Are car heating pipes used as insulation pipes?

I don’t know what insulation you want to use it for.

Logically speaking, it is possible. The car heater water pipe uses the cooling water of the car engine. As long as the car runs for a period of time, the water temperature will rise. This is where the warm air comes from. But if the engine does not operation, the water temperature will drop. It won’t be able to keep warm