... cut off or failure (Explosion-prool offer available) Single-control solenoid valve: Valve opens or closes when power on , vice ... versa(explosion-proof offer available) Double-control solenoid valve: Valve opens when one coil is power-on. ... ,(2) Single-Acting ,(3) Model2). Solenoid Valve, (1) Single-Control Solenoid Valve ,(2) Double-Control Solenoid Valve ,(3) Voltage ,(4) Explosion-Proof ...