Drain pipe plug device

Abstract

The drain pipe plug device for drain testing includes an elongated elastomeric, flexible, resilient, hollow, generally cylindrical tube which has a central passageway running its length and in communication with a rear portion bearing an inlet and front portion bearing an outlet. These two portions are joined to a middle portion of the same external diameter as the front and rear portions. The inlet is fitted with a connector adapted to receive water and air hoses. The outlet is fitted with a pressure relief valve. The sidewall thickness of the device uniformly tapers down from the front portion through the middle and rear portions. The front tube portion collapses first after the device has been radially expanded under fluid pressure, so as to prevent backflow of fluid through the device. The front and rear ends of the device are tapered down externally to facilitate sliding the device through drain pipes. The front and rear portions bear external spaced transverse ribs while the middle portion has an external grid pattern of spaced longitudinal and transverse ribs. In one embodiment, the longitudinal ribs extend through the front and rear portions but are slightly lower in height than said transverse ribs to facilitate flexing and sliding of the latter for improved sealing.

Dependencies are inferred from the claim text.