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

Despite it's strength, sch 80 pvc wouldn't be used indoors. You can, however, use sch 40 CPVC pipe and fittings indoors. Otherwise, go with copper. And definitely go through the exterior wall with copper.

Those expensive shutoffs are a service convenience for when customers aren't home, and you must winterize the system completely.

If you really expect to leave a PVB filled with water over the winter, you can expect it will need repair or replacement the following spring, and if you aren't going to treat a PVB in that shabby manner, then you don't worry about so-called freeze-resistant PVBs.

The freeze resistant model I'm most familiar with has an internal relief that is designed to only open under very high pressure, and let water run out from under the device cover. This protection would only work with the water supply turned on. I don't expect this relief is something that can reset itself, so a replacement part would probably be in order next season. If the internal relief wasn't in place on this particular model, the water would freeze and crack the plastic cover. That is sort of a six-of-one half-a-dozen of the other, so far as freeze damage goes.

As long as the system is properly winterized in time, the PVB will survive any winter temperatures in its outside location. The only important precaution is to have a drain valve open on the plumbing supply, to release any water that manages to get by the system shutoff valve.