Marden Susco has developed a mobile butterfly valve testing unit, the Barbee Model H Valve Testing Unit, that provides on-site hydrostatic leak testing in a self-contained, dedicated unit. It performs testing on butterfly valves up to 36 in. and Class 150 and 250. Hydro tests can be regulated from 50 to 500 psi. The unit can also be used to test rubber seated gate valves.