| Flood Defence is very important in parts of the world; | | | | the valve should be (above or below the water), |
| it can stop homes and towns being destroyed, peoples | | | | pressure head operation, the cost and regulation of |
| well being taken away from them. Dams are the main | | | | precision. |
| type of flood defence and in every dam / floodgate | | | | Some of the different valve types used in Flood |
| valves are one of the main components that allow | | | | Defence are listed below: |
| them to function correctly. The valves used have a | | | | Fixed Cone Valves |
| range of design requirements and more than often are | | | | These valves are round pipe sections, they have a |
| located in Dams right at their base. Usually the most | | | | cone at the end where the water discharges and an |
| important requirement of a Flood Valve is its energy | | | | adjustable sleeve gate. |
| dissipation (and obviously the regulation of water flow). | | | | Hollow Jet Valves |
| Due to the weight of Water when it has built up the | | | | These are used for flood gate discharge and are a |
| force at which it exists the dam is extremely high, the | | | | type of needle valve, inside the pipe is a seat and |
| flow of the exiting water must be dissipated otherwise | | | | cone. |
| it has the potential to damage structures and erode | | | | Ring Jet Valves |
| nearby soil and rock. | | | | These valves are very similar to the Fixed Cone |
| There are some other requirements that a valve must | | | | Valves, but they discharge water in a narrow stream |
| do, other requirements must take in to count where | | | | due to an integral collar. |