"Tom" wrote in message
...

Perhaps you could supply the make & type of pump and describe the
the the way in which it is plumbed to the tank? What height does
the pump have to draw the oil from the tank?

Also, how do you know that "the pump circulates to the tank at
essentially zero pressure."?

Tom

It's a cheap Prince 11gpm two-stage pump. Cheap. Hooked up to a 1725RPM
2HP pool pump motor. Lovejoy coupling.

The pump is _below_ the fluid level in the reservior. Actually, about 8"
below.

I have a pressure gauge on the HP line, just before the ONLY restrictions in
the bypass circuit -- namely, the OC bypass valve itself.

The return lines are larger than the HP line. The HP line is 1/2", 3-wire,
neoprene coated standard stuff from NAPA.

LLoyd