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

outdoors - always outdoors

IF you attempt to install a PVB indoors, there's several things that you have to consider. For one, I believe there are additional code requirements usually step in and require the drain to handle a certain level of flow. This flow requirement is usually what a worst case senario would be, which is basically the same as if a pipe had burst. Search the history of this web site and you can find instances where these PVB have not just leaked but forcefully spewed huge quanities of water. You got to be able to handle the quanity, as well as the direction of where all this water might go.

Then on top of that, you have to consider service. Even if you plan on servicing the system yourself, perhaps the next home owner isn't. It's much more difficult for an irrigation contrator to deal with a system when the backflow preventor in indoors rather than readilly accessable outdoors.

There are just a few of the REASONS for Wet Boots answer.

If your worry is the PVB freezing, you should be able to install it with unions so that when it comes time to winterize the system, you simply remove the PVB and store it indoors. If you go this route, get an extra set of union pieces so that you can attatch dead-end nipples over the ends of the pipe while the PVB is removed (avoid insects taking up residence in your pipe during the winter).

Just install the PVB outdoors and follow the manufacturer's care instructions as though your childrens' lives depended on it.

If the height of the heads and plumbing in the sprinkler system make a PVB an access problem, then you have to change to a RPZ device.

I install RPZs outdoors, and they stay in place, even in sub-zero temperatures. Of course, all the water is removed from these devices prior to winter. Unfortunately, that removal requires partial disassembly of the RPZ. Follow mfr directions and you will be fine.

There are two models of RPZ that appear to be able to be winterized with a small (warm, but not hot, air temperature) compressor right through the device. One is the Watts 009, and I use those. The other is one I don't have experience with, and that is the Conbraco. What gives the Conbraco RPZ this appearance is the upward orientation of the check valves, and the lower-down location of one of the testcocks, needed to drain the lower portion of the device. (just the same, the first time I winterize one of those, I will still do the necessary disassembly to confirm that all the water is out)

To protect the PVC above ground, you can paint it to help reduce the effects of UV light. But even better would be to transition from PVC underground to copper above ground. Obviously the copper is impervious to UV light, and you're unliking the crack the copper should you ever hit it with a weed-eater.

All it takes is a PVC male and copper female and make place these joints under ground. You could even build "feet" into the copper pipe to support the backflow device without the risk of it getting knocked over and damaging the underground plumbing.

The attatched image is a CRUDE drawing of how you could build feet. In the drawing, the small tubing at the ends represents the PVC. The larger tubing represents the copper, and the box represents the backflow device (RPZ or PVB).