Repair and reconstruction of engineering structures - Assessment and Refurbishment of Steel Structures - page 316

Figure 6.154 Connector pad-welded
onto the pipeline
Figure 6.155 The fittings to cut out the
holes
and the by-pass at the same time. The next step is to transfer the cutting machine to the
external connectors and begin drilling the holes to install the stopple pluggs, which close
the flow in the pipeline. From then on the pipeline is plugged in two places and the
damaged section can be replaced (Figure 6.153(c)). After the repair work has been
finished the stopple pluggs are dismantled and the flow through the repaired pipeline
section can be restored. Then the by-pass pipeline and the plate gates can also be
dismantled (Figure 6.153(d)). This is possible because of the design of plugs of the Lock-
O-Ring type. On the collars there are also regular pipe plate stoppers with seals.