Drop is one type of connection which is mostly used for change or diversion of pipeline. Gravity of the pipeline result fluid to transported through the slope of it. The gravity is the only reason for this motion and there is no any pressure inside. Generally, for preventing from increase in depth of pipeline and fluid rate, the slope of pipeline considered to be in the range of 4% – 8%.
Some times for the environmental conditions such as facing with obstacles, it’s needed to increase the depth in a point. This change could done by drops.
We have two kind of drops: sloop drops and manhole drops
In manhole drops, the fluid insert to the manholes and drop through the shaft and at the bottom of manhole exit through outlet. In places that the depth of drop is high, in design of drop some measures will be implemented for reduce the impact caused by falling fluid at the bottom of the drop.
In sloop drops, the pipeline has fracture at considered point and after passing some distance, by another fracture, continue its own slope. Normally, these fractures are with the degree between 30 and 45.
Moreover, drops can be used for reducing the flow rate in the pipeline. If more reduction is required, it’s possible to use several drops beside each other.