Abstract: In a subterranean heat insulated pipe system as laid with angellike bendings between straight pipe lengths, i.e. a district heating pipe underneath a street angle, the conventional bending elements are substituted by pipe elements joined so as to form a bending run of a relatively large bending radius, which, depending of the pipe size, has a minimum value, by which the pipe bending by itself and by interaction with the earth is able to take up the expansion and contraction forces, which are created in the pipe in response to temperature changes therein. The said minimum value has been found to be so low that in many instances it is hereby possible to avoid the sharp bending elements with their associated heavy problems due to expansion effects.

Abstract: For mounting a protective sleeve of plastic over a joint between prefabricated heat insulated pipes, typically subterranean district heating pipes, an axially split plastic sleeve is inserted laterally over the joint so as to bridge the opposed ends of outer protective plastic tubes of the joined pipes. A plastic welding strip provided with a number of embedded parallel heating wires, is placed along and over the relevant annular joint with its opposed ends located spaced from each other adjacent the axial split of the sleeve. The ends of the strip are provided with terminals for parallel connection of the embedded wires, and the wires are electrically heated to weld together the welding strip and the two plastic tube ends. The axial split is then scaled by a similar welding strip.

Abstract: In a dual component packing of the type consisting of a flexible bag, which contains the single liquid components in respective separate compartments, from which they may be brought together into a common mixing compartment by exterior manipulation, a mixing stick is mounted inside the packing so as to be seizable at one end by squeezing together the bag sheet material thereabout, whereafter the free end of the mixing stick by exterior manipulation can be moved around in the mixing compartment for effectively stirring and mixing the combined liquid components. Exterior pressure manipulations on the bag itself will be superfluous, and for this reason a packing of a simple flat bag type may be bottomwise designed so as to assume a cup shaped form when placed on a substantially planar support surface, whereby an effective mixing stirring by means of the said mixing stick is achievable.

Abstract: A measuring system for localizing a defect spot along a wire or along an insulated pipe having incorporated a wire in its insulation, comprising a pulse generator transmitting to one end of the wire consecutive trains of electric pulses, these pulses in each train being of steadily increasing or decreasing duration, an associated detector receiver for receiving through said wire end pulses reflected from said spot and designed so as to produce a detector signal in response to reception of a reflected pulse front substantially concurrently with the termination of the transmission of the pulse to which said pulse front belongs, and indicator means operable to identify each of the individual pulses in response to occurrence of said detector signal, whereby the duration of the pulse thus identified will be indicative of its running time to and from the defect pulse reflecting spot and therewith be indicative of the distance from the wire end to the spot.