Patent ID: 6024134
Filing Date: 2000-02-15
Classification: F16L

Abstract:
A flexible hose, which comprises a main layer of a polyester-series thermoplastic polyurethane resin, a covering layer of a soft resin laminated on at least one surface of the main layer for forming a laminated tape, a hose wall formed by spirally winding the laminated tape and bonding the adjacent side edges of the covering layer each other, and a hard spiral reinforcement for reinforcing the hose wall and retaining the hose configuration, wherein the shrinkage ratio of the length of the hose in a normal condition (unloaded condition) is 25% or less relative to the original length of the hose as determined by measuring the original length and the length of the hose after the test which comprises subjecting the hose compressed in a longitudinal direction to ten heating/cooling-cycles successively, one cycle comprising a heating step for exposing the compressed hose to an atmosphere of 70.degree. C. for two hours and a cooling step for cooling the heat-treated hose at -20.degree. C. for two hours, followed by returning the temperature to an ordinary or room temperature and allowing the hose to stand for one hour.