摘要 |
<p>This invention is directed to a differential control valve. The differential pressure is maintained by differing area surfaces on a piston assembly which will be balanced at a predetermined differential established at the manufacturing operation. There is a spring member operating on two valve balls which provides a delayed pressurization of the controlled chamber. The control valve has a ball valve at the exit port to control the low pressure side of the differential control valve assembly, providing a fail-safe system with no adjustments required after manufacture if there is a pressure increase downstream.</p> |