Pressure unloading pilot operated regulator having pressure limiting check valve

摘要

A pressure unloading pilot operated fluid pressure regulator having a throttling element for controlling fluid flow. A pilot amplifier senses regulator outlet pressure and supplies suitable loading pressure coupled from an inlet supply pressure line through a variable flow restrictor to the throttling element. A check valve has a preset differential pressure defined between the check valve inlet and outlet and is mounted in parallel flow with the flow restrictor to limit the maximum differential pressure across the throttling element to the preset differential pressure of the check valve.