... 3. Small torque Pneumatic control valve regulating butterfly valve ♦ Pneumatic control valve regulating butterfly valve, the valve disc and seal ring adopt ... water industries in water, sewage, oil liquid, air, gas, natural gas andwater vapor, and other media to cut-off or adjust flow control ... . 1) On-off type: Match with 2/5way solenoid valve, 2/3way solenoid valve realize switch control; ...