In 2019, Underwriters Laboratories (UL) issued the first certification for trace heating equipment for use with a fire sprinkler system, including the installation on sprinkler branch lines. This certification complements the requirements in the NFPA 13, Standard for Installation of Sprinkler Systems. Certification for heat tracing systems for fire sprinklers provides a practical option for protecting fire sprinkler piping from freezing in cold environments.
NFPA 13 Requirements
NFPA 13 allows for some trace heating systems – or heat tracing, as referenced in NFPA 13 – to be used on wet pipe sprinkler systems. Only heat tracing systems that are specifically listed, certified for this purpose are allowed. NFPA 13 requires that trace heating be specifically certified for this type of installation.
Certification Heat Tracing Systems for Fire Sprinklers Applications
Self-regulating heat tracing has been very well accepted and is routinely used in many commercial applications such as freeze protection of building plumbing systems, grease waste and fuel line viscosity maintenance, deicing of roofs and gutters, frost heave protection, and other applications. UL has a long history and experience in certifying trace heating equipment for many of these applications. However, these certifications do not address the unique concerns associated with the use of a sprinkler system providing fire safety.
It is important to verify that the equipment used on a fire sprinkler system is listed, certified for this specific use. A trace heating system intended for fire sprinkler applications is typically composed of several elements including the trace heating cable, components and accessories, and associated controls.
UL’s certification of a heat tracing systems for fire sprinklers includes elements from IEEE 515.1 that are relevant to sprinkler systems along with additional requirements described in UL 515A, Outline of Investigation for Electrical Resistance Trace Heating and Associated Controls for Use In Sprinkler and Standpipe Systems.
The requirements associated with the UL certification of trace heating systems are comprehensive and include:
- Performance testing to confirm systems maintain water temperatures high enough to prevent freezing but not too hot to pose a safety hazard.
- Provisions for permanent connection to a power supply and for compatibility with and connection to a fire alarm system.
- Confirmation that instructions are available from the manufacturer to properly design and install the trace heating system so that it will provide the necessary freeze protection without obstructing the water discharge pattern from a sprinkler head.
Read more information about specify nVent Raychem products approved by UL for fire sprinkler applications:
- nVent RAYCHEM 465 controller for Heat Tracing of Fire Protection Piping
- nVent RAYCHEM XL-Trace Edge Self-Regulating Heating Cable