Solenoid valve is a basic component in automatic flow control,it is actuator but not limitedto hydraulic,pneumatic.

solenoid valve is mainly used to control the direction of hydraulicflow,machines in plant are usually controled by hydraulic cylinder and thus the solenoidvalve is applyed.generally,solenoid valve manufacturers in China not only producehydraulic solenoid valve,they mainly manufacturer hydraulic-pneumatic combined two waysolenoid valve.

The main working theory of solenoid valve is that there is a fully closed cabinet insidethe solenoid valve,with holes in different position.each hole is connected with differenthose.the valve is centered with two electric magnets aside,when the power is on,the valvewill be pulled to that side.though the movement of the valve,the hole which is connectedto the hose will be closed /open,the oil inlet is always open,the hydraulic oil flowsto different hoses and push the cylinder piston by its pressure,the piston drives the pistonstem and then the equipment into movement,by this means,the mechanical movement can becontroled by controling the electricity of solenoid valve.