Under what circumstances with the butterfly valve, under what circumstances with the ball valve?
The flow control accuracy requirements are not high, the fluid pressure is small place with butterfly valve, butterfly valve is the simplest kind of valve, mainly used in regulating the air flow and powder flow!According to the pressure of the liquid and gas fluid control, flow effect, rapid opening and can completely cut off for flow with the ball!
Selection principle of ball valve:1, oil, natural gas transmission mains, need to clean the pipeline, and be buried in the ground, all pass by, the ball valve full welded structure; buried in the ground, select all pass through ball valve welded connection or flange connection; pipe flange connection, welding, selection of connection, all pass through or shrink the diameter of the ball valve.2, product oil pipeline and storage equipment, choose flange connected ball valve.3, the city gas and natural gas pipeline, choose flange connection and internal thread of the floating ball valve.1 、 in the oxygen piping system of the metallurgical system, the fixed ball ball valve should be selected after the strict degreasing treatment and the flange connection.2, low temperature medium piping system and device, should choose to use the valve cover of low temperature ball valve.3 、 the lifting rod type ball valve can be used on the pipeline system of the catalytic cracking unit of the oil refining unit.4, chemical systems such as acid and alkali corrosive media and piping systems, it is appropriate to choose austenitic stainless steel, PTFE seat sealing ring for all stainless steel ball valve.5 、 metal to metal sealing ball valve can be used in metallurgy system, power system, petrochemical equipment, piping system or device of high temperature medium in city heating system. 6, the need for flow regulation, you can choose the worm gear drive, pneumatic or electric with V shaped opening of the regulating valve.
Butterfly valve for occasions:Butterfly valve is suitable for flow regulation. Due to the pressure loss of the butterfly valve in the pipe is relatively large, is about three times the gate, so the choice of valve, the piping system should fully consider the influence of the pressure loss should also be considered robust when closing the butterfly plate to withstand the pressure medium pipeline. In addition, the operating temperature limit of resilient seat materials must be taken into account at elevated temperatures.Butterfly valve structure length and overall height is small, open and close speed is fast, and has good fluid control characteristics, butterfly valve structure principle is most suitable for making big mouth valve. When the butterfly valve is used as a control flow, the most important thing is to choose the size and type of butterfly valve so that it can work properly and effectively.Usually, in throttling, adjusting control and slurry medium, the structure length is short and the opening and closing speed is fast (1/4 rpm). Low pressure cut-off (small pressure), butterfly valve is recommended.Butterfly valves can be used in double adjustment, necking channels, low noise, cavitation and gasification, with little leakage to the atmosphere and corrosive media.
