For use in potable hot water systems. Antimicrobial Liner/ASHRAE 188 Anti-Legionella Fixed diaphragm construction. Constructed to ASME Section VIII, Division 1. Maximum Operating Temperature: 200� F. ST-5C through ST-20VC 150 and 175 PSI features deep drawn steel construction. ST-30VC through ST-42VC 150 PSI features deep drawn steel construction.