Last year we purchased a new home that included a in-ground pool. The pool was put in 20 years ago and I assume that the pump, filter and heater are all from the same era also. We ran the pool last year and everything worked OK until right at the end of the year the pump started getting really noisy and hot. So this winter I did some research and purchased an Ecopump and some parts to repair the existing filter as the base was broken because the equipment had just been sitting on boards which had moved over time cracking the sand filters base.
Fast forward to now I have a concrete pad done and just about everything complete except for the plumbing and the gas line to the heater. I am up sizing all of the plumbing that I can to 2". When I removed the old plumbing there was a short flexible piece of plumbing between 2 fittings that was between the pump and the filter. I assume this was for vibration reduction at the filter. I think this may have been a homemade piece by the original installers because I have yet to find a glue together flexible fitting other than the expansion pieces that are used primarily for repairs and only give you an extension motion for movement. It looks like a piece of flexible piping (similar to a pool vacuum hose) glued to 2 slip couplings.
Now for my question. Is frost heaving not an issue between the pump pad and the lines that run down underground to the pool? I know in the electrical world anytime you transfer above or below the frost line you need to put an expansion coupling in. Why is this not the same for pool plumbing? I originally wanted to use the same flexible type fitting that was on my system for all lines that went from the pad underground and also between the pump and the filter for vibration reduction. However I have not been able to locate anything similar which makes me think this is rather uncommon in the pool industry. The only thing that I have found that is even remotely similar or makes mention to my concern is the website below.
Here he mentions using the above flexible coupling as an option for vibration reduction. I purchased some of these couplings from lowes and was going to use them but they say they are not rated for pressure. I think the outcome would still be the same but I guess curiosity has gotten the best of me and now I just want to know why or how this is not an issue for pool plumbing. Frost is going to lift your pump pads and stress the pipes. Does the sand bed that they are layed in move enough to not crack the pipes? What happens if that freezes around the pipes?
Should I use the flexible rubber couplings linked above or am I asking for trouble? FYI Everything we are doing to this house is for the long term and to be as maintenance free as possible in the future.
Thanks for reading