Flanged butterfly valve gate flow and switch

Flange butterfly valve flow and the relationship between the switch of the door, and basically a linear scale change. If is used to control the flow, the flow characteristic and pipe flow resistance have close relationship, such as two piping valve gate diameter, forms, etc. All the same, and the pipe loss coefficient is different, the valve gate flow will be a big difference. If the flange butterfly valve door in state of throttling range is larger, the valve plate on the back of the easy cavitation occurs, the possibility of damage to the valve gate, in general more than 15 & deg; External use. Flange butterfly valve in the opening in the door, the valve body and disc front of mouth shape to the valve shaft as the center, on both sides of the form a complete different state, the butterfly plate on one side of the front end of downstream water direction, the other side of the upstream water direction, therefore, on one side of the valve body and valve plate form like opening nozzle shape, on the other side is similar to throttle aperture openings, nozzle side of more quickly than the throttling velocities, and produce negative pressure under the side of the throttle valve door, often there will be a rubber seal off. Door flange butterfly valve, operating torque due to the opening door opening and closing of the valve in a different direction and the value of each different, horizontal pneumatic butterfly valve gate, especially large diameter valves, due to the depth of the water, the valve shaft, the water head difference generated by the torque also nots allow to ignore, general large diameter pneumatic butterfly valve gate needs to be installed into pneumatic butterfly valve gate, pneumatic butterfly valve door switch quickly, with large output torque, etc. In addition, the valve inlet side door device elbow, form the bias current, torque will be increased. Valve opening of the door in the middle, because the water flow of torque, operators need to be self-locked.