Backflow preventing valve
US4231387A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1979 |
| Grant date | Nov 4, 1980 |
| Priority date | — |
| Expiry date | Jan 11, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/3331
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A backflow preventing valve has a body with two principal portions made of a glass-fiber reinforced plastic. One portion has an inlet port and an outlet port on a through axis, the ports opening to an inlet chamber and an outlet chamber respectively. An intermediate chamber merges with the inlet chamber at an inlet valve seat and also merges with the outlet chamber at an outlet valve seat, the valve axes and the through axis being coplanar. Inlet and outlet poppet valves are urged toward their respective seats by springs in the intermediate and the outlet chambers. There is a vent chamber open to the atmosphere and having a vent valve seat merging with the intermediate chamber. A poppet vent valve has a stem movable in a guide toward and away from the vent valve seat. The stem is abutted by a diaphragm disposed between an outer diaphragm chamber and an inner diaphragm chamber and is pressed by a diaphragm spring in the inner diaphragm chamber. There is a first passage extending through the two body portions between the inlet chamber and the outer diaphragm chamber and a second passage extending through the two body portions between the intermediate chamber and the inner diaphragm c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.