Patent ID: 8678026
Filing Date: 2014-03-25
Classification: E04H,F16K,Y10T

Abstract:
1. In an automatic vacuum-relief valve apparatus for liquid suction systems which includes a liquid flow line with an inlet and an outlet, and a relief-air flow channel which communicates with the liquid flow line upon inlet blockage, the relief-air flow channel being isolated from the liquid flow line during normal operation and open to the liquid flow line upon inlet blockage, the improvement comprising: a valve device forming an air passage adjacent to the liquid flow line and allowing air into the liquid flow line in response to suction increases therein caused by inlet blockage; a vessel defining a chamber filled with liquid in communication with the liquid flow line; a rotary shaft extending through the chamber, one end of the shaft supporting the air-passage-forming valve device adjacent to the liquid flow line, the opposite end of the shaft; supporting a piston distal from the liquid flow line and responsive to suction increases within the chamber due to inlet blockage causing suction increases in the liquid flow line, the piston actuating rotation of the shaft thereby moving the air-passage-forming valve device from its isolating position toward its opening position in which the air passage is in communication with the relief-air flow channel to reduce the suction by bleeding air into the liquid flow line.