| 摘要 |
<p>The invention relates to a gas passing joint, and to a process and a device for making the same, meant for performing joinings from the street network of natural gas distribution towards the industrial or domestic consummers. According to the invention, in the first performing version, the passing joint is provided with a joint nipple (1) endowed inside with some circular channels (a) and a polyethylene tube (2) which is crimped to the nipple (1), by means of an intermediary piece (3). In another embodiment, the passing joint is provided with a metallic sleeve (4) assembled together with a pipe (5), a polyethylene tube being crimped inside the sleeve (4) by means of an intermediary piece (7). The process for making the joint consists in introducing a hollow metallic piece inside a plastic tube, afterwards the both marks are introduced into a metallic pipe. At the lower end of the cylindrical piece, there is created a force circularly distributed and axially applied, force which, by displacing the application point, gradually produces the increase of the diameter of the hollow piece on the entire length thereof. As a consequence of the created pressure, the tube material penetrates in the channels inside the pipe, by stiffening and sealing the assembly. The device is provided with a puller screw (8), with a tray (9) and a cylindrical nut (10) which may displace a taper bushing (12).</p> |
