Pipe pig and method of cleaning a pipe

摘要

A pipe pig for refinery heater tubes is disclosed. The pipe pig has arcuate cleaning elements which form an expandable circumference. Each of the arcuate cleaning elements has a scraping edge. A spring element biases the arcuate cleaning elements radially outward. The pipe pig may have structural components made from titanium alloys and arcuate cleaning elements made from carbon-carbon composites. A method for cleaning coking out of refinery heater tubes using the pipe pig is also disclosed.

主权项

1. A pipe pig with a pipe pig axis, the pipe pig comprising:
arcuate cleaning elements forming an expandable circumference, each of the arcuate cleaning elements having at least one scraping edge, in which the arcuate cleaning elements form linked pairs of arcuate cleaning elements connected by sliding pin joints, each sliding pin joint having a pin received to slide along a pin guide in a path perpendicular to a pin axis, the pin axis being parallel with the pipe pig axis; and a pressure responsive expander comprising a set of levers connected to the arcuate cleaning elements via yokes, the levers being spring biased to cause, in operation, the expandable circumference to expand and contract in response to varying pressure on the pressure responsive expander.