Lagged composite tube having cast iron tubular core - insulated with glass filled concrete material

摘要

Lagged composite tube consists of a tubular core of cast iron consisting of two cast iron tubes welded end to end and coaxially by their male extremities and presenting a housing at each of the free ends by means of which as sealed assembly is formed with a similar tube, a thick coating of heat insulating material and a thin sealing sheath covering the lagging. Specifically, the heat insulating material covers and follows internally the belled contour of the open ends of the core tube while the outside is cylindrical and smooth and stops right at the end of each belled portion. Pref. a polyurethane foam ring is fitted. The heat insulating material is under compression between the two belled ends and remains locked in position ensuring insulation around the jointed regions. The need for extra special insulation portions and for bulged tubes is avoided.