Fire hydrant security integrated flow control/backflow preventer insert valve
Integrated flow control backflow preventer valve (“IFCBPV”) for new and existing wet- and dry-barrel fire hydrants, with barrel drain assemblies for dry-barrel hydrants, and hydrants equipped with such IFCBPVs, are presented. An exemplary IFCBPV can have a retaining screen comprising equidistant concave radial spokes intersecting at a central ring structure, a freely suspended check ball, and a lower ball seat with a seal. The upper surface of the retaining screen can be affixed to the hydrant's axial shaft, and can thus be used to open and close the hydrant via the ball. Alternatively, the retaining screen can be fixed and the axial shaft provided with a cup on its bottom that mates with the freely suspended ball that is caged between the retaining screen and the ball seat. An exemplary barrel drain assembly can comprise a spring-loaded piston, or alternatively, a check ball design as in the main barrel.
1. A dry-barrel fire hydrant valve, comprising:
a valve body, comprising:
a movable retaining screen at an upper end;
an axial shaft connected to an upper portion of the retaining screen;
a ball seat at a bottom end;
a ball; and
one or more barrel drains integrated within the valve body, each drain comprising a ball within a tube, the tube having a narrower diameter at its ends than in its middle portion, and the ball having a specific gravity somewhat higher than that of the surrounding fluid,
wherein the valve is opened by a user causing the moveable retaining screen to rise, allowing the ball to be pushed upwards by fluid pressure, and closed by causing said retaining screen to push the ball downward and seal on the ball seat;
wherein the ball is caged between the retaining screen and the ball seat, the ball has a specific weight slightly greater than the specific weight of a fluid to be sent through the valve,
wherein, when the said retaining screen is raised:
in forward flow the ball is held in a position adjacent to the retaining screen such that forward fluid flow is facilitated, and in backwards flow the ball seals in the ball seat, thus preventing backflow.
2. The dry-barrel fire hydrant valve of claim 1 , wherein, each barrel drain further comprises:
a horizontal inlet port and ball seat and a downstream angular positioned ball seat and outlet port,
a horizontal pipe in fluid communication with said inlet and outlet ball seats and ports; and
a ball with a specific weight greater than the specific weight of a fluid supplied by the fire hydrant,
wherein when the valve is open the ball is pushed to block off the outlet port, when the valve is closed the ball seats in the ball seat, and when a fluid pressure is applied form the outside of the hydrant at the outlet port, the ball is pushed to block off the inlet port, preventing backflow into the hydrant.
3. The valve of claim 1 , wherein the valve body has an outside diameter with a mating outside thread arranged to mate with a hydrant's lower interior thread such that when installed the valve is not visible from the outside.
4. The valve of claim 1 , wherein said valve seat further comprises an “O” ring or other fluid sealing material.
5. The valve of claim 1 , wherein the retaining screen has a concave surface on its upstream side, and has equidistant radial spokes meeting at a central ring, and wherein in forward flow the ball is held in position by the retaining screen, and fluid flows between said spokes and through said ring.
6. The valve of claim 5 , wherein the central ring is at substantially the axial center of the retaining screen and the valve body.
7. The valve of claim 1 , wherein the ball is self-cleaning.
8. The valve of claim 5 , wherein each radial spoke has a tapered trailing edge and a flat leading edge.
9. The valve of claim 1 , wherein the valve body has a flow transition zone to minimize hydraulic head-loss when the valve is in the normally open position.
10. The valve of claim 2 , wherein the inlet port of the drain valve has a slightly smaller diameter than a drain hole of a hydrant into which the valve is inserted.
11. The valve of claim 1 , further provided with fastening means to mate with fastening means of an existing fire hydrant, such that it can be easily retrofitted therein.
12. The valve of claim 11 , wherein said fastening means include one or more of outer threads or fasteners to match or mate with inner threads or fasteners of a conventional existing hydrant “seat ring”.
13. The valve of claim 1 , wherein at least one of:
the valve body has an outside diameter with a mating outside thread arranged to mate with a hydrant's lower interior thread such that when installed the valve is not visible from the outside, and
The valve seat further comprises an “O” ring or other fluid sealing material.
14. The valve of claim 1 , wherein the retaining screen has a concave surface on its upstream side, and has equidistant radial spokes meeting at a central ring, and wherein in forward flow the ball is held in position by the retaining screen, and fluid flows between said spokes and through said ring.
15. The valve of claim 14 wherein the central ring is at substantially the axial center of the retaining screen and the valve body.
16. The valve of claim 1 , wherein the ball is self-cleaning.
17. The valve of claim 1 , wherein each radial spoke has a tapered trailing edge and a flat leading edge.
18. The valve of claim 1 , wherein the valve body has a flow transition zone to minimize hydraulic head-loss when the valve is in the normally open position.