Once again applying a logic that does not fit this. A cars coolant system is pressurized many atmosphere above sea level to raise the boiling point, this is not pressurized to such extremes. I addressed the 7 layer concept already, each layer takes into account for different issues, one being UV protection. If you are sooooo concerned about the scientific nature of the tubing and its abilities please call Shannon Plastics, as they are the manufacturer. I surely would not be calling up Grumman over an actuator that was made by BENDIX...
You are incorrect a radiator system sees temperatures in a normal operation 190-210 degrees range and pressurizations of many atmospheres above sea level, you may think 16lbs is nothing. It is apparent the lack of knowledge of such a basic automotive system and even worse the lack of knowledge of this PBR system.