Neptune's Back Pressure Valves help maintain a set pressure at the pump outlet port, also known as discharge, to assure accurate metering and to prevent syphoning. Neptune Back Pressure Valves also assure proper metering pump check valve operation when the system pressure against which the pump is injecting fluid is too low.
Back pressure valves are a required accessory when metering pumps are pumping to a low pressure injection point below the tank level or when pumping from a bulk tank with a high head pressure.