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This post has been edited 1 times, last edit by "Central Irrigation" (Apr 15th 2013, 9:51am)
It is true that I have noticed the PGP heads leaking around the valve body seal but the ones that have been replaced by Orbits do not leak nearly as much. I have a few heads left to replace with Orbits this spring. That being said, the system works fine after I go through all of the valves and replace the diaphragms, but I shouldn't have to be doing this as often as I do. The main problem that happens is that several zones are not shutting off properly ( even with a 20 minute delay between zones ) and this leads to wet spots in the yard around the heads with not enough pressure to operate the one zone that should be sprinkling. I have good pressure when the valves operate properly but it just doesn't happen for very long after going through the valves. What is your opinion on replacing the SRV tops with PGV tops with flow control ( easiest to do without cutting out and going with a different brand ) and also installing the 100 mesh filter as you mentioned above? ThanksYou should save your money, and instead, install a 100 mesh inline filter to your sprinkler supply line. That shale you referred to is the sole reason your valves are failing.
Edit: It is possible that your systems dynamic pressure is too low to operate the valves effectively. I wpuld say, based on your numbers, you should check for any and all leaks. PGP heads are notorious for leaking while operating, and can rob a system of critical pressure. Personally, since you state this is a recurring issue, i am more apt to believe that this is a water quality and design issue, more so than a component issue. Although, leaky heads and the like would exaserbate the problem.
Anybody else care to comment?
Will flow control adjustment help the diaphragms to close ( by putting a little more pressure on the diaphragm spring ) when the zone turns off at the controller? Also, there is no pressure tank on the well water supply. The well is for irrigation only, and my house is connected with city water.Flow-control valves are wanted here. Also, filtration should always be employed on well water. It isn't that every well gives damaging amounts of particles and sediment, it's that the hassles and expense of cleaning things up, after the fact, are far beyond what it costs to filter the water in the first place.
Is there a pressure tank in the well-water supply?
Okay that makes sense to me if the flow control plunger isn't operating through the spring but on the diaphragm itself. That's why I'm asking these questions, just trying to learn and draw from others' experience. I have a lot of experience with industrial bypass and pressure regulating valves that do operate by loading / unloading a spring. The springs in these control valves are pretty flimsy compared to most springs, and it doesn't look like manufacturers offer any stronger spring for operating. They diaphragms appear to engineered to close (make contact with the valve seat) with the spring & gravity before being held closed by the larger surface area of water from above the diaphragm.No, it does not add pressure to the spring. In fact it actually does the opposite. The flow control actually makes contact directly to the diaphragm, not through the spring. A flow control only limits how far a diaphragm can open, thus controlling how much water can can flow through the valve. There is a case that could be made that if using a flow control, the diaphragm would have less distance to travel in order to close. However, the diaphragm will only open as much as the flow dictates. So i guess i fail to see how a flow control would help.