Hello! I'am new in the forum. I m currently working on a project to test some valves ( pvr, check valves). I'm trying to design the hydraulic circuit. I have a centrifugal pump, I also have a variable frequency drive. for this, I don't know if i should connect my check valve directly to the pump and use the VFD to control the rotation of the pump. or stay ultimately on a fixed speed and use instead a valve in my circuit to control flow. I would appreciate it if you guys have some idea for building this kind of bench tests.. Thank you for your time.