ForeverSink is rated to a maximum of 50 psi. We have that tubing extruded for us and give them the spec we need.The 50 psi is based on the idea that 80 feet of depth is rare for us to place equipment in.Also you have the water (outside) force pushing back against the tubing a lot of times at the same pressure. Most of the pumps we use are 30-40 psi rated pistons.As far as having it out of the water an airing it up I would think much over 50-75psi (out of the water) could get ugly as it should start to enlarge. Its a great question that has not come up.
