Gate valve, butterfly valve, ball valve advantages and disadvantages? What are the usual valves?
Commonly used valves are: gate valve, globe valve, check valve, ball valve, butterfly valve, safety valve, regulating valve, plug valve and so onValve: valve is closed parts (RAM) vertical movement of the valve in the pipeline along the channel axis, used primarily as a medium cut that open and close use. In general, the valve can not be used as a regulation flow. The utility model can be applied to low temperature pressure, and can also be applied to high temperature and high pressure, and can be made according to different materials of the valve. But the valve is generally not used to transport mud and other media pipeline.Advantages: fluid resistance is small; the opening and closing torque needed by the smaller; can use the ring pipe flow to the two direction in the medium, that is to say the unrestricted flow of medium; the fully open, the sealing surface by the erosion of the working medium is smaller than the cut-off valve; the body has the advantages of simple structure, manufacturing good craft; the structure of relatively short length.Disadvantages: the size and height on the larger required installation space is larger; in the process of opening and closing, a relative friction sealing, friction is large, even scratch phenomenon caused by easily at high temperature; the valve has two sealing surface, to processing, polishing and maintenance of some increase the opening and closing time difficult.
Stop valve: a valve that closes the valve and moves along the center line of the valve seat. According to this form of valve movement, the valve seat opening change is proportional to the valve stroke. Because of the valve stem to open or close the trip is relatively short, but very reliable cut off function, and because changes in the valve seat and the valve stroke is proportional, is very suitable for flow regulation. Therefore, this type of valve is very cooperative for cutting or regulating and throttling.Advantages: in the process of opening and closing, because the friction between the valve and the sealing surface of the valve body is smaller than that of the gate valve, the utility model has the advantages of wear resistance. Second, the opening height is generally only 1/4 of the seat channel; therefore, it is much smaller than the gate valve; usually there is only one sealing surface on the valve body and the disc; therefore, the manufacturing process is better and the service is easy to maintain. Because its packing is generally a mixture of asbestos and graphite, it has a higher temperature resistance. Steam valves are normally used with stop valves.Disadvantages: as a result of the medium through the valve flow direction has changed, so the minimum flow resistance valve is higher than most other types of valves; second, due to longer travel, opening slower than the ball.
Steam traps: in steam, compressed air and other media, there will be some condensation water formation, in order to ensure the efficiency and safety of the device operation, should be timely discharge of these useless and harmful to the media, to ensure the consumption and use of the device. It has the following functions: 1. It can quickly eliminate the condensed water; prevent leakage of steam; remove air and other non condensable gases.Pressure reducing valve: by adjusting the inlet pressure to a certain outlet pressure, and rely on the energy of the medium itself, so that the outlet pressure automatically maintain a stable valve.Check valve: also known as reverse flow valve, check valve, back pressure valve and one-way valve. The valves are automatically driven and closed by the flow of the medium itself, belonging to an automatic valve. The check valve is used for piping system, the main function is to prevent the backflow of medium, prevent the reverse of pump and drive motor, and release the container medium. The check valve can also be used to provide a supply to the auxiliary system where the pressure may rise above the system pressure. It can be divided into swing type (rotating by gravity center) and lifting type (moving along the axis).
