Vent/vacuum breaker float valve assembly

Claim 1

A valve assembly for venting gas contained in a pressurized liquid system during filling of the system and for breaking any tendency for vacuum effects to be created in the system during the draining of the liquid from the system, said assembly including: a valve body defining an inner chamber and adapted at one end to permit the valve assembly to be coupled to the system during use so that liquid in the system enters the inner chamber; a float assembly; a cap fitted into the other end of the valve body to enclose said other end and to support said float sub-assembly in said inner chamber; sealing means positioned between said cap and said other end of said body; said cap having a vent port extending into said inner chamber; a movable sealing member for selectively closing the vent port; a plurality of levers coupling the sealing member to the float sub-assembly to cause the sealing member to be forced against the vent in sealing relationship therewith as liquid enters the chamber and displaces the float sub-assembly upwardly in the chamber; a spring loaded valve mounted in said cap in position to be closed when the inner chamber is pressurized but to open and break the vacuum effects of the chamber when the liquid therein is drained so as to reduce the internal pressure of the inner chamber; and a cover enclosing the cap and valve body to insulate the valve assembly and reduce the tendency of the liquid within the valve assembly to freeze.