Abstract: The invention proposes a device, e.g. an inspection pig, for inspecting conduits made from ferromagnetic materials, such as pipelines, for faults, cracks, corrosion or the like, comprising at least one pulling element, a supporting structure of variable circumference, disposed on the pulling element and comprising substantially radially disposed supporting arms each of which is pivotable about axes disposed perpendicular to the longitudinal central axis of the pulling element, and several permanent magnets disposed at the circumference of the supporting structure for generating a magnetic field, and with sensors. For strengthening or weakening the magnetic field generated by the permanent magnets in dependence on the circumference of the supporting structure or in dependence on the lateral separation between the permanent magnets, the permanent magnets are associated with further magnets having a magnetic field which can be varied in direction or strength.

Abstract: A device (1) for passing through pipes in the form of a pig (1) moving through the pipe and guided on the inner wall thereof has at least one pig body (16) and support elements (8a) on the outer periphery thereof for guidance within the pipe as well as drive elements (10a, 10b) in the form of collars for transport in the pipe. The device is distinguished by improved entrance into the pipe conduit in that at least one of the collars (10a, 10b) can be radially expanded.

Abstract: In order to facilitate introduction of an inspection pig through an introductory conduit having a smaller diameter and into a pipeline of large diameter and transporting a fluid, in particular gas or oil, the invention proposes a device for inspection of pipes having sensors disposed about an outer periphery thereof having radially expandable inspection units (6, 7), wherein, in particular, a front and a rear inspection unit (6, 7) having sensors (15; 15′) displaced with respect to each other in a peripheral sense can be moved axially towards each other.

Abstract: An apparatus for analyzing anomalies such as cracks, corrosion and the like in a pipeline wall is provided. The apparatus is formed of one or more cylindrical body sections. A series of magnetizing units are mounted around the circumference of the body. Each magnetizing unit is formed by a backing bar, brushes which are capable of inducing a magnetic field, sensors which are capable of measuring magnetic flux leakage caused by anomalies in the wall and bearing wheels which reduce wear on the brushes and sensors. The backing bar is flexibly mounted on the body so that it can follow the contour of the pipeline wall as the apparatus moves through the pipeline. The backing bar has steel-containing brushes mounted on either end atop magnets of opposite polarities such that a magnetic field may be transmitted to the pipeline wall. The brushes are ideally formed by steel cables encased in polyurethane and mounted on a steel shell. The sensors are mounted in the central part of the backing bar, between the brushes.