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

I have the same question about worst case failure of a 19 yr old Watts back flow preventer. The only obvious problem is a drip leak at the top vent caused by the diaphragm stem piston 0-ring leaking. A new or reworked top would be required due to pitting in the o-ring bore. There have been no unusual discharges of the relief valve. The ball valve handles are still intact and the valves open and close ok.

What other part(s) failure could cause a wide open relief valve dumping huge amounts of water? I have thought if the diaphragm fails that could occur. Would there likely be a warning first? Any other serious failure modes?

Yeah what he said. Save up enough recycled back flows and your boss will take you to a trip to Hawaii. Glad to know there are testers over there cause we saw some wacky irrigation

Is the valve being tested regularly? Manufacturers recommend, and many jurisdictions require that backflow prevention devices be tested by certified personel on a yearly basis. I usually recommend the replacement of backflow preventers when one of the following comes up... a device fails and the o.e.m. is out of business (Beeco), the device fails and it is more cost effective to replace it than to repair it, or if the customer is interested in replacing the valve anyway due to asthetic issues or increased volume demand. Remember, the valve is there for a reason, there are test cocks installed on it for a reason and if it is not being tested, how can you know if it is doing its job.

What sort of failure are you expecting from these valves? About the only thing I can thing of that could go wrong simple due to age is the handles rusting off or rusting over so much the valves can't be turned anymore and get stuck in an open or closed position. Worst case, you simply replace the whole unit.

you can replace the rusting handle and nut with stainless-steel ones

My sprinkler system uses a FebCo 765 (3/4") BPV right now. It's probably 17 years old. The ball valve handles (inlet and outlet) are mostly rusted out but the BPV looks OK on the inside. I am concerned about those valves failing in some really serious way if I just ignore them.

If the handles are rusted, does that usually indicate a problem inside the ball valves?

Is there any way to know when they're about to fail or would you all just replace them right away?

Is replacing one of these ball valves something you'd recommend for an amateur or would this be the time to call in a pro?

Thanks,