Soil irrigation methods and apparatus

Abstract

A soil irrigating system includes a plurality of drip tubes communicating with a supply of pressurized water to dispense a substantially continuous flow of water to the soil. Flushing valves are connected to remote ends of the drip tubes to periodically flush the tubes clean. Each flushing valve comprises an inlet communicating with a drip tube, an outlet for discharging water from the drip tube, a pilot opening arranged to introduce pressurized pilot water to the valve, and a valve element of resiliently deformable material. The valve element has a recessed configuration suitable for enabling the valve element to extend longitudinally forwardly and radially outwardly into a sealing posture in response to urgings of pressurized pilot water at the pilot opening, to prevent discharge of water from the remote end of the associated drip tube. When water pressure at the pilot opening is relieved, water pressure from the drip tube shifts the valve element to an open position to enable water to be flushed from the drip tubes. A valved manifold is provided to conduct pressurized liquid to the pilot openings to simultaneously shift the valve elements to their closed positions to prevent flushing of the drip tubes. The valve manifold is also able to relieve liquid pressure at the pilot openings so that the valve elements are simultaneously shifted to their open position by water pressure from the drip tubes, to permit flushing of the drip tubes.