Flushing

Annual flushing is enough for many systems, but some water and emitter combinations require almost daily flushing to control clogging. If frequent flushing is required, automatic and semiautomatic flushing valves are recommended at the ends of the laterals. Flushing

A water velocity of about 1.0 ft/s is required to flush fine particles from lateral tubing. For 1/2-in.-diameter tubing this is about 1.0 gpm. Flushing

What do you do with the flush water?

Flushing The size of the supply manifold may be dictated by the flushing requirements rather than the irrigation water supply requirements. The flush valve must also be correctly sized to ensure sufficient flow is achieved

During Tape Flushing: The pressure needed at the beginning of the tape depends on: 1.Friction along the tape: water that flushes 2.Friction along the tape: water that exits the emitters …And

During Tape Flushing: 3.Pressure required at the end of the tape in order for water to leave the flushing manifold friction in the flushing manifold, friction through the flush-out valve, elevation between the tape itself and the final discharge in the air downstream of the flush- out valve, elevation change along the flush-out manifold, and friction loss of fittings

Consider this: Adjustable pressure regulators have advantages for flushing Thick walled tape may be necessary for flushing, but not for normal operating pressures Pump needs to be sized for flushing, too.

Consider this: Losses through the flushing valve can be higher than the flushing manifold Rule of thumb: increase the lateral flows by 30% when operating at the flushing pressure

Consider this: Better results may be obtained by flushing part of a zone. Locate flushing valves next to each other.

Flushing Manifold Design Flushing manifold needs to carry flow that is exiting the laterals Minimum flow rate in flushing manifold must be 1 ft/sec (1.5 ft/sec in NE). Remember to account for height of flushing valve.