Gordon-Piatt Low Fire Bypass Pressure Regulator

Description:
Oil burners which have low fire start fuel control systems must deliver oil to the nozzle reduced pressure for low fire. This is normally accomplished by diverting a portion of the oil pump delivery through a by pass return line to the tank. The amount of oil delivered to the nozzle versus that returned to the tank is controlled by a device which limits or meters flow, thus an oil bypass regulating valve or an oil metering valve is used for this purpose.

Adjustment Procedure:
Using a screw driver, remove cover screw and gasket to gain access to the adjustment mechanism.  Use 1/8" Allen wrench to turn pressure adjusting screw clockwise to increase pressure and counter-clockwise to decrease.