Originals or re-engineered?
By Anthony Brough
Not all re-engineered parts provide equal or better performance or life
to the original components they are replacing, so a careful evaluation
should become part of the purchase consideration.
The use of re-engineered parts versus
original components is a somewhat
controversial topic. It is well known that
gas turbine OEM’s invest heavily in human
resources, development tools, development
capital and research when introducing a
new gas turbine model with precisely
designed components that will ensure
the operational objectives of the new
or uprated turbine model.
Over the course of the last 10-15 years
these developments have led to many
valuable improvements such as ultra-low
combustion systems, 3D aero-profiling
of airfoils, advanced metallurgy, new
coating technologies, and advanced cooling methodologies. These advancements, have yielded significant improvements in gas turbine operational performance:
■ Lower emissions
■ Higher output power
■ Increased thermal efficiencies
■ Faster start-up and loading times
■ Sometimes extended outage intervals.
However, these improvements have come at a cost. Component replacement, particularly hot-section components can be expensive, driven by increased manufacturing cost and the need to recover investment capital. Independent service providers over the past 10-15 years have become proficient at duplicating, and sometimes improving the design and manufacture of these components. The development, advancement, and utilization of imaging, coordinate measuring machine (CMM), and metallurgical analysis tools have led to a virtual explosion
of non-OEM component development.
What are re-engineered parts?
Components designed and manufactured by independent or third parties, intended as a direct replacement for OEM designed and manufactured parts are called re-engineered parts (REPs). Often, the re-engineered part may have metallurgical
or other changes that address a shortcoming of the OEM part or some other improvement. Other changes may be intended to reduce cost or to avoid conflict with intellectual property rights. There may be other names for these types of components, but for this article we will use the REP nomenclature.
REPs are “form, fit, and functionally” equivalent to OEM parts, or may have certain upgrades or changes implemented to improve on either the performance or the durability of the OEM equivalent. However, not all REP components provide equal or better performance or life, so a careful evaluation should become part of the purchase consideration.
OEM vs. REP
When making comparisons it is easy to conclude that one entity is “better” than the other, but there are true positive and negative aspects to both participants. The decision to utilize an OEM vs. an REP component in a gas turbine comes down to
Cost: OEM components are almost always costlier to purchase than an REP component. Typically, an REP can be purchased at 50-80% of the OEM list price. From the OEM perspective, they have invested a great deal of money and effort into designing their gas turbine (and the associated components) and they rely on both the original turbine sale and the aftermarket annuity to recover their investment. Recovering this substantial investment is an understandable expectation, however during many years, annual OEM price escalations can often lead to individual component prices that simply contradict the “market comparable” expectations. As gas turbine models approach “legacy status” (which we define as 20 years and older), operators and other service providers often turn to REPs as a cost-effective alternative.
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