Abstract: A deionized water supplying system is connected to a deionized water supply tank, a deionized water supply pipe and a deionized water circulating pipe. The system includes a three-ported valve having a first port connected to the deionized water supply pipe via a first branch pipe, a second port connected to the first port when the three-ported valve is in a first state, and a third port connected to the deionized water circulating pipe via a second branch pipe and communicating with the first port when the three-ported valve is in a second state.

Abstract: A pneumatically-operated water control valve includes an air actuator, a valve control portion, and an intermediate cylinder block mounted between the air actuator and the valve control portion. The intermediate cylinder block has a first bellows, a second bellows and an intermediate shaft which are placed so as to form a closed space. The intermediate shaft is serially connected between a piston shaft of the actuator and a valve shaft of the valve control portion. The closed space separates the piston shaft from the valve control portion.