Sure, but it will deteriorate over time. We have successfully buried it to cushion water PVC pipe from rocks.
nashua 555 hvac flexfix tape. I've used it for years and never had it fall off.
I've had this on hot water base board pipe and it did not melt and I have my furance set at 185 degrees
If it is exposed to the sun I doubt it would last long.
It definitely will protect against ambient heat temperature or radiant heat from the sun. The exterior of the foam may heat up but does not transfer through the insulation.
The polyethylene is water tight but when you cut the slit to install the insulation that creates a small area for moisture to penetrate. If that is a concern Home Depot has an insulated tape that you can over wrap the insulated foam with.
foil tape. Nashua Tape 1.89 in. x 50 yd. 322 Multi-Purpose HVAC Foil Tape #100030120. rub it good.
The R-value of this pipe insulation is 3.1.
I would not do that until I had a clear explanation from the heat tape manufacturer. In general, the foam pipe insulation will retain heat which could cause other issues with the heat tape.