RE: Perry Pumps and regulators
LNEWQBAN,
This is a back plate mounted pump.
Bottom part, what you say, pump, is bolted in the backside of the crank case, the double arrows is the pulsating crank case pressure.
From the pump outlet the fuel is pressed through the valve of the pressure regulator, in the chamber with membrane and above that membrane the adjustable spring.
The valve of the regulator is closed when the outlet pressure of the pressure reducer does get the wanted pressure level.
Adjusted spring force / membrane surface = pressure < pounds/square inch>
The demand of the engine will open the valve a little and the position later is controlled by the membrane during operating, so supply of fuel to the engine is under constant pressure of the regulator.
I do not know the wanted pressure of this pump for normal operation but we did see the pressure of the VP 30 was a ideal 0,25 PSI, and that's about 6,56 inch water gauge. (167 mmwk)
After the proper pressure is adjusted, depended of the type and adjustment of the carb, the outlet pressure can be lower but we do not know.
Cees