Page 63 - Pipeline Pigging Technology

Pipeline Pigging Technology

Materials

Any materials or components, whether new or used, that are added to the
existing system have to meet certain requirements. This includes both the
selection and qualification.

Design

Pipe - this covers internal and external pressures and loads.
Components - involve all valves, fittings, fabricated assemblies, etc., that
are subject to the system pressure.

Welding

Any welding done on a pipeline has to meet the applicable welding
requirements. This includes the welding of clamps and sleeves.

Construction

Construction regulations cover a broad range of activities. The regulations
are directed to new construction, but also pipe replacement and relocation
that is part of rehabilitation work. Also, anything that applies to a new line
would certainly be a valid guideline for the rehabilitation of a line.
Some key areas are inspection of materials and work, repair of pipe,
installation of pipe in the ditch, backfill and cover over the buried pipeline.
In addition, various construction and as-built records are required.

Testing requirements

This is an area that certainly requires careful consideration. The general
requirement sections for testing under both the natural-gas and hazardous-
liquid regulations have not been definitively interpreted. In the case of
Method 2, there would be no question as to the requirements for hydrostatic
testing under the requirements of either the gas or liquid regulations. Also,
with increased emphasis on protecting the environment, the handling of the
test water is very crucial.

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