Bsperr
Member
I've really enjoyed reading the threads and learning more about plumbing. I'm planning my first real plumbing job that will require permitting and inspection and wanted to run a couple questions by you guys. I'm going to install a PRV and expansion tank in our (old) new home. It's never had a PRV, and the water pressure is at about 90psi. I have a very accessible crawl space, and there's a nice horizontal run on the cold water supply to the hot water heater where I'm going to install the expansion tank and a nice vertical run where the line enters the house where I'll install the PRV.
1. I wanted to buy a Watts expansion tank, and in the installation instructions I read online, it advises installing a backflow preventer on the line before the PRV. I went to Lowes, and all they carry is a Wellsaver brand expansion tank. In their instructions, it says no backflow preventer is necessary because the tank is designed for potable water (which doesn't really make sense to me). I've called the building inspector to see if a backflow preventer is necessary in our area, but haven't heard anything back yet. I also don't know if there's a backflow preventer incorporated into the meter. Would you all install the backflow preventer just to be safe? I've attached a picture of my proposed install.
2. This is probably a stupid question, but the PRV and backflow preventer both have integral union gaskets to attach to threaded pipe, so do I use teflon tape both on the threaded adapter on my supply line and on the treaded portions on the bodies of the PRV and backflow preventer before I hook up the union (I know that you normally don't use teflon tape when you have a gasket that does the sealing, but wondered if it might be a necessary in these cases). Thanks for your help--Brad
1. I wanted to buy a Watts expansion tank, and in the installation instructions I read online, it advises installing a backflow preventer on the line before the PRV. I went to Lowes, and all they carry is a Wellsaver brand expansion tank. In their instructions, it says no backflow preventer is necessary because the tank is designed for potable water (which doesn't really make sense to me). I've called the building inspector to see if a backflow preventer is necessary in our area, but haven't heard anything back yet. I also don't know if there's a backflow preventer incorporated into the meter. Would you all install the backflow preventer just to be safe? I've attached a picture of my proposed install.
2. This is probably a stupid question, but the PRV and backflow preventer both have integral union gaskets to attach to threaded pipe, so do I use teflon tape both on the threaded adapter on my supply line and on the treaded portions on the bodies of the PRV and backflow preventer before I hook up the union (I know that you normally don't use teflon tape when you have a gasket that does the sealing, but wondered if it might be a necessary in these cases). Thanks for your help--Brad