SE369221

1,230,055. Multitubular assembly. KABELUND METALLWERKE GUTEHOFFNUNGSHUTTE A.G. 3 Feb., 1970 [22 Feb., 1969], No. 5032/70. Heading F2P. A multitubular assembly for hydraulic or pneumatic transmission of measurements and control pulses comprises a plurality of tubes 1, bunched and covered with at least one metallic sheath 3, corrugated and made of an elongate strip bent and welded longitudinally. The corrugations may be spiral, and the helical space 4 formed inside the sheath may be used to circulate an isothermal fluid to obviate any errors arising out of the effect of external temperature fluctuations on the tubes 1. The said space may instead be filled with a controlledpressure fluid so that the working pressure of the fluid in the tubes may be increased. The arrangement may be modified to detect damage to any of the tubes 1 as indicated by a change in the monitored pressure of space 4, which may be used to actuate a switch-off means. There may be two concentric sheaths, and the outer sheath may be provided with an insulating layer, e.g. a layer of synthetic resin formed by extrusion, or alternatively, the space between the sheaths may contain an isothermal fluid, as a means of preventing temperature fluctuations in the tubes 1. The tubes may be of copper or aluminium and may themselves be corrugated to impart flexibility to the assembly and increased surface area for heat transfer. The assembly may include a strip 2 of synthetic resin or metal foil to bind the tubes together.