Patent ID: 8789562
Filing Date: 2014-07-29
Classification: F16L,G01M

Abstract:
1. A flexible tube for transporting a cryogenic fluid, comprising: a flexible corrugated metallic inner tube; a reinforcement layer disposed on the outer periphery of the corrugated metallic inner tube, formed by alternate winding of a reinforcement tape, and configured to reduce deformation of the corrugated metallic inner tube in an axial direction; a first heat insulating layer disposed on the outer periphery of the reinforcement layer; a second heat insulating layer disposed on the outer periphery of the first heat insulating layer; an optical fiber temperature sensor disposed between the first heat insulating layer and the second heat insulating layer, and being wound spirally at a predetermined pitch; and a waterproof layer disposed on the outer periphery of the second heat insulating layer, wherein the second heat insulating layer is configured to be impermeable to water and disposed on the outer periphery of the optical fiber temperature sensor, the first heat insulating layer is configured to have a greater liquid permeability than the second insulating layer such that the cryogenic fluid preferentially permeates the first heat insulating layer instead of the second heat insulating layer, when there is no presence of a cryogenic fluid leak in the flexible tube, the cryogenic fluid is thermally insulated by the first heat insulating layer and the optical fiber temperature sensor is not affected by the temperature of the cryogenic fluid, and in response to a cryogenic fluid leak, the cryogenic fluid permeates the first heat insulating layer which is detected by the optical fiber temperature sensor.