backwashing
Backwash valves are the unsung heroes of many a fine hydraulic system. Seldom considered other than when in use, these handy devices simplify filter maintenance, significantly extend filter cycles and even serve to stretch the service lives of a filter’s internal components. Ensuring that level of reliable performance, says hydraulics expert Steve Gutai, is a matter of understanding the role these valves play and selecting the right one for the given application. Backwash valves are simple in concept: They reverse the flow of water through a filter and, in so doing, dislodge dirt and debris that has built up on the surface of and in the filter medium. This procedure has a couple of key benefits in both sand and diatomaceous-earth filters: First, it improves filter performance by breaking up and flushing out the near-solid cakes of dirt and oil particles that build up in the media over time. Second, it prolongs filter cycles and extends the time between major (and messy) cleanings. Third, because they minimize those invasive cleanings, backwashing helps to extend the service lives of a filter’s internal components. For all that, I keep seeing systems in the field in which backwash valves are