Patent ID: 6481456
Filing Date: 2002-11-19
Classification: F16K,Y10T

Abstract:
Liquid treatment apparatus comprising, a pressure tank having a top, a bottom, an inlet for untreated liquid, and an outlet for treated liquid; means for pressurizing said tank so as to provide an air space in an upper part of said tank, said air space defining a level for the liquid in said tank that is below said air space, the level of liquid below said air space rising and falling in response to the pressure in said tank; a control circuit including an air pressure switch for turning said means for pressurizing said tank on and off; an air vent connected to the atmosphere on the outside of said tank; a valve adjacent the top of said tank for opening and closing said air vent in response to the level of the liquid in said tank, said valve having a hydropneumatic chamber adjacent the top of said tank, said air vent being pneumatically connected to said hydropneumatic chamber, an air line pneumatically connecting said pressure switch to said hydropneumatic chamber, a float located in said hydropneumatic chamber, said float being connected to a movable member for opening and closing said air vent, said hydropneumatic chamber having a lower end with an opening therein located below said float, an open-ended pipe having its open upper terminal end in said opening in said hydropneumatic chamber below said float, said pipe having its lower terminal end extending downwardly to the liquid in said tank so that upward and downward movement of the level of the liquid in said tank causes liquid to move into and out of said pipe through said lower terminal end; said pipe being unobstructed between said upper and lower terminal ends, the upward and downward movement of liquid in said pipe causing liquid to move into and out of said hydropneumatic chamber so that movement of liquid into and out of said hydropneumatic chamber raises and lowers said float in said hydropneumatic chamber; lowering of said float in said hydropneumatic chamber causing said movable member to open said air vent to the atmosphere, and the opening of said air vent causing the pressure in said hydropneumatic chamber to fall and thereby to cause the pressure in said air line to fall so as to close said pressure switch and thereby to activate said means for pressurizing said tank.