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

Quoted from "Lunker"

Thanks! any recommendation for a removable one?

No. None whatsoever. Removing an RPZ is something I would never do. I certainly won't store them myself, and I would not count on a homeowner to never misplace it on his own.

I don't think you need to remove it in the winter. Just winterize per instructions. I know Febco PVBs are popular. I'd feel comfortable with Febco and Wilkins.

But, if you really want to remove it, I GUESS pvc unions would work. Check with a qualified plumber. I use pvc unions on my 3/4" PVB. On my 1" PVB, no unions, it's permanent.

By the time you go through the removal of an RPZ and covering up the union ends, you could have just as easily winterized it in place.

I currently have a PVB backflow preventer, but I am looking to install a fertilizer injection tank so it seems I need to go the route of RPZ. I had one plumber install the PVB which worked well, but then I didn't winterize it and it ended up cracking. I had another plumber install the second one and I don't think they knew how to test it. Who would test a RPZ if I installed one? An irrigation company or a plumber?

In looking at the R value factors for the insulating pouches, I wouldn't feel comfortable leaving the RPZ out in the cold even with such a pouch. If the unit is removed for winterizing each fall, should it be tested each spring?

The testing equipment appears to be very expensive. Is this something the average homeowner could do?

Quoted from "whitty"

I currently have a PVB backflow preventer, but I am looking to install a fertilizer injection tank so it seems I need to go the route of RPZ. I had one plumber install the PVB which worked well, but then I didn't winterize it and it ended up cracking. I had another plumber install the second one and I don't think they knew how to test it. Who would test a RPZ if I installed one? An irrigation company or a plumber?

In looking at the R value factors for the insulating pouches, I wouldn't feel comfortable leaving the RPZ out in the cold even with such a pouch. If the unit is removed for winterizing each fall, should it be tested each spring?

The testing equipment appears to be very expensive. Is this something the average homeowner could do?

Forget the RPZ at this point. You almost certainly do not have enough pressure to allow for an added RPZ to take away an additional 10 psi of system pressure.

Quoted from "whitty"

................In looking at the R value factors for the insulating pouches, I wouldn't feel comfortable leaving the RPZ out in the cold even with such a pouch. If the unit is removed for winterizing each fall, should it be tested each spring?

The testing equipment appears to be very expensive. Is this something the average homeowner could do?

Testing an RPZ is entirely outside the reach of a homeowner, when it comes down to it, because there is a paper trail involved in the testing of safety devices like an RPZ. A homeowner's word counts for nothing at all. The word of a licensed tester of backflow preventers counts a whole lot more.

a PVB has a construction that admits air into the device, when the supply pressure drops below a certain point - this air opening is the primary protection the PVB gives you, and as long as the PVB is the highest part of the sprinkler system, the air opening and gravity is what keeps system water from getting back into the house plumbing

RPZ is always the best way to go if you are adding chemicals to the system.