Question: How long after sleeve installation do I have to wait before I can backfill?
Answer: Assuming we are talking about WPCT, WPC100M, WPC120, TPS or any number of our other two layer heat shrinkable sleeve systems; the answer is simple. You must wait until the sleeve has cooled to ambient temperatures. If necessary, you can even quench the sleeve (after installation) with water to cool it faster.
That is one of the great things about shrink sleeves. After it is installed and inspected, you don't have to worry about it anymore. No chance of anything happening to it (unless someone drives their truck into the pipeline and their bumper scrapes a hole in the sleeve....which I have seen before!)