5. The maximum number of turns of the valve stem nut must be stated when selecting the multi turn valve electric device, so that the relevant gear speed ratio of the position indicating mechanism in the electric device can be correctly selected, so that the position indication has enough precision to meet the observation of the valve opening and closing degree during the valve operation, otherwise it is easy to cause illusion, Affects normal operation.

Pneumatic rubber lined butterfly valve, with flange, clamp, sealing lining of nitrile rubber, ethylene propylene rubber, heat-resistant ethylene propylene rubber, natural rubber, neoprene rubber, fluororubber, polytetrafluoroethylene, can be selected more reasonably according to the chemical properties of the medium.