Finished out the coolant plumbing system for the plasma cutter. Could have done something more simple, but ended up with this.
The bar drains are 1-1/2 but are NOT 1-1/2 MTP. Local pluming house had swivel adapters. Enough swivel fittings to remove the tank or any of the glued sections.
Since tank is not intended to be removed often, I put in provisions for a clean/pump out Hose connection and a valve to block the drain fill.
suction side starts with a check valve, filter then a 110v pump. The check valve seat pressure was way too much for suction use, so I modified it. Ripped out half of the spring. Now it is only a few lbs and works well. With clean out valve, check could be omitted. The pressure side dumps into drain, to fill up out of drains, but drain valve needs to be shut.
Time to fill (~13 gallons) is 1 minute, 40 seconds. Time to drain to 95% is about the same.