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 is
the main commutation at both ends of the pressure difference.