Hydrocarbon Processing - April 2022 - 21

Special Focus Maintenance and Reliability
A. ALZAHRANI, Saudi Aramco, Abqaiq Plants, Saudi Arabia
A new era of turbomachinery reverse engineering
Engineering is all about solving problems
with efficient solutions by designing
and building various technologies and
techniques.
In the oil and gas segment and hydrocarbon
processing industry (HPI), one of the
main challenges is how to maintain aging
facilities with old equipment that have no
existing original equipment manufacturer
(OEM) and spare parts. To overcome this
challenge, the author's company approved
reverse engineering as a new methodology
to repair obsolete equipment and ensure
the availability of their spare parts.
Reverse engineering is the process by
which a mechanical component can be
modeled by evaluating its mechanical
and performance characteristics, and its
physical dimensions measured to produce
a duplicate or an enhanced version of the
component. In addition, utilization of reverse
engineering methodology is mainly
considered in the following cases:
* The OEM no longer exists.
* The product performance and
features require improvement.
* The OEM is quoting an
inflated price.
* The OEM is offering an
unacceptable delivery time.
Problem identification. The story of
reverse engineering at Aramco's Abqaiq
Plants began when a single-stage steam
turbine that drives a critical crude oil
transfer pump was reported for a sudden
increase in vibration values while the turbine
was running on full load speed, as
shown in FIG. 1.
By studying equipment parameter
trends, the vibration analysis showed signs
of rotor unbalance, which was later confirmed
by performing an internal inspection
of the turbine's rotor wheel by a stateof-the-art
industrial borescope camera.
The equipment was sent to the company's
mechanical services shop in Dhahran
for a complete overhaul. After dismantling
the equipment, the need to perform
a complete re-blading activity to repair
the rotor wheel was confirmed. Because
the steam turbine was no longer produced
and the manufacturer was no longer in the
market, the limited availability of spares
was one of the main challenges in bringing
the equipment back to service.
During the spare parts material sourcing
activities, a new rotor was offered
by one of the main active steam turbine
manufacturers with a cost of $350,000,
which is equivalent to 70% of the cost of
a new steam turbine. Furthermore, the
delivery lead time of the new rotor was
approximately 1 yr, which would result in
increased equipment downtime, affecting
overall plant availability.
Success story. In line with the author's
company's efforts toward investing in new
state-of-the-art technologies to enhance
maintenance and reliability performance,
Abqaiq Plants piloted the reverse engineering
technology capitalizing on local
resources and capabilities in collaboration
with the company's central engineering
and mechanical services shop. This action
was taken to overcome critical equipment
outages and minimize repair cost and time.
The reverse engineering process began
with a 3D scan that was completed inhouse
using 7-axis scanning machines to
capture the geometry of all parts in-house
at the reverse engineering center.
The second stage was computer-aided
design (CAD) modeling performed using
the collected data during the 3D scanning
stage. From this, the ultimate 3D CAD
models for all required mechanical parts
were developed and prepared by a highly
advanced modeling software.
After that, the engineering work stage
was started and involved significant R&D
efforts. This project included more than
20 trials and experiments with different
materials, geometries and heat treatment
conditions to ensure the quality and mechanical
integrity of newly engineered
parts (FIG. 2). As a result, the strength of
blades was doubled by upgrading their
material composition.
The project was completed during the
manufacturing stage when local capabilities
were utilized for the blades fabrication
in collaboration with one of the leading
companies in the reverse engineering
works in Saudi Arabia.
After
this collaboration with Saudi
Aramco departments, the steam turbine
was returned to Abqaiq Plants, installed
FIG. 1. Vibration parameter.
Hydrocarbon Processing | APRIL 2022 21
Hydrocarbon Processing - April 2022

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