What precautions should be taken when sizing heating cables on non-metallic piping?

Apr 23, 2018

Pipe tracing on non-metallic pipes such as PVC, PEX or CPVC that are used for water supply, waste and storm piping should be sized according to the diameter of the pipe, the lowest ambient temperature it will operate at, and the amount of insulation installed to keep it from freezing. Heating cables on plastic pipes should never exceed 5 watts per foot (15 watts per metre) to avoid damaging these pipes due to excessive heat from the cable. On larger pipes where you may need in excess of 5 watts per foot, install two or more runs of heating cable. The cables should have one run of aluminum high temperature tape installed directly on the pipe and then the cable is attached with another layer of tape over the cable and the first layer of aluminum tape. This aids in heat distribution. Pipe tracing charts are available from Britech. You can reach us at www.britech.ca and we will send you a catalogue.