| 摘要 |
A wiper for wiping liquids from the interior walls of various tubular members, such as drill pipe, tubing, casing or internal upset pipe is disclosed which is particularly useful in drilling and workover as the tubular members are withdrawn from a well bore. Features of the wiper include the ability to readily and easily pass through and wipe liquids from restricted passages or bores such as internal upset pipe, means for centralizing the wiper in the passages or bore for efficient wiping, pressure equalization for equalizing pressures within the wiper with outside pressures encountered within the well bore, made from materials which will not create an explosive condition in use, and ease of manufacture, assembly and disassembly, so that the wiper can be manufactured easily, readily and inexpensively, and repairs and replacement of wear prone parts can be readily and inexpensively made. Other features and advantages are disclosed.
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