REMOTE AIR OPERATED PRV-45
In NU-TECH PRV-45 Loading Pressure - either air or inert gas is applied to the top of the diaphragm by the loader to open the main valve against the valve spring and inlet pressure.
After the valve is open, more loading pressure is applied to the top of the diaphragm to keep the valve open while building up the desired reduced pressure under the diaphragm and to restore equilibrium under flow conditions. Reduced pressure from the down steam piping system is applied to the bottom of the metal diaphragm through an external impulse line.