Do NFPA and UL provide guidance for installation and use of heat tracing in automatic sprinkler systems for areas exposed to freezing?

by Nils Deacon, Manager, Inspections and Rating Services

NFPA 13, the automatic sprinkler system Standard, allows for heat tracing systems to protect areas of sprinkler piping exposed to low temperatures.

Heat tracing systems have been used in industrial applications for many years. This includes freeze protection for water piping, and process regulation where maintenance of a specific temperature for the liquid is necessary.

The method involves securely wrapping or attaching electric cables along the length of piping. An electric heating element provides a constant level of warmth to keep the water or other fluid at the desired temperature. Thermal insulation, either on the electric cable or the piping itself, is another important element in this system.

For protection of sprinkler piping, heat tracing is permitted using listed equipment. The listing is from UL 515A which is the certification for heat tracing for automatic sprinkler system components.

The UL Standard includes a monitored connection to the power supply with an alarm system, in the event of a loss of power. Performance tests are included to be sure the system maintains the desired temperature, and to monitor high or low water temperature, loss of continuity of the cable, and monitoring system failure.

DISCLAIMER: This information reflects the interpretation of MSO, Inc. with regard to NFPA Standards and Codes and other code sources. It does not represent these codes’ official position on the items discussed.