Temperature Sensitive Ardweeny

Yes, it was a temperature sensitive Ardweeny that was causing me trouble with the Acid Pump.  I couldn't tell which part it was that was failing, so I just programmed a new one and put it in place.  Pump is working fine now.  I'll use the temperature sensitive one in some application inside the house where the temperature extremes are not as high; it should work fine there.  Glad I put the Ardweeny in an IC socket, it made replacement easy.

The new fittings and pump head are also working fine.  I'll have to give them some time to see if they start having problems and the temperatures are low so the chemical reactions are retarded and the problem might not come up until summer.  In the meantime, I have gotten some check valves and adapters to try out.  I went to  US Plastics and browsed through their site and found something that may be good as a replacement, but haven't tried them yet.  The new check valves have a metal spring in them; that could be a nasty problem to overcome.  Almost all metals react with HCL, and some of them do it really fast.  I have one of them already in place as the injection valve into the two inch pipe plumbing the pool.  In this case, the spring is exposed to the pool water most of the time with only limited exposure to the acid.  In this instance, it works fine, but the outlook is not as optimistic for something that is exposed to straight acid 24 x 7.  Here's a picture of the candidate replacement parts:

Notice that everything is plastic except the spring, I wonder if I can find Kynar or Teflon springs somewhere.