Abstract: A surface of a hydrophobic microporous thermal insulation material is coated by first heating the surface of the microporous thermal insulation material so as to provide a hydrophilic surface layer on the hydrophobic material. Subsequently, a water-based coating, such as a water-based silicate adhesive, is applied to the hydrophilic surface layer of the hydrophobic material. An abrasive-and/or impact-resistant cover, such as a glass fibre cloth, may be applied to the coating.

Abstract: A wound coil which is rotating about its axis is cut and severed against a stationary member by moving a rotatable cutting blade incorporating a circular cutting edge towards the rotating coil and the stationary member such that the cutting blade rotates about the axis of the arcuate cutting edge against the wound coil, becomes inserted between adjacent turns of the wound coil and cuts the wire forming the coil against the support. Once the coil has been cut, the cutting blade is moved away from the coil. A roller is provided to limit movement of the cutting edge of the cutting blade in the axial direction of the coil.

Abstract: An insulated duct, for example for electric cables, comprises first and second co-operable members forming a duct therebetween and toggle clips to secure the first and second members together such that the first and second members are urged towards each other. Each member comprises a base of thermal insulation material and at least one wall portion of thermal insulation material extending from the base of at least one of the members. An external skin is provided on the thermal insulation material, and an internal lining is provided on the thermal insulation material. The thermal insulation material, the external skin and the internal lining of the first member are dimensioned substantially to abut against the thermal insulation material, the external skin and the internal lining respectively of the second member.

Abstract: A microporous thermal insulation material is formed from an intimate mixture of a dry particulate microporous material and reinforcing glass filaments. The glass constituting the glass filaments contains not more than 1 per cent by weight Na.sub.2 O and preferably has the following composition:______________________________________ SiO.sub.2 50-100 percent by weight Al.sub.2 O.sub.3 up to 25 percent by weight B.sub.2 O.sub.3 up to 8 percent by weight MgO up to 10 percent by weight CaO up to 21 percent by weight Na.sub.2 O up to 1 percent by weight K.sub.2 O up to 2 percent by weight Fe.sub.2 O.sub.3 up to 1 percent by weight F.sub.2 up to 1 percent by weight.

Abstract: A close wound coil is formed by a sequence of steps including supplying a wire to be formed into a coil onto a rotating mandrel by means of a guide wheel and urging the wire against the mandrel by means of a pressure wheel so as to form a coil. The formed coil is allowed to free itself from engagement with the mandrel from a point immediately following that at which the wire is urged against the mandrel by the pressure wheel to the end of the mandrel so that the formed coil, although carried by the mandrel, is unrestrained relative to the mandrel.

Abstract: Vibrations that arise during the winding of a coil of wire onto a rotating mandrel are damped by surrounding the coil with a tube such that the tube is spaced from the coil and by supplying fluid to the tube. The tube extends in the axial direction of the coil along at least a part of its length and, due to the spacing between the tube and the coil, conducts fluid such as water in a confined manner towards at least one end of the tube and releases the fluid from the end of the tube, for example in a region of the coil adjacent to and/or remote from the winding of the coil.

Abstract: Apparatus for testing material for thermally insulating pipes comprises a closed loop of pipe in a square configuration with an electric heater mounted coaxially within it. Thermocouples are attached to the pipe from the inside, and they and the heater are accessible via removable caps at the corners of the square. The pipe is suspended from a support framework by rods of low thermal conductivity welded to the inside corners of the square. The insulating material is applied to the pipe, and additional thermocouples fixed to its exterior. The heater is energized and the steady-state temperatures inside and outside the insulating material are measured. The configuration of the apparatus enables corrections for non-uniformity of heat loss and leakage through the rods to be readily made. Thus thermal conductivity values accurately representative of the performance of the insulating material in actual operation can be derived from the temperature measurements.