US Patent 9176505 Backpressure regulator with easy pump start-up

A system and method for automatically performing start-up and overpressure relief functions in association with a primary fluid carrier such as, for example, a liquid handling pipeline or tank. The system includes a main valve for primarily exhausting air from the system as it fills with a liquid. A start-up pilot device is also provided for exhausting air from the system upon start-up, but prior to the main valve opening. Finally, an overpressure pilot device is provided to relieve overpressure situations during normal operation.