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US4254731A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 22, 1979 |
| Grant date | Mar 10, 1981 |
| Priority date | — |
| Expiry date | May 22, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S116/25
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An indicator device for indicating when a prechosen pressure difference has been exceeded comprises a casing having two ports separated by a resilient diaphragm with an aperture therein, and a movable member urged into sealing relation with said aperture so as to prevent leakage therethrough, the configuration of the member and the aperture being selected so that, in use, the application of a prechosen pressure differential between said ports will cause the member to partly pass through the aperture to a position whereat it is retained by the diaphragm, said member being provided with means for indicating that it has been so retained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.