Testing has shown that this design meets or exceeds SMACNA's Class 3 for leakage (-20 inches wg to +20 inches wg). The new fittings are available as round elbows, couplings, reducers, and taps in diameters of three through 24 inches. Galvanized steel construction meets SMACNA's +10-inch wg positive pressure standard, and are compatible with all of McGill AirFlow's round, single-wall duct types.
Custer said a decision was made to offer this product as an option on duct up to 24 inches, but "we didn't think it was suited to larger diameter pipe." McGill has worked with a couple of contractors in Ohio to launch the product and fine tune it. Several Publix grocery stores in Florida also are using it. "It lends itself to grocery stores and other light commercial jobs such as strip malls," Custer said. McGill produces the Uni-Gasket ductwork at seven manufacturing plants around the country, and has it available at its 42 sales offices and warehouses through its "Duct Express" quick delivery service.