Heating Cables + Heating Tapes
Because knitting prevents the tape from tensile stress when stretched, this type of heaters are commonly used on flexible tubes.
Heating cables are mainly used on pipes, fittings and tanks.
Heating tapes are bundled, fine stranded resistance wire, 35 – 37 gauge, covered with several layers of high temperature yarn. The insulated resistance wire is then knitted like a serpentine into a flat tape. This knitting allows for cushioning and expansion during heating in all directions, therefore virtually eliminating thermal growth. Knitting allows dense distribution of wire per square inch and therefore can withstand watt densities up to 15 watts per square inch.
Heating cables are used for pipe freeze protection.