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 recirculation pump.

"Basically, the bladder inversion head allows you to shoot a calibration tube through your liner without losing air pressure," says Jim Gould, R&D and production manager for Perma-Liner Industries. "You don't have to disconnect anything; you leave it hooked up to the bladder and inversion head. You can cook with hot water using the Maverick II or steam with The Stinger, if you wanted it fast. I prefer the steam. It's much faster (than water) and you don't need large quantities of water, depending on the length of your shot."

The inversion heads enable contractors to shoot liner into a pipeline with active infiltration. "You don't want that water to get in between the liner and the host pipe because you won't have a perfectly round liner," Gould says. The inversion heads can be used in any size pipe, but are most commonly used in 4- and 6-inch lines. Average cook time is less than half an hour.

On the market for less than a year, the redesigned heads were the result of needing to hold pressure on the liner before applying the pressure cap, Gould says. "A pinch clamp wouldn't work because with the steam you have a relief end on your calibration tube that allows steam to pass through, so you would immediately lose pressure if you aren't constantly adding air or steam. And as far as the Maverick II version with hot water, we have a tube that goes through all the way to the opposite end of the calibration tube. You couldn't pinch it off because the tube was in the way. You needed the bladder sealed off so you can put your cap on and start your steam or hot water." 866/336-2568; www.perma-liner.com