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| The TesTex TS-2000 LFET Tube
Scanning system is based on the principles
of Low Frequency Electromagnetic Technique
(LFET). It is designed to quickly scan Boiler
Waterwall, Reheater, & Superheater Tubing
found in Utility Boilers as well as larger
Industrial Boilers. Inspections using LFET
are conducted from the Tube O.D. (outer
diameter). In many cases, Economizer tubing
can also be scanned. PLEASE NOTE: The TS-2000
can scan magnetic and non-magnetic metals. |
| The TS-2000 System uses scanners
that have (8) or (16) pick-up sensors equally
spaced within the concave surface of the
actual scanner. The scanners have a concave
surface to match the given O.D. of the tube
to be scanned. Generally, a 120-degree span
of the given tube is being scanned as the
scanner moves along the length of tubing.
This allows for a real time, 3-D, color
graphic display of the section of tube being
scanned. Because these discreet pick-up
sensors are very small (usually a few millimeters
in diameter), they have higher resolution
and greater detection capabilities for smaller
flaws such as pitting. |
| The TS-2000 System detects
flaws such as Corrosion Cells & Hydrogen
Damage, Caustic and Phosphate Gouging, Oxygen
Pitting, Departure from Nucleate Boiler,
ID Pitting, Corrosion, and Erosion. Flaws
can be on the tube I.D. or O.D. Cracking
is also detectable and the detection of
cracking can be optimized through modified
pick-up coil configurations. |
| Other methods for the inspection
of tubing components in Boilers are UT (Thickness
as well as A-Scan, B-Scan, C-Scan, Time
of Flight Diffraction, and Phased Array),
RT or X-Ray, and EMAT (ElectroMagnetic Acoustic
Transducer). For UT and EMAT, Boiler tubing
needs to be sandblasted, or spot prepared
for individual discreet UT thickness readings.
Also, neither UT or EMAT provide rapid coverage
of the tube to be scanned; UT merely does
spot checks while EMAT only scans a strip
of tubing less that ¼” wide.
RT/X-Ray has obvious deficiencies such as
getting coverage as well as restraints to
conducting testing while other outage activities
are taking place. |
| For Natural Gas or Oil burning
boilers, the TesTex TS-2000 does not require
any surface preparation. In Coal burning
boilers, a quality high-pressure water blast
usually suffices for the TS-2000 to be effective.
This is primarily because the TesTex LFET
is a non-contact method; the actual scanner
surface containing the sensors does not
actually make contact with the tubing. Because
the TS-2000 operates as a very low frequency
(usually 10Hz or less), any non-magnetic
deposits do not affect the passage of the
electromagnetic field; even Iron Oxide does
not affect the signal path, as Iron Oxide
is a very “puffy” material compared
to the base metal being tested. |
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Real time, 3-D, color
graphic display; data can be saved
for further data analysis or permanent
record archiving |
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Rapidly gets 120 degree
coverage on tubes being tested in
a single pass of the scanner |
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Special Scanners made
that only have ½” stand-off
therefore being able to scan Reheater
tubing |
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No surface preparation
needed for Gas or Oil burning boilers |
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Quality high-pressure
water blasting usually sufficient
for Coal burning boilers |
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Straight sections and
bends inspected |
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2,000-3,000 linear feet
of tubing can be scanned in a 10-12
hour shift with one inspection team |
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Scanning can be conducted
from Skyclimbers or Hard Scaffolding |
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Low Signal to Noise
ratio |
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- Scanner sizes from
½” OD tubing up to maximum
tubing OD |
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