You want to use a Generant regulator https://www.kleen-ritecorp.com/p-32...series-pressure-regulator-1-2-in-125-psi.aspx and a DEMA 203C injector downstream https://www.kleen-ritecorp.com/p-1630-dema-203c-brass-3-8-in-c-series-injector-ryton-screw.aspx I've been running my pumps like this for over 40 years, works great.
Ok, I shut off the water for a few seconds while the pump was running and now everything is ok. Magic, I guess. thanks, jdfMEP : What do you mean by throttling the water supply? Are you suggesting that the incoming water supply has too much pressure or too much volume? I have the exact problem that was described only I have both wax and soap connected by a T to the pump and solenoids controlling which chemical is fed to the pump. This just started a few days ago. I've check that the selector switch in the bay is activating the appropriate solenoid and I blew air back thru the system with the solenoid open and got lots of bubbles in the soap so the line appears to be clear. both soap and wax are failing to feed to the bay so seems like the pump is not sucking chemicals. Appreciate any help and I'll try what you are suggesting once I understand what to do. thanks, jdf