Patent Application
20080047615
A yard hydrant 10 has a valve body 12, a valve seat 14, a drain port or hole 16, an inlet 18 which is connected to a source of pressurized water (not shown) and an outlet 20 at its top. Connected at one end to the valve body 12 is a standpipe 22 that extends vertically and is connected to a head casting 24 at the opposite end.
The head casting 24 has an inlet 26 coupled to the standpipe 22 and a discharge conduit or outlet 28 that preferably extends downwardly and outwardly from the head casting 24 and a fluid conduit 30 that extends between the inlet 26 and the outlet 28.
Disposed within the valve body 12 is a closure valve or plunger 32 that is connected to a valve stem or actuator rod 34 that extends from the closure valve 32 through the standpipe 22 and is connected to an actuator device 36 attached to the head casting 24 such as a lever or handle. The actuating device 36 can be of any type such as a lever as shown in
When the closure valve 32 engages the valve seat 14 the hydrant is in a closed position which prevents water from flowing from the water source to the discharge conduit 28. When the closure valve 32 is in the closed position the drain port 16 permits water to drain out of the pipe 22 and into the ground. When the closure valve 32 is disengaged from the valve seat 14, the closure valve 32 seals the drain port 16 and water is permitted to enter the standpipe 22 and under pressure flow toward the discharge conduit 28.
Mounted within fluid conduit 30 is a check valve 38 that allows fluid to flow from the pressurized water source through the inlet 26 to the outlet 28, while also preventing water to flow in the opposite direction from the outlet 28. The check valve 38 may be mounted at any location within the fluid conduit 30 in any conventional manner. Further, any type of check valve may be used, but preferred is the check valve disclosed in U.S. Pat. No. 5,632,303 incorporated by reference herein in its entirety.
In operation, when the closure valve 32 is opened via the actuator device 36, pressurized water flows past the closure valve 32, through the standpipe 22, into and through fluid conduit 30 past check valve 38 and exits discharge conduit 28. Should backflow pressure from the discharge end exceed flow pressure from the pressurized water, check valve 38 will prevent the backflow of fluid into the standpipe 22 and reduce the possibility of contaminating the water source. When the closure valve 32 is moved to a closed position to block the flow of pressurized fluid residual water in the standpipes 22 and some in fluid conduit 30 will drain through drain port 16 into the ground. Residual water forward of check valve 38 will drain through the discharge conduit 28.
Thus, by adding a check valve 38 to the fluid conduit 30 one eliminates the additional expense and cost of providing a vacuum breaker to the discharge conduit of a yard hydrant.
