Supply mains between the risers and cooler/freezer areas can be highly susceptible to corrosion.
There are two factors that limit corrosion in coolers and freezers:
- In order to have corrosion liquid water must be present. It is quite rare to have corrosion in freezers. Ice blocks can form in the lines because the compressor adds water, but the lack of liquid water in the piping prevents oxygen corrosion.
- All chemical reaction rates slow with reductions in temperature. Every 18-degree reduction in temperature cuts the chemical reaction in half. At cooler and freezer temperatures the rate of oxygen corrosion on the piping is very, very slow.
While corrosion rates in coolers and freezers are very low, supply mains between the risers and cooler/freezer areas located in conditioned spaces can be highly susceptible to corrosion.