The valve consists of two main valve and pilot valve components. For temperature lower than 80 ℃, air, gas, oxygen and other gas pipeline. Use rotation adjustment screw, top enlighten the valve plate, the medium from the valve before the valve through the guide catheter into the main valve cover chamber, prompting media pressure push the piston, so that the main valve disk open, medium flow valve, while pressure from the valve into the pilot valve directly below the pass, and acting on the diaphragm and the diaphragm above the pressure to maintain the best balance to achieve the purpose of decompression.