Boilers and coil-type heaters that utilize organic or synthetic fluids as a heat-transfer media shall be designed, constructed and installed in accordance with the ASME code. Piping for organic or synthetic fluids used as a heat-transfer media and subject to temperatures in excess of 250°F shall be installed in accordance with ASME B31.1.
Wis. Admin. Code Department of Safety and Professional Services SPS 341.48
See sections SPS 341.41(1) and (2) for requirements relating to registering these installations with the Department.