Patent ID: 8141911

Claim:
A pipe connection joint comprising: a flange joined to a connection object having a passage for a flow of fluid and a pipe joining hole penetratingly formed on the flange, the pipe joining hole having a linear slant portion widening toward the connection object; and a pipe bent in an L-shape and inserted into the pipe joining hole of the flange, the pipe having a pipe-expanded portion expandably formed on the pipe along the linear slant portion to thereby be closely joined to the linear slant portion of the pipe joining hole, the pipe being connected to the passage of the connection object in a state where a sealing member is seated on an outer surface of one end portion of the pipe; the pipe joining hole further comprises: an arc-shaped portion formed on one end portion thereof with a radius in such a way as to be in contact with an inwardly-curved surface portion of the pipe; and the linear slant portion extending from the arc-shaped portion to another end portion thereof and being, inclined at a angle in such a way as to be in contact with the pipe-expanded portion of the pipe, and wherein a plurality of stepped portions of a depth are formed on an inner circumferential surface of the pipe joining hole so that an exterior circumferential surface of the pipe-expanded portion filled in and compressively joined to the inside of the stepped portion to thereby enhance the joining strength between the pipe and the flange.