Should I use PVC or ABS pipes for a swimming pool control system?

Question

I live in Southeast Idaho, an area with all four seasons. I have an in-ground pool with PVC plumbing which was sort of hacked together by the former owner. The system includes a solar heater on the roof, sand filter, and SWG (Saltwater Generator), 1HP pump.

A former contractor friend suggested I replace the aging, patched-up pipes (the exposed ones near the control system, not the underground pipes) with ABS because it is apparently less vulnerable to cracking in the cold should some water remain, and is softer, allowing it to absorb some of the initial shock of pump's pressure when first activated.

A swimming pool professional, though a bit used-car-salesmanesque, said PVC is "the best". Which, if either, of these are most appropriate for low-maintenance long-term use?

Answer 1

PVC is a good choice, provided that it is properly installed and maintained. A proper installation includes shielding the PVC from UV light, which is the primary means of premature aging. UV light will eventually turn PVC into a brittle mess.

ABS on the other hand tends to not become brittle with sun exposure, but to deform and is generally softer. As a result, buried ABS pipe seems to be at a higher risk of crimping, impeding water flow.

In either case, you should paint your exposed pipe, which probably wasn't done, and is the primary reason you are looking to repair it. Personally, I'd go with painted PVC, because after it is protected from UV light, it is less flexible (less pipe collapse) has a wider variety of fittings, and generally has a wider range of temperature distributions. I'm also more familiar with PVC, which might cloud my judgement. I'd love to hear from someone intimately familiar with ABS.

Both types of plastic are generally considered for low pressure applications, if you are having consistent freezing problems, neither pipe is meant to withstand routine freezing of water in-pipe.

PVC UVR is UV light resistant PVC. Buy it and paint it if you want a very long lasting PVC solution. Basically, you will have to worry about the (in my experience) natural enemies of PVC pipe before worrying about aging, that is careless yard crews, people vigorously digging, etc.