Page 57 - Pipeline Pigging Technology

Pipeline Pigging Technology

Construction - "the way something is put together" or "the act of
putting something together";
Maintenance - "the work of keeping something in proper condition";
Move - "to change in position from one point to another";
Relocate - "to establish in a new place".

Now comes the term Rehabilitation, which means "to restore".
The purpose of this is to show that since the pipeline safety regulations do
not speak to rehabilitation, per se, there is a lot of room for 'creative
interpretation' regarding which regulations apply to what activities. This
presentation is not an attempt to offer an interpretation of the regulations, but
to highlight some points that I consider worth giving careful consideration to
when planning and executing rehabilitation work. With more emphasis
being placed on regulatory inspection and enforcement, thorough planning
now could pay dividends in the future.

REHABILITATION

A rehab job is basically a large maintenance project with varying degrees
of complexity that can involve several aspects of the regulations, including
materials, design, general construction, welding, corrosion control, testing
and operations.
There are several reasons for deciding to rehabilitate a pipeline; however,
the most common is external corrosion due to coating failure. The decision
to rehabilitate is usually determined by several factors, including failure
history, excessive maintenance and cathodic protection costs, and, in some
cases, the presence of stress-corrosion cracking. The primary motivating
factor behind this decision is to maintain and operate a safe pipeline.
When planning rehabilitation work, no two jobs will be exactly alike or
present the same set of circumstances. Therefore, in order to stress the
importance and complexity of complying with the present Federal Pipeline
Safety Standards, I have taken two projects that represent probably the most
common types of work and will explore where each type method could be
impacted by the regulations. The first (Method 1) is the rehab of a line that is
left in place in the ditch and remains in service. The second, (Method 2) is
when the line is taken out of service, evacuated, removed from the ditch and
placed on skids along side the ditch.

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