the present invention is a plug system having a plug for insertion into a pipeline , wherein the plug system is insertable via a fitting attached to the pipeline . a pre - drilled aperture of the pipeline positioned normal to the cylindrically - shaped pipeline may interfere with a pig traveling through the pipeline . in one embodiment , the plug includes two coaxial cylindrical portions . a first cylindrical portion has a diameter greater than the aperture diameter , while the second cylindrical portion has a diameter less than the aperture diameter . additionally the plug defines a hole that is oriented perpendicular to an axis of the cylindrical portions , wherein the diameter of the hole is approximately the size of inside diameter of the pipe . the plug has a retaining member to stabilize the plug system . when the plug is installed in the pipe it permit a pig to flow freely , thereby eliminating pigging hazards .