Bi-Directional Leak Detection System with Full Observability

Leak detection apparatus for deployment in a pipe. The apparatus includes a carrier disposed for motion along the pipe and a detector connected to move with the carrier in an axial direction. The detector comprises a drum mounted for rotation about pitch and yaw axes. A flexible material is mounted on, and extends from, the drum and at least two sensors responsive to drum rotation are provided. The flexible material will be drawn into contact with a wall of the pipe at a leak location, thereby producing a torque on the drum, causing the drum to rotate, and the at least two sensors to generate signals from which leak location is determined.