Dome pressure maintaining valve
US4974631A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 12, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Oct 12, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7773
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A dome pressure maintaining valve and circuit for maintaining dome fluid pressure in a pilot operated relief valve is presented wherein the dome pressure in the relief valve is prevented from dropping below a preset value even when inlet pressure at the relief valve drops to zero. The dome pressure maintaining valve incorporates a compact check valve and a back flow relief valve with the two components integrated into one piston embodiment, the valve having in communication with a body bore inlet and an outlet. The circuit provides inlet fluid flow in communication with a piston valve chamber through a passage from the inlet port through the piston under the poppet check valve and through multiport and exterior piston valve ring groove means to the outlet port when the inlet fluid pressure is greater than the outlet fluid pressure. However, when the outlet fluid pressure is greater, the poppet check valve is in a check position within the piston valve chamber and the integrated embodiment provides outlet back flow relief which is due to the greater exposed surface area to the outlet pressure above the outlet port within the piston valve chamber creating an upward force on the pisto…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.