Thursday, August 23, 2012

Flood Defence

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

No comments:

Post a Comment