Abstract: A drift is inserted into a first end of a first pipe and a first actuator is pressed against a second end of the first pipe. A valve in the first actuator is opened and a valve in a second actuator is closed. When a vacuum is turned on, suction is applied to the first actuator, drawing the drift through the first pipe. The drift is removed from the second end and inserted into a second end of a second pipe. The second actuator is pressed against a first end of the second pipe. The valve in the first actuator is closed, the valve in the second actuator is opened, and suction is applied, drawing the drift through the second pipe. The back-and-forth process is repeated for each of a number of pipes. If the drift encounters an obstruction, the pipe can be set aside for further inspection.

Abstract: A material feed system and method for conveying a metered quantity of lightweight, friable mesh fibers without minimal damage to the mesh fibers to concrete and like materials mixing tank. The material feed system including a hopper with a spiral fiber guide near the discharge and flexible blades for clearing fibers from the upper and lower surfaces of the spiral fiber guide. A drive assembly is included for rotating the hopper at a rotation rate adequate to move and agitate the mesh fibers to facilitate flow of the mesh fibers first outward against the side walls of the bin and then rapidly downward through the bin being guided by the spiral fiber guide.

Abstract: A hopper cylindrical about a vertical axis has an agitator with blades rotating near the bottom of the hopper, not only to agitate insulation but also to move it through a hopper outlet opening into an airlock having a horizontal shaft and radially spaced blades. The vertical shaft for the hopper agitator and the horizontal airlock shaft are aligned so that one may be driven from the other, as by miter gears. A motor and reduction gearing may drive the airlock shaft, through a chain and sprocket connection, or the motor and reduction gearing may drive the hopper agitator shaft through a coupling. The blades of the airlock rotor may be individually removable through the airlock inlet, as in order to replace flexible wipers. Each airlock blade may have a flange at an obtuse angle such as 150.degree. which is bolted to one side of the multisided shaft by a series of cap bolts.