Thermal Insulation
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6.1 Pre-Insulation Checks
Visually inspect the heating cable and components for
correct installation and damage. Damaged cable must
be replaced.
Perform insulation resistance testing, known as a
Megger test (refer to Section 9), prior to covering
the pipe with thermal insulation.
6.2 Insulation Installation Hints
• Insulation must be properly installed and kept dry.
• Check insulation type and thickness against the
design specification.
• To minimize potential heating cable damage,
insulate as soon as possible after tracing.
• Check that pipe fittings, wall penetrations, and other
irregular areas have been completely insulated.
• When installing cladding, be sure drills, screws, and
sharp edges do not damage the heating cable.
• To weatherproof the insulation, seal around all
fixtures that extend through the cladding. Check
around valve stems, support brackets, and
thermostat capillaries.
6.3 Marking
Apply “Electric Traced” labels on outside of the cladding
at 10-foot intervals on alternate sides to indicate
presence of electric cables.
Other labels, which identify the location of splices, tees,
and end connections installed beneath the thermal
insulation, are supplied with those components and
must also be used.
6.4 Post-Insulation Testing
After the insulation is complete, perform an insulation
resistance test on each circuit to confirm that the cable
has not been damaged (refer to Section 9).
WARNING: Use only fire-resistant insulation,
such as fiberglass, mineral wool, or calcium silicate.