Pressure control valve, using gas pressure to the main valve to change the flow of gas leaving the movement. Press control mode is divided into different pressure control, differential pressure control and relief control three. Pressure control

means that the control signal applied pressure is gradually rising. When the air pressure to the operating pressure of the valve body, then the main valve commutation; depressurizing control refers to the increase of gas control signal pressure is reduced when the pressure is reduced to a certain value, the main valve commutation; difference pressure control valve isthe main commutation at both ends of the pressure difference.