Joint flange

(canceled)

A joint flange comprising a first clamping piece and a second clamping piece, wherein the first clamping piece and the second clamping piece assume a C-shape to form clamp openings at a center of inner rim of the clamping pieces, one end of the first clamping piece and the second clamping piece is provided respectively with a latching part and a positioning part, whereas the other end of the first clamping piece and the second clamping piece is provided respectively with a pivot part,

• by locking together the pivot parts, the first clamping piece and the second clamping piece are opened and closed using the pivot parts as pivots, and when the joint flange is to be used, the first clamping piece and the second clamping piece, each having an outer circumferential wall, are clamped opposite to each other on a rim of an expansion fitting to constitute the joint flange by joining the latching parts with the positioning parts,
• a rim of a pipe contacting the rim of the expansion fitting with the outer circumferential wall of the first and second clamping pieces also contacting the rim of the pipe to form a space between the joint flange and the rim of the pipe which space receives the rim of the expansion fitting.

(canceled)