SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

lol.. I've installed many rp's below ground with 'eliberate ' drainages.. In My area. All houses that are lake front property must have a RP on the domestic service line. People pay good bucks to keep it out of sight

Quoted from "wsommariva"

Yes I now realize that. I think I'll stick with the double check unit. In my case the risk is low. And I am uncomfortable with the PVB and potential floods. And it seems to be an adequate device although not the best perhaps.

Question about installation and testing. I'll install it vertically in this order. Water meter, sprinkler shut off valve, sprinkler drain and then the DCV. This ok?

To test it, if I turn the water off to the system after the meter, open the drain and then open the DCV unit, NO water should come out. Is this a good test?

Thank you

YOU ARE AN EFFING IDIOT !! ~ to do what you describe is, in New Jersey, to make your house unsaleable. I bet you'd remove the emergency brakes from your cars, because you believe there's a "low risk" of your brakes failing. Understand one important thing. If fate decides that it is your part to be the chump that a "backflow event" happens to, insurance companies will gut you like a fish.

Fix the existing system inadequacies. You put them in. Man up. Look in the mirror. Make it right. Don't go looking for any assent or compliments for your doing the wrong thing.

Of course your town official is wrong. New Jersey did not change their building codes. You are too much of an idiot to actually visit your library and read the truth. It's there. They keep copies of codes and ordinances in the reference section. Only toxic-rated backflow is allowed. This is law. Even your chubby Governor can't give you an exemption. There are towns that are clueless about how the plumbing rules have changed. An official that learned his stuff in the 70's or 80's may not know it's a new deal these days. But insurance companies know. No one in their right mind makes himself a possible target over his nonsensical high opinion of his own do-it-yourself work.

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PVBs work all the time without gushing water on a continuing basis, but most of them are installed by people that don't install screwed-up sprinkler systems that cause the supply pressure to drop too low. It's the zones that need to be fixed. Not the backflow prevention.

Pros do not use the Toro PVB - we can get brass ones for not much more money. Although the Febco is going to be most common, the Wilkins 720 is physically stronger, and it's the one I prefer. Curiously enough, it is also the one PVB I commonly see that can spill water whenever the pressure drops very low. Not a problem on my own installs, with the exception of well-water systems with poorly performing wells, where there can be a pronounced dip in pressure when the system is first opened in the spring, at the point when I cycle from one zone to the next. (the PVB does not keep spilling water, but seals tight when the pressure goes back up)

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More details about your particular system would help. If the only time your PVB spills, is when you cycle from one zone to the next, then you look to set up a delay between zones. That way the pressure is back up when the next zone activates. If the PVB spills when any zone is opened, then you have to deal with each problem zone, and you might as well start with the drains. If you didn't have drains to remove, the next thing to look at would be whether you could reduce the flow in the zone, by reducing nozzle sizes. The very last thing to try, short of redesigning the system to have more zones, with fewer heads on each zone, would be to have heads with built-in check valves, although that is more of a solution for sloped properties, as water will be draining from the lowest heads on a zone.

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One more thought about a possibility for keeping the supply pressure up while cycling from zone to zone, is to throttle down the flow controls on each valve, if by chance you have flow controls on your zone valves.