TPT July 2015

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Technology News
48 July 2015
Pushing the limits of EDM inspection
SCAN Systems, a USA-based company
in the OCTG industry, offers “out-of-
the-box” on-location custom flaws and
artificial reference indicators to create
test standards for calibration. The
company has developed innovative
detection technology over the years that
has helped to overcome a number of
challenging industry obstacles.
EMI inspection machines have
traditionally relied upon slip rings to
transmit data from the longitudinal
rotating assembly back to the computer
for processing and interpretation. Worn
out or dirty slip rings can cause signal
loss, leading to less reliable data and
unseen indication of potential flaws.
Scan Systems applied some Silicon
Valley-style technology to the EMI
process and has incorporated wireless
capabilities into its M-Series EMI
inspection equipment, and removed
slip rings from data transmission. This
development utilises a Wi-Fi radio inside
a rotating head spinning up to 250rpm,
and overcomes the large amount of
magnetic flux created by the surrounding
large electromagnets. This benchmark
in the industry allows for improved data
accuracy and elimination of significant
data errors, and because the data is
digitised immediately at the sensor, any
signal noise from outside interference
is non-existent. “Your Internet went
wireless years ago. It’s about time that
EMI inspection equipment followed suit,”
said Matt Rutledge, general manager/VP
of Scan Systems.
Scan Systems’ ESP upgrade to its
M-Series line is the first EMI inspection
technology to use hall elements in the
longitudinal sensors, which enable
detection and repeatability on flaws up to
30° off the axis on the OD surface and
20° off axis ID surface (industry standard
is 7° to 10° off axis).
Additionally, by utilising hall elements,
the number of sensors can increase
from 16 to 64 channels of data for
better resolution and ability to detect
much smaller flaws than the limitations
of traditional PC coils. Scan Systems
claims to be the first in the world to bring
the ability to detect oblique flaws to EMI
inspection. Also, because of the use of
hall elements and the proprietary Digi-
Pro® processing software, if the operator
is set to detect at 30°, he will pick up
flaws between 0° and 30°, making for a
more accurate and precise pass.
Scan Systems has developed an EMI
system that can report the linear location
of a longitudinal flaw, the circumferential
location, and whether it is on the ID or
OD surface of the pipe. Historically, EMI
inspection equipment was limited to
reporting the linear location of a potential
flaw. Though a few manufacturers
would discriminate between ID and OD
indications, the reliability of the methods
utilised made the reporting less than
accurate. Through significant innovations
made in sensor technology, data
collection methods, and sophisticated
software algorithms, Scan Systems’
latest ESP upgrade to the Pitco™
M-Series EMI inspection now provides
the inspector with a level of accuracy
never seen before in EMI inspection
of OCTG material. This advancement
provides the circumferential location and
can report on multiple flaws on the same
plane and ID/OD location in degrees of
probability, saving valuable time during
the prove-up process.
One of the toughest tasks for an EMI
unit operator can be interpreting and
locating the signal from a pipe flaw.
Having an alternative view of the data
can be beneficial in determining a pipe’s
condition. Scan Systems developed a
display that not only makes it easy to
illustrate where pipe flaws are located
but also provides additional information
on the characteristics of the flaw.
Many OCTG MFL equipment
manufacturers claim their machines
detect flaws on 0.545" (13.84mm)
walls and greater during the inspection
process, but often these claims
ignore a key component of a quality
inspection – repeatability. This refers
to equipment’s hardware and software
capabilities to identify the signal given
by an imperfection or artificial reference
indicator and report those imperfections
at a similar amplitude consistently and
repeatedly.
API 5CT specifications require a
minimum of 20 per cent repeatability
on all inspection runs. Using advanced
signal processing algorithms combined
with proprietary sensors and cutting-
edge signal detection hardware, Scan
Systems’ Pitco M-Series with ESP
upgrade has dramatically improved the
ability to separate a flaw’s signal from
the background noise offering the best
S:N ratio on any given pipe.
While 0.4" (10mm) pipe wall thickness
has historically been the limit for existing
EMI/MFL inspection equipment, Scan
Systems’ Pitco M-Series with ESP
upgrade can reliably detect and repeat
on N5 ID notches up to 0.545" (13.84mm)
wall thickness and N10 ID notches up to
0.625" (15.875mm) walls. This ability to
accurately detect and repeat on these
types of indications is a remarkable
accomplishment.
Scan Systems Corp – USA
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The Pitco M-Series from Scan Systems