I was looking for info about heat tape, a recurring topic of conversation here, and found a couple of pages of manufacturer’s info about Frostex heat tape. Good info about how much tape and insulation is needed on different sizes and types of water lines.
Forgot to add the URL for the second document from the manufacturer of Frostex. Good info.
This is the heat tape that you can buy in bulk and cut to size. Then you add a plug assembly. The newest version of the plug assembly has built-in ground fault circuit protection.