Solenoid valve is a automatic valve and can controlled by pressure controller，tempera ture controller and manual switcher．In air conditioning and refrigerating equipment，it usually use as remot control stop valve，adjusting actor or safety protector． ZDF model suit mr steam system．RDF model suit for fuel system．GDF model is high pressure system．　

　　These models valve are pilot valve．It consist shell，coil，piston，spring，valve body，seal ring etc．When cut on，coil cause magnet and pickup plug，small orifice open,upside or piston connected with valve output，so reduced the pressure in upside of plston, then the pressure dlnerence both side of piston happen，it lead piston move upward， hereso，the valve open．When open the main valve；piston will keep this station even if the pressure difference exist because of flow inertia function．When cut off，plug return under weight force and spring fOrce then the small orifice close．Media flow to upside of piston，so balance pressure both side of piston．The piston return to close the main valve．

The valve must install in horizontal pipe line under vertical position．
The flow direction must be meet the arrow direction in valve body．
Installing position should be low viberatlon．
Must install filter before solenoid valve in order to prevent block throttle port and lead to no function．
The coil input power must meet rated input power showed on the label．
Departure coil from valve when energized in coil is limited in order to avoid damage the coil．