Abstract: Apparatus and device for testing within a metal pipe are described. The apparatus includes an exciter for generating an electromagnetic (EM) field for exciting a wall of the metal pipe; an extendable and retractable sensor assembly comprising a plurality of sensor bars arranged in an angled manner with respect to an axis of the pipe for sensing residue EM field on a wall of the pipe; a plurality of guide wheel assemblies for supporting and moving the apparatus along the axis of the pipe; and a control unit for recording sensed data from the sensor assembly.

Abstract: A system and method are disclosed for protecting bearings operating in dirty environments. The system may include a reservoir of lubricant, a bearing, and a regulator. The bearing may border on both the dirty environment and the reservoir. Accordingly, the bearing may be exposed to the solid particles carried by the fluid within the environment, as well as the lubricant of the reservoir. The regulator may ensure that the pressure within the reservoir is greater than the pressure of the dirty environment. Due to the higher pressure within the reservoir, the bearing may be preferentially filled with lubricant rather than dirty fluid from the environment.