Fire hydrant break off valve

摘要

A fire hydrant break off valve includes an offset pivot and a lateral trigger captured between a fire hydrant and fire hydrant break off riser. When a collision breaks the break off bolts holding the fire hydrant to the hydrant break off riser, the lateral trigger is released and the valve rotates to a closed position. Force of water attempting to escape rotates the valve around the offset pivot. The edge of the valve is tapered and after rotating, the valve is pushed against a matching seat to close the valve. The match of the tapered valve against the tapered seat stops or nearly stops all flow of water from the broken hydrant.

主权项

1. A fire hydrant break off riser, comprising:
a riser body comprising:
a top flange for attachment to a fire hydrant;a bottom flange for seating against a water main;a downward facing tapered seat;pivot axle seats; andat least a portion of a trigger pocket; a valve including an upward facing circumferential valve seat adapted to seat against the tapered seat in the riser body; at least one pivot axle pivotally connecting the valve to the riser body, the at least one pivot axle residing laterally offset on an axle side of the valve between a center of the valve and an edge of the valve; at least part of the trigger pocket is formed by a break away portion; and a diagonal trigger residing in the trigger pocket at a second end, and pivotally attached to the valve at a first end, the first end opposite to the second end, wherein; the valve is held in an open position by the diagonal trigger while the second end of the diagonal trigger is restrained by the trigger pocket during normal operation; and when the break away portion breaks away, the diagonal trigger is released from the trigger pocket, the valve pivots to a closed position, and the upward facing valve seat is forced against the downward facing tapered seat by water pressure.