Abstract: Apparatus for electromagnetically testing pipeline walls of steel or the like ferromagnetic material which is equipped, for example with a magnetizing coil for leakage-flux measurements, can be extended for ultrasonic measurement which is inductively excited and inductively measured with regard to the travel time as far as a reflecting surface and back, in the disposed in one or more of the pole regions there is a high-frequency current coil for the transmission and/or reception of steep-edged waves which are inductively coupled at the wall of the pipeline. The associated method starts from a stationary magnetic field in which high-frequency current pulses are produced in order to initiate vibrations in the pipe wall through induced currents. The travel time of these vibrations to a reflecting point and back can be measured in order to obtain an indication regarding the intact thickness of the pipe wall.

Abstract: A pipeline inspection apparatus is disclosed for the detection of corrosion pit type defects, employing one or more ultrasonic transducers to produce a parallel beam for direction toward the pipe wall from inside a pipe, with a sufficiently large beam width to permit comparison of time displayed signal components in defect depth determination, with the signal propagating through a gaseous medium. An additional embodiment combines the same with photographic apparatus.

Abstract: A corrosion probe is disclosed which includes two permanent bar magnets in side-by-side relation, with opposite magnetic orientation and with poles of opposite polarity adjacent a sensing end of the probe, a sensing coil being disposed around the magnets adjacent the sensing end. The probe is disclosed in use in a pipe inspection pig for controlling operation of a camera.

Abstract: During the drying of long-distance pipelines, in a development of vacuum drying--possibly in combination with compressed-air drying, go-devils and/or alcohol drying--a flooding is provided which precludes the recondensation of the water in the residual water vapor. For this purpose a movement of drawn-off water vapor and following scavenging gas in the same direction is ensured and the scavenging gas is throttled in its input of travelling speed so that no condensation occurs even in the boundary region to the departing water vapor.

Abstract: The invention relates to total elimination of aqueous deposits in pipelines intended for transporting gaseous fluids, such as a natural gas. The method involves sending, by a nozzle at an end of at least one compressed air ejector, connected with the pipeline, a pressurized driving fluid (for example, under 4 to 8 bars) into a pipeline which aspirates and entrains the gaseous fluid (air+water vapor), the mixture of fluids then being discharged at the other end of the ejector. In practice, multistage ejectors for example three ejectors in series, are used. According to a variant of the method, the step of putting gas which is to be transported into the pipeline is done while the vacuum is maintained in the ejector or ejectors so as always to be outside the limits of flammability of this gas. The method is particularly suitable for drying natural gas pipelines and then putting the pipelines under pressure.

Abstract: A tube cleaning material for cleaning the inside of a tube is adapted to be passed through such a tube by means of a back pressure. The tube cleaning material includes a cylindrical body provided with at least one, and, preferably, a plurality of spiral grooves formed in its peripheral surface. The grooves extend and run in the same direction from the front to the rear of the cylindrical body. The edges of the groove are brought close to each other, when the material is pressed into the tube, so as to prevent wrinkles from appearing on the surface of the material. In addition, the grooves allow the back pressure creating medium to go ahead of the body to moisten the sticking contaminants on the tube. This facilitates the removal of contaminants especially when the medium is water. The body is rendered rotatable by the fluid medium. In one embodiment of the invention the grooves of one side communicate with the grooves on the other side of the body by a bore diametrically extending through the body.