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:
Dec. 08, 1992
Filed:
May. 20, 1991
Applicant:
Inventor:
William H Zebuhr, Nashua, NH (US);
Assignee:
Vaughn Thermal Corporation, Salisbury, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K / ; F16K / ; F16K / ;
U.S. Cl.
CPC ...
417 41 ; 122 131 ; 126362 ; 137444 ; 137446 ; 13762566 ; 222 67 ; 222249 ; 417393 ; 417397 ;
Abstract
A water heater (10) has a pressure-transfer module (20) interposed between an external pressurized-water circuit and the water inside the water-heater vessel (12) so that the water is at atmospheric pressure and can thus have a free upper surface. A shut-off valve in the inlet (14) to the pressure-transfer module (20) is controlled in accordance with the water level as detected by a float (74). If the water level falls below a predetermined minimum or exceeds a predetermined maximum, the shut-off valve closes so as to prevent further flow into the water heater (10) from the upstream side of the exterior circuit.