Freeze Protection of Piping
Freeze protection of water piping located outside or exposed to cold temperatures requires planning and adherence to proper specifications. Thermal insulation alone, even when applied correctly and in the proper thickness, does not necessarily prevent freezing. All electrical heat tracing manufacturers provide a specific heat loss calculation chart for selecting the proper heat trace wattage, based on the pipe diameter and insulation thickness. It is important to use the correct wattage rating from these charts.
The most common wattages used for freeze protection of water piping are 3, 5, and 8 watts per foot. In some instances, 10 and 15 watts per foot may be required. Small-diameter piping (3 inches or less), hung horizontally, is more susceptible to freezing than vertical piping of the same diameter, however, both should be treated equally for the protection of the entire system. Flanges, valves, and instrumentation all must have the electric tracing looped or installed properly to eliminate cold spots or gaps in the system. Environmental factors such as wind speed, minimum ambient temperature, and the location of the piping can require a different level of protection (e.g. piping located on a roof vs. buried in the ground).
Fortunately, many regions of the Mid-Atlantic where Waco operates, do not experience long extended periods of below-freezing temperatures. However, a polar vortex situation like the one that occurred around Christmas in 2022 did not take long to cause serious problems for many businesses and factories.
What are the piping systems that are most susceptible to freezing?
- Hydronic water piping on HVAC units and cooling towers
- Makeup water piping and exposed plumbing
- Wastewater piping at Water Treatment Plants
- Water piping at Pump Stations or Industrial facilities
The main type of electric tracing for freeze protection is called self-regulating (SR) and is designed to operate with demand, ﬂuctuating or increasing the wattage as the temperature drops. Another type of electric tracing is Constant Wattage (CW), which is commonly used to maintain a constant specified temperature in water or liquids of a process system. Heat tracing can be powered by any of the voltages commonly found in commercial or industrial facilities (120, 208, 240, and 277) but must be ordered for the specific voltage available.
Insulation contractors like Waco, Inc. are very capable of eﬀectively installing SR electric heat tracing and providing the proper insulation and weather barrier jacketing systems. It is a complete package that clients find more cost-effective than getting separate bids for heat tracing and insulation from diﬀerent contractors. A qualified electrician is required to make the final connection to the power source on any system involved. Waco works with several electrical contractors to ensure that the tracing is properly installed and that junction boxes and thermostats are located in such a way to reduce the lengths of conduit needed to power them. Sometimes heat tracing may need to be located in a hazardous environment, which would require Class 1, 2, or 3 explosion-proof electrical enclosures. Waco can provide systems with additional ground fault protection, in addition to heat trace cable manufactured with corrosion-resistant material or non-sparking, non-metallic design.
Any thermal insulation system must be properly installed so that the heat tracing can perform as designed. Adequate protection from the weather is critical. Waco has decades of experience with heat-trace systems, and we continually train our workforce on proper installation techniques. You can be assured that we will provide a complete system that performs and protects, reducing your worries during the winter months and throughout the year. Don’t wait until cold weather arrives. Contact Waco for your next heat tracing project.