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Excerpt:
API 5L pipe manufactured with the Electric
Resistance Weld (ERW) or High Frequency Induction (HFIW) welding
processes offers considerable cost saving to the end user in place of
similar seamless or Submerged Arc Welded (SAW) pipe. Historically, such
pipe has never been fully trusted for full application by the oil and
gas industry due to catastrophic failures in the field. No universally
recognized industry standard exists for qualification of manufacturers
of ERW/HFI pipe, and there is no robust standard for promoting a high
level of quality and reliability of such a product. Saudi Aramco learned
first hand the impact of such lack of product reliability with 10 field
failures during hydrostatic testing of a newly constructed pipeline. The
experience resulted in significant project delay and cost over run.
As a result of this experience, Saudi Aramco eventually developed an
extremely comprehensive qualification and manufacturing specification
for such pipe. The specification incorporates a statistically proven
qualification procedure and a rigorous manufacturing process control
regimen to maintain extremely high quality and mechanical properties of
the ERW/HFI weld seam. At the same time, Saudi Aramco developed a
proprietary computer program for the collection, manipulation, and
reporting of qualification and production test data. Currently four
such pipe manufacturers in the world are approved to manufacture pipe in
accordance with the new specifications. Because of the greatly increased
reliability of pipe produced to the new specification, Saudi Aramco has
been able to consider the use of ERW/HFI manufactured pipe in
applications which were considered more critical. As projects begin to
utilize this new approach Saudi Aramco will be able to realize as much
as $100/ton savings in the future. |