DISC-TYPE CLEANING BIDIRECTIONAL PISTON Russian patent published in 2001 - IPC

FIELD: cleaning inner surface of pipelines, possibly at separating successively pumped different oil products, at displacing air or removing water out of cavity of pipeline during hydraulic testing. SUBSTANCE: piston includes tubular body closed at both ends and having at both ends set of discs, each set is tightened to pack between flange secured to body and pressure ring. Pack includes discs of polyurethane or other flexible strong elastomer. Pack includes one or more guiding discs with diameter equal to inner diameter of pipeline or less than it by some value; one or more sealing discs with diameter exceeding inner diameter of pipeline by tightness value and intermediate discs for separating guiding discs arranged near ends of body and sealing discs. Guiding and sealing discs have edges adjoining to pipeline with sharpening angle being less than 90 degrees and formed in periphery of discs at both sides by means of annular recesses. Said recesses have cross section in the form of non-isosceles triangle. Sealing discs have sharpening angle of edges inversely proportional to tightness value. EFFECT: enhanced efficiency of cleaning, enlarged using range, increased wear resistance of cleaning members. 2 cl, 7 dwg