If you're working on sites where the primary water source is lakes, ponds, streams or effluent, it's very likely that you deal with "dirty" water. Since the dirt and debris from this kind of water can choke an irrigation system, picking the right equipment is vital and nowhere is this more vital than in the selection of the correct remote-control valves.
When you select a remote-control valve for a dirty water application, make sure it has filtration features incorporated into the valve by the manufacturer. This is a very important , because not all valves have filters and the area on top of the valve diaphragm and the solenoid area is extremely susceptible to damage from fine particles of dirt and debris. The best method for filtration manufacturers employ to prevent dirt from contaminating the valve and interrupting operation is the "self-flushing" screen.
A filter or screen that is self-flushing prevents water containing dirt and debris from entering the top of the diaphragm and the solenoid. Located on the bottom of a valve's diaphragm or inserted into the side of the valve body with a tube connected to the base of the solenoid, the screen or filter positioned in the stream of water running through the body of the valve. The water flow continuously flushes the filter screen, dislodging particles and debris before they can accumulate and clog the filter.
One manufacturer's valve, which is particularly effective in dirty water, is the Rain Bird series of scrubber valves. This series of unique valves have a scrubbing action, which occurs every time the valve is opened and closed. The fingers of the plastic scrubber removes dirt and debris by scraping the stainless steel filter screen clean as it moves up and down with the diaphragm. The action constantly breaks down debris to prevent build-up and clogging.