| 摘要 |
A tapping fitting for a pipe, preferably a plastic pipe, includes a rotatable blade assembly (3) threaded within a sleeve (4) non-rotatably received within a housing (2) such that rotation of the blade assembly (3) causes it to cut a cylindrical slug from the pipe to which the housing (2) is attached. The opposite faces of the sleeve (4) are exposed to the fluid pressure within the pipe thereby producing a balance of forces substantially eliminating transverse creep. In addition, the attaching section (22) of the fitting is formed with a bore (21) which is engageable by a sealing ring (35) received around the rotatable blade assembly (3) and which is of sufficient length to accommodate any axial creep, thereby enabling the blade assembly (3) also to serve as a valve. <IMAGE> |
