water valve, drain trap, return water box, return water door, etc. Its function is to automatically discharge the continuously generated condensation water without letting the steam come out. There are many types of traps, including float type, float type, bell float type, pulse type, thermodynamic type, and thermal expansion type. Commonly used ones are float type, bell float type and thermodynamic type.