Butterfly knowledge discussed in the application process
1930s, the United States invented the butterfly valve, the 1950s introduced to Japan, the 1960s was widely used in Japan, while in China it is a matter of promotion after the 1970s. The world in general DN300 mm butterfly valve has gradually replaced the valve. Valve and valve opening and closing time is short compared to the operating torque, small installation space and light weight. To DN1000, for example, butterfly about 2T, while the gate of about 3.5T, and the valve is easy with a variety of drive combinations, with good durability and reliability. API flange type globe valve
When the rubber seal butterfly valves for throttling drawback is that, due to improper use will produce cavitation, the rubber seat spalling, damage from happening. To this end, the international community has now developed metal sealing butterfly valve, cavitation area decreases, in recent years, China has also developed a metal sealing butterfly valve, in Japan in recent years has also developed resistance to cavitation, low vibration, low noise comb butterfly. general sealing seat of life under normal circumstances, the rubber 15 Year - 20 years, 80 years of metal - 90 years. But how correct choice they should according to working conditions. Butterfly valve opening and the relationship between the flow essentially linearly proportional to the change. If used to control the flow, the flow resistance of the flow characteristics and piping is also closely related, such as the installation of two pipelines valve size, form, etc. identical, and the pipe loss coefficient is different, the difference between the flow valves will be great. Non rising stem resilient seated gate valve
If a significant reduction in the state of the throttle valve, the valve plate on the back prone to cavitation, there is the possibility of damage to the valve, generally used in the 15 ° outside. When the valve is in the opening, the opening shape of the front end of the body and disc formed with the valve shaft as the center, formed on both sides to complete the different states, the disc along the flow direction of the front side of the move, the other side of the water countercurrent direction move, therefore, the side of the valve body and the valve plate is formed like a nozzle-shaped openings, similar to the other side of the orifice-shaped openings, fast nozzle orifice side than the side of the flow rate, and the throttle valve will produce the following negative side, often there will be rubber seals off. Wafer type butterfly valve
Valve operating torque, due to open and close the valve opening and its value varies in different directions, horizontal butterfly valve, especially the large-diameter valve, due to the water depth, valve shaft, the torque generated by the water head difference can not be ignored. Further, when the inlet side of the valve means bend to form a bias current, torque will be increased. When the valve opening in the middle, because the water flow torque acts, the operating mechanism requires self-locking. http://www.tjlvalve.com/
