초록 ▼

A valve for preventing water hammer includes a speed reduction device for reducing a speed at which the valve may be closed. A method of preventing water hammer includes closing a valve at a fire hydrant after extracting water from the fire hydrant, in which the valve comprising a speed reduction de

A valve for preventing water hammer includes a speed reduction device for reducing a speed at which the valve may be closed. A method of preventing water hammer includes closing a valve at a fire hydrant after extracting water from the fire hydrant, in which the valve comprising a speed reduction device that increases an amount of time needed for closing the valve, and operating the valve to close the valve comprises operating the speed reduction device.

대표청구항 ▼

1. A valve for preventing water hammer, said valve comprising: a gate valve having a gate that is translated in and out of a channel of the valve by rotation of a valve handle; anda speed reduction device for reducing a speed at which said valve may be closed, the speed reduction device comprising a

1. A valve for preventing water hammer, said valve comprising: a gate valve having a gate that is translated in and out of a channel of the valve by rotation of a valve handle; anda speed reduction device for reducing a speed at which said valve may be closed, the speed reduction device comprising a gear train with a gear ratio such that a number of rotations of said valve handle results in a lesser number of rotations of a screw that translates said gate with respect to said channel;wherein threads on the screw supporting the gate are reversed such that, with the gear train reversing a direction of rotation of the valve handle as applied to the screw, a clockwise rotation of the handle will close the gate and a counter-clockwise rotation of the handle will open the gate. 2. The valve of claim 1, further comprising a set of threads at one end of the channel sized for mating with the threads of a pumper nozzle of a fire hydrant. 3. The valve of claim 2, further comprising a set of threads at an opposite end of the channel sized for mating with a hose of a water truck. 4. The valve of claim 1, wherein the screw comprises a worm gear. 5. The valve of claim 1, wherein the gear train consists of two gears of two different sizes. 6. A method of preventing water hammer, the method comprising: closing a valve at a fire hydrant after extracting water from said fire hydrant, the valve comprising a gate valve having a gate that is translated in and out of a channel of the valve by rotation of a valve handle, and closing the valve comprising rotating the valve handle in a clockwise direction;wherein the valve comprising a speed reduction device that increases an amount of time needed for closing said valve, and operating said valve to close said valve comprises operating a speed reduction device such that said increased amount of time needed for closing said valve prevents an occurrence of water hammer associated with said closing of said valve;wherein the speed reduction device for reducing a speed at which said valve may be closed comprising a gear train with a gear ratio such that a number of rotations of said valve handle results in a lesser number of rotations of a screw that translates said gate with respect to said channel;wherein threads on the screw supporting the gate are reversed such that, when the gear train reverses a direction of rotation of the valve handle as applied to the screw, a clockwise rotation of the handle will close the gate and a counter-clockwise rotation of the handle will open the gate. 7. The method of claim 6, further mating a set of threads at one end of the channel with the threads of a pumper nozzle of a fire hydrant. 8. The method of claim 7, further comprising mating a set of threads at an opposite end of the channel with a hose of a water truck. 9. The method of claim 6, wherein the screw comprises a worm gear. 10. The method of claim 6, wherein the gear train consists of two gears of two different sizes.