What are the commonly used valves for gas distribution?
- Safety valve: A safety valve is a safety protection valve. Its opening and closing parts are normally closed under external force. When the pressure of the medium in the equipment or pipeline rises, it will automatically open when it exceeds the specified value. The pressure of the medium in the pipeline or equipment exceeds the specified value. It is mainly used on boilers, pressure vessels and pipelines. The control pressure does not exceed the specified value, which plays an important role in protecting human safety and equipment operation.
- Shut-off valve: The shut-off valve is mainly used for cutting off in the pipeline. It has the advantages of good manufacturing process, easy maintenance, small opening height, etc., and usually has only one sealing surface, which has less friction than the gate valve. It is widely used, but due to the large opening and closing torque and the long structure length, generally the nominal diameter is limited to DN≤200mm, and the fluid resistance loss is large. This limits the wider use of globe valves.
- Ball valve: The ball of the ball valve rotates around the center line of the valve body to achieve the opening and closing functions. It is mainly used to cut, distribute and change the flow direction of the medium in the pipeline. It is a new type of valve widely used in recent years. At present, the sealing material of the ball valve is widely used in plastics, and has good sealing performance, and has been widely used in vacuum systems.
- Butterfly valve: The opening and closing part of the butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve the opening and closing or adjusting function. Butterfly valve fully open to fully closed is usually less than 900, and it is not self-locking with the butterfly stem itself. In order to locate the butterfly plate, a worm reducer must be installed on the valve stem.
- gate: Gate valve is one of the commonly used shut-off valves. It is mainly used to connect or cut off the medium in the pipeline. It is suitable for a wide range of pressure, temperature and caliber, especially for medium and large caliber pipes.
- Check valve: Check valve refers to the valve that automatically opens and closes the valve flap based on the flow of the medium itself. It is used to prevent the medium from flowing backward. According to its structure, it can be divided into two types: lift and swing.
- Regulating valve: The control valve is divided into nine types: single seat type, double seat type, sleeve type, angle type, three way type, diaphragm valve, butterfly valve, ball valve and eccentric rotary valve. The first six are straight strokes and the last three are angular strokes. These nine control valve products are also the most basic products, also known as ordinary products, basic products or standard products. A variety of special products and special products are improved based on these nine types of products.
- Needle valve: The spool of a needle valve is a very sharp cone, which is inserted into the valve seat like a needle.It can withstand greater pressure than other types of valves and has a good sealing performance, so it is generally used for smaller flows and higher pressures. The seal of the gas or liquid medium is often used in conjunction with the pressure gauge.
- The electromagnetic valve: The solenoid valve is divided into three categories in principle (ie: direct-acting, step-by-step pilot-operated), and the valve disc structure and material are divided into six sub-categories (direct-acting) (Diaphragm structure, stepped rewinding structure, pilot film structure, direct acting piston structure, stepped direct acting piston structure, pilot piston structure).
- Stopcock: The plug valve is a valve that uses a plug body with a through hole as the opening and closing member. The valve can be opened and closed by the rotation of the plug body and the valve stem. The valve has a simple structure, rapid opening and closing, and low fluid resistance. One of the valves has not been replaced by ball valves and other types of valves in recent years, but the market is becoming more and more popular.
Valves commonly used in gas transmission and distribution are: safety valve, globe valve, ball valve, butterfly valve, gate valve, check valve, regulating valve, solenoid valve, plug valve, needle valve, etc.