High-pressure tapping apparatus

摘要

The proposed high-pressure tapping apparatus for tapping an opening into an existing pipeline that is under internal pressure comprises a tubular body (12) being provided with means (28) on one end for attachment to a pipeline, a boring bar (22) having a rotatable feed screw (24) therein by which the boring bar (22) is axially positioned, and a pressure responsive valve of a control mechanism (54) actuated by differential pressure between the interior of a pipeline and the interior of the tapping machine body casing (14) to control hydraulic pressure inside the tapping machine body (12) to thereby counterbalance the hydraulic force applied to the boring bar (22).