The Stinger steam-cure and Maverick II hot water-cure bladder inversion heads from Perma-Liner Industries feature an internal silicon bladder and air connection port between the silicon bladder and the calibration tube. The design enables the installer to invert the calibration tube and hold pressure on the liner while removing the bladder inversion head from the Perma-Liner inverter. Without the silicon bladder and air introduced through the air connection port, the liner and calibration tube would collapse and possibly cause a failure when re-inflated. The Maverick II hot-water boiler also has a
