The line to
Mark Lacey, Operations
Director, HTC Ltd, UK,
gives an
overview of the essential activities
required when pre-commisioning
cross-country pipelines.
W
hether constructing a new pipeline for oil, gas or water use, revalidating or up-rating existing
pipelines, the only viable, practical method of ensuring the pipeline is free of defects is to carry
out a hydrostatic pressure test.
During the pipeline planning and design stage the requirements and effects of hydrotesting
should be a major consideration – it is impractical to design and construct a large diameter cross-country
pipeline where there is no water source to supply the hydrotest medium. Similarly, process pipework that
cannot be drained of water will present significant drying problems during pre-commissioning.
In preparation for pre-commissioning operations, a hydrotest plan should be developed to assess and
confirm the number and lengths of test sections based on topography practical location for test section
tie-in points, available water extraction and disposal locations and access to the spread for the installation of
equipment.
Elevations, static heads and test pressures for individual sections must be assessed to ensure that sections
are not under or over tested for the pipe material, in compliance with the appropriate specification.
Roles, responsibilities and competencies must be defined, contact details and
emergency procedure documents listed. The requirement for statutory notification
to the local authorities and landowners of the intention to test must be identified for
each section and a programme of works developed.
COMPLETION
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