PVC Pneumatic Butterfly Valve Spring Return Type is single acting pneumatic valve, the valve is setted by normal close or normal open position, if the air supply unavailable the valve will be closed or open at the setted postion to protect the system safety. the spring type actuator output torque is samller than double acting type, for same valve it require the single acting actuator large model than double acting actuator. Ningbo RMI Plastic Co.,Ltd offer PVC Pneumatic Butterfly Valve single acting with following specification and featurers Specification: Size: DN50~DN400 (2 inch ~ 16 inch) Connection: Wafer, Lug Material: PVC Actuator: Pneumatic Type: Spring return Air supply: 4-6bar Other valves available: CPVC pneumatic butterfly valve, PPH pneumatic butterfly valve, PVDF pneumatic butterfly valve Featurers Different materials of butterfly valve for optional. Spring return…