JPS56111525A - Manufacture of heat insulated pipe possessing curved part - Google Patents

Abstract

PURPOSE: To manufacture the titled heat insulated pipe in which an expanded heat insulating material is uniformly filled up in the space between an inner pipe and outer pipe, by applying the heat insulating material to the wall surface of the inner and outer pipes, by inserting a guiding member into the clearance between these heat insulating materials, applying bending work to the pipe, and heating the pipe after removing the guiding member in order to expand the heat insulating material.

CONSTITUTION: A heat insulating material 14, causing expansion by heating, such a material mainly comprising fluorite, etc., for example, is applied to the outer surface of the inner pipe 4 to a thickness forming a clearance equivalent to the thickness of the guiding member 8 against the inner surface of the outer pipe 2, within the space 3 formed between the inner pipe 4 and the outer pipe 2. The guiding member 8 is inserted into the clearance between the heat insulating material 14 and the inner surface of the outer pipe 2 to a depth nearby the bending part 10. Next, this double pipe 6 under this condition is fixed at the part suitably distant from the part 10, and is subjected to the bending work by pressing the part 10 with the press 12. Then, the guiding member 8 is withdrawn from the curved pipe 6 which is heated thereon in order to expand the heat insulating material 14 so as to fill up the space 3.

COPYRIGHT: (C)1981,JPO&Japio