| 摘要 |
<p>The piston of a pump down wells scraper tool comprises an elastomeric sphere compressible between clamping discs on a centre tube to achieve adjustment of the outside diameter to fit different tubing sizes. A ball and socket joint connects the piston to the scraper section which has radially expendable, spring urged helical blades for scraping the bore of the tubing as the tool is pumped along.</p> |
