TPR drain line I’m finding ASTM-0-3309-UPC-SDR on Manufactured Homes older 70-80 time frame. Its not CPVC Is this stuff approved?
I think the mobile home mfgs got away with that stuff. However, I always explain the function of the TPR and how the escaping water could be scalding hot, possible near steam in a worst case situation, and under pressure besides. Then I “strongly advise” an “inexpensive and simple fix” of removing the CPVC and replacing it with copper. Also, I tell them it is in the realm of the average DIY person but a plumber should do it if they are uncomfortable doing plumbing. I explain the material is easily available at the local hardware emporium, make the pipe to fitting solder connection outdoors and when it cools, screw it into the TPR valve.
Down here in San Diego it seems to be common. And out where I live in East County, El Cajon seems to be the world’s largest manufactured home city. The plumbers here don’t have any problem with it.