The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 2000
Filed:
Nov. 13, 1997
Thomas C Piotrowski, West Chicago, IL (US);
Martin Clift, Vacaville, CA (US);
Baohai Liu, Carol Stream, IL (US);
The Protectoseal Company, Bensenville, IL (US);
Abstract
A vent valve is provided wherein a pallet/diaphragm type valve is cooperatively and coactively associated with a pressure responsive liquid seal. The assembly eliminates low level fugitive vapor emissions escaping from the diaphragm/seat region up to a predeterminable liquid seal set pressure which preferably is less than or equal to the set pressure for diaphragm opening. A liquid reservoir with a sealed chamber is provided for the liquid seal subassembly. Fugitive emissions from a tank or the like that is associated with the vent valve enter the sealed chamber and are there contained until the pressure therein is sufficient to displace the sealing liquid to an extent sufficient to open the sealed chamber. The valve assembly can be used as a pressure vent, as a vacuum vent, and as a combination pressure and vacuum vent. Optional features, such as a constant liquid level controller, a sight glass, a signaling device, or the like can be provided.