GB1368665A - Pipes - Google Patents

Abstract

1368665 Insulating pipes GRANGES HEDLUND AB 18 Aug 1972 [27 Aug 1971] 38676/72 Headings F2P and F2G A pipe comprises a number of interjoined pipe sections 10, 12 each of which consists of at least one inner pipe length arranged within an insulating casing 20 and maintained in space relationship therewith by distance pieces 26, the insulating casing being made from a rigid load absorbing body of cellular structure, the outer surface of this casing comprising a watertight layer 16. The watertight layer is securely connected with the casing and preferably consists of fibre-reinforced thermosetting resin. The insulating casing is constructed of coarse particulate material of particle size 5 to 50 mm., e.g. clinker held by a binding agent, e.g. cement or mortar. The insulating casing may be formed in a mould, the watertight layer being applied either by lining the mould or by winding on to the insulating casing after its removal from the mould. Where pipe lengths are joined together the inner pipes are welded as at 14, the insulating casing stopping short of the pipe ends, and a sleeve 34 of similar construction to the insulated casing is slid from the broken line position to the full line position. Sealing rings 44, 46 (or 58, 60, 62 or 64, Figs. 3, 4, not shown) are positioned between the sleeve 34 and insulated casing 20 and a muff 48 is shrink fitted at each end of the sleeve 34 on to the adjacent insulating casings. In another embodiment (Figs. 7 and 8, not shown) two half sleeves are applied around the inner pipe between the ends of the insulating casings and a jointing sleeve (70) is fitted over the outside. The ends of this sleeve are tapered outwards and fitted with sealing sleeves (74) of tapered cross-section.