摘要 |
<p>A three-way valve (1) for a pig pipeline comprises a main tubular section (2), designed to allow a pig to pass through it, and a secondary tubular section (5) connected at right angles to this main section opposite an opening (7) determined by the intersection of the internal cylindrical wall of the main section with a surface (33) in the shape of a portion of a sphere facing the secondary tubular section. A movable element for selectively closing off the opening comprises, located off-centre with respect to a control shaft (20) placed on the side of this secondary tubular section, a flag (30) shaped in such a way as to close off this opening (7) completely by hugging this surface in the shape of a portion of a sphere, thereby completing, in this region, the cylindrical internal surface of the main tubular section. …<IMAGE>… </p> |