| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a simple-shaped pig which is a simple-shaped low-cost one which, unlike a conventional one, is free from a skirtlike scraper, is capable of being easily reused even when worn, damaged, or degraded after many-time use, and can be effectively used as a leader for the flow of a fluid through the pipe or for wiping or cleaning the passage of a pipe because it, like a conventional one, is excellent in scraping performances and running performances. SOLUTION: The bidirectional pig is one wherein the cylindrical surface of a pig body 1 has annular bent swells 2a and 2b formed at two specified parts distant from both ends by a specified distance and being distant from each other by a specified distance L1 ; the swells are concentric arcs in a cross section when viewed along the axis of the cylinder of the pig body 1 and are made from a high rubber elasticity member; the sides of the pig body 1 are simple-shaped pig heads of curved surfaces 4 which may be the same or different from each other in shape; and the body 1 can run in the two forward and backward directions.</p> |
