Patent ID: 7565065

Claim:
A fluid heater having: a casing configured by a case body formed by a tube member, and lid portions which are detachably attached to respective end portions of said case body to close the end portions; a heater which is passed through at least one of said lid portions to be placed in an interior of said case body; and fluid supplying/discharging portions for an inner space of said case body which are formed in at least two places of said lid portions, respectively; and wherein said tube member is made of a flexible synthetic resin, each of said lid portions is configured by: a lid body having a receiving port which receives a corresponding one of the end portions of said case body, and at least one sealing face which is disposed in said receiving port; a union nut which is externally screwable with a receiving port-side end portion of said lid body in a state where said union nut is externally fitted to the end portion of said case body; and at least one sealing portion which is formed by screwingly advancing said union nut to said lid body to press said case body from an outside, and by closely contacting the end portion of said case body with said sealing face of said lid body by the pressing function, a lead-out portion through which said heater is passed is formed in said lid body of at least one of said lid portions, and said fluid supplying/discharging portions are formed in said lid bodies as portions through which a fluid passing a flow path portion is introduced or discharged, said flow path portion being outside said heater in said casing; and each of said sealing portions is formed by close contact between: a sealing face configured by forming a tapered face in a position inner than an inlet of said receiving port, said tapered face having a diameter which is gradually increased toward an outer side in an axial direction of said lid body; and a projection end face formed by a tapered face which is formed in a tip end of a projection portion of an inner ring, said projection portion being projected from the end portion of said case body, said inner ring being pressingly inserted into the end portion of said case body to increase a diameter of the end portion into a mountain-like section shape.