GB1302463A - - Google Patents

Abstract

1302463 Insulated and fire-proof pipe T TARUKAWA 11 Jan 1971 [9 Jan 1970 2 Feb 1970] 1232/71 Heading F2P In a fire-resisting pipe, an outer casing 1 of inorganic fire-resisting mortar is spaced from a plastics inner pipe 2a by means 6 which permits some deformation of the outer pipe relative to the inner pipe. As shown, the means 6 may comprise stud or longitudinal rib members 4 formed on the inner pipe, or projections (7) (Fig. 4, not shown) integral with the outer casing 1. Alternatively, the spaced relationship of the pipe and casing may be maintained by a circumferentially extending step (5) (Fig. 3, not shown) on the pipe (2b) or by a series of wedges (10) (Fig. 5, not shown) inserted in opposite recesses (9) in the casing and pipe. In a further embodiment, longitudinal ribs (4a) (Figs. 9, 10) integral with the inner pipe (2e) engage the inner suface of the outer casing (1c) (Fig. 8, not shown) to produce grooves (12) as the pipe is inserted into the casing before the mortar material of the latter has fully hardened and contracted. In other embodiments, foam material may be injected to wholly or partly fill the pipecasing space or a tape, foam strip or cloth of cotton, nylon or asbestos may be wound about the pipe before applying a fire-proof outer casing of mortar. Elbows and junctions may also be produced by the methods described.