The sealing performance is worse than that of ball valves and globe valves

Gate valve: A gate valve is a valve whose closing member (gate) moves along the vertical direction of the channel axis. The sealing performance is worse than that of ball valves and globe valves, so it is used in places where the sealing requirements are not very high. The ball valve is mainly used for cutting off, distributing and changing the flow direction of the medium in the pipeline. Ball valve: It evolved from a plug valve. Disadvantages: The flow adjustment range is not large.. It can be suitable for low temperature and high pressure as well as high temperature and high pressure, and can be used for casting different materials of valves. When the opening reaches 30%, the flow will enter more than 95%. The ball is rotated 90° around the axis of the valve stem to achieve the purpose of opening and closing. 

Butterfly valve: The butterfly valve is a valve that PTFE coated fiberglass fabric uses a disc-type opening and closing member to reciprocate 90° to open, close and adjust the fluid channel. The ball valve designed as a V-shaped opening also has a good flow adjustment function. It can be applied to the two-way opening and closing and adjustment of ventilation and dust removal pipelines, and is widely used in gas pipelines and waterways in metallurgy, light industry, electric power, and petrochemical systems. ②Due to the limitation of the structure of the butterfly valve and the sealing material, it is not suitable to be used in the high temperature and high pressure pipeline system. 

Generally, the gate valve cannot be used as an adjustment flow. Its opening and closing part is a ball. However, gate valves are generally not used in pipelines that transport mud and other media. Disadvantages: ①The overall size and opening height are large, and the space required for installation is also large; ②In the opening and closing process, the sealing surface is relatively rubbed, and the wear is large, and it is easy to cause abrasion even at high temperature; ③General gate valve There are two sealing surfaces, which add some difficulties to processing, grinding and maintenance; ④Long opening and closing time. The general working temperature is below 300℃ and below PN40. 

Advantages: Simple structure, small size, light weight, saving consumables, and can be used in large-diameter valves; Quick opening and closing, low flow resistance; t can be used in media with suspended solid particles, and can also be used in powder according to the strength of the sealing surface And granular media. It is mainly used for cutting off the medium in the pipeline, that is, fully open or fully closed. Advantages:  small fluid resistance; small torque required for opening and closing;can be used in the ring network pipeline where the medium flows in both directions, that is to say, the flow direction of the medium is not restricted; When fully opened, the sealing surface is affected by the work The erosion of the medium is smaller than that of the shut-off valve;The body structure is relatively simple, and the manufacturing process is better;The structure length is relatively short