Backflow preventer
US8037899B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 30, 2009 |
| Grant date | Oct 18, 2011 |
| Priority date | — |
| Expiry date | Feb 5, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/88054
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A first check valve has a narrow flow path portion (68) formed between an arcuate portion (46) of the outer periphery (45) of a support member and a second enlarged-diameter portion (11) of a casing. The narrow flow path portion (first portion of an intermediate flow path) is in fluidic communication with a back-pressure chamber (50) defined in the support member at the rear of the top of a valving element through a communicating passage (67) including a gap (66) between the outer periphery of the valving element and the inner periphery of a large-diameter portion (38) and grooves (27) on the rear surface of the top of the valving element. Thus, a low static pressure of fluid flowing through the narrow flow path portion is introduced into the back-pressure chamber to move the valving element by a large differential pressure during the supply of fluid, thereby allowing the valve opening to become larger than in the conventional apparatus and enabling a reduction of pressure losses. An intermediate chamber has a pressure chamber (130) defined therein by using a rigid partition. A high-pressure chamber (131) of the pressure chamber is in communication with the upstream side of the fir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.