In personal testing, our Black Solar Tubing was subject to different temperatures well above boiling (264 degrees F), under pressure (70 psi), and below freezing repeatedly for 5 years without damage. When the pressure was released during the test at 264 F, the absorption backing (at that time the backing was made of black plastic bags) melted due to the sudden convection released. The water popped and cracked (believed to be steam) as it moved through the pipe. The exit pipe insulating wrap had an odor of melting as the heated water moved through the pipe. In another test, our Black Solar Tubing was allowed to face the sun, with 70 psi of water pressured applied, while the temperature reached over 300 F before the outer portion of the pipe failed, but it still held the water without immediate rupture. Months later, the exposed pipe failed, allowing water leakage. In another test with a larger collector unit, the enclosed collector was allowed to stagnate in the middle of a clear February day. The exit pipe was connected to a short garden hose with a metal rubber coated sprayer. The inlet hose was a short garden hose connected to a water outlet at 70 psi with an input water temperature of approximately 50 F. The outside ambient temperature was approximately 68 F. With an infrared thermometer pointing to the tip of the rubber covered metal sprayer, the pressure was released. Immediately, the temperature jumped from 73 F to 140 F. Within 3 seconds, the water temperature increased from 140 to 206. Then the steam came, melted the water hose from the sprayer handle, scalded my arm from my wrist to elbow and caused the observers to run to a safer distance. For the next minute, steam exited the hose and caused it to violently swing back and forth. The grass root system where the steam exited from the garden hose was killed, and a bare spot developed well into the summer months. And there was absolutely no damage to our Black Solar Tubing.