Chiller PVC piping

[TGTimm]

Philip--almost all of our glycol piping is sch80 PVC. Some of it is about 20 years old now, and still going fine, with no signs of brittling. None is exposed to direct sun.

The biggest problem I have with PVC is leaks at "dead" joints--those that cannot be twisted while gluing. There are always a few, and no matter how much prep and glue I use, those are the ones that eventually leak. YMMV.

[rdcpro]

[...] The biggest problem I have with PVC is leaks at "dead" joints--those that cannot be twisted while gluing. There are always a few, and no matter how much prep and glue I use, those are the ones that eventually leak. YMMV.

I had this problem at a winery client with 4 inch Sch 80 PVC. I used a thermal PVC welder to weld the joint closed after gluing...it worked pretty well, but every so often one would spring a leak, and it was a major PITA to fix in place. Some of their runs were set up with inadequate room for expansion/contraction, and although the system was usually on all the time, I suspect the flexing contributed to the leakage. A couple of times I welded the piping in-situ after it sprang a leak. Took some grinding, super cleaning and patience, because it never seemed to seal the first attempt.

But I think welding the joints helped cut down on the leaks, especially since it was pretty large pipe, with really big glycol pumps, and in a cold damp place. And while they say to use an applicator that is at least 1/2 the diameter of the pipe, I've never seen one sold big enough for 4" pipe.

Regards,
Mike Sharp

[jebzter]

I have put unions in strategic places so that the final joint is actually the union. This way I can apply the appropriate twist to all of the joints.