Heat insulating pipe

• Main Authors: NOJIRI; AKIO, HORIGUCH; MASAO, KOREEDA; TOSHIO
• Format: Patent
• Language: English
• Published: 10.07.1984
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BLASTING; CHEMISTRY; COMPOSITIONS BASED THEREON; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL PROCESSES OF COMPOUNDING; HEATING; JOINTS OR FITTINGS FOR PIPES; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIGHTING; MAKING GRANULES OR PREFORMS; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PIPES; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THEIR PREPARATION OR CHEMICAL WORKING-UP; THERMAL INSULATION IN GENERAL; TRANSPORTING; WEAPONS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A heat insulating pipe has a foamed heat insulating layer on its outer circumferential face in which the heat insulating layer has an expansion ratio of at least 4 and is of a three-layered structure consisting of a middle foamed layer and lower and upper foamed layers formed at both sides of the middle foamed layer. The cells of the middle foamed layer are relatively large. The cells of the upper foamed layer and the lower foamed layer are relatively small. The shapes of the cells of the middle foamed layer are such that, for the average cell diameter ( mu 1) measured in the radial direction of the pipe and the average cell diameter ( mu 2) measured in the axial direction of the pipe, the relation of mu 1/ mu 2=0.3-0.9 holds.