A key advantage of rotary positive displacement pumps is providing consistent flow regardless of changes in liquid viscosity or differential pressure. But should a downstream blockage occur, pressure will rapidly build and may exceed the rating of the pump, drive equipment, system, or any combination thereof, with the potential for damage and unplanned downtime. For this reason, overpressure protection must be used, and pressure relief valves are the most commonly used form of overpressure protection for rotary positive displacement pumps.

All positive displacement pumps work by first expanding a cavity between the casing and one or more moving parts to create a partial vacuum, so atmospheric pressure can force liquid into the pumping chamber through the inlet port… read more.