When I got into the carwash industry 11 years ago, I was told that the GRAY foot valves were more chemical resistant than the BLUE ones, and to just use the GRAY ones for all my chemicals (degreaser, presoak,
soap, wax), to simplify my inventory. However, I too have been noticing that my GRAY foot valves don't last as long as they used to.
According to the
Kleen-Rite catalog the GRAY foot valves uses an EPDM seal (for
soap &wax), while the BLUE foot valve uses a Viton seal (for white wall, butyl, alkalis). I did some Google research and found that the Viton seals are made by Dupont and designed to be very chemical resistant. When I spoke to
Kleen-rite yesterday, they confirmed my findings and told me that the BLUE foot valves are MORE chemical resistant than the GRAY ones. When I asked if they were from China, he didn't know, but said they purchased them from a company in Ohio. Based on this information, I ordered some BLUE foot valves with the Viton seal, and am planning to use them exclusively from now on.