PHASED ARRAY ULTRASONIC

INSPECTIONS FOR REFINERY

APPLICATIONS

INTEGRITY NDT Ltd. SOLUTIONS

Prepared by: Gorkem Bayten

APPLICATIONS

� Detection of Stress-Oriented Hydrogen Induced Cracking or

SOHIC

� Detection of HTHA (High temperature hydrogen attack)

� Corrosion mapping in nozzles

� PA&TOFD imaging and sizing of welds

� Inspection of Bolting for Cracks and Corrosion

� Inspection of Complex Geometry

� Heavy Wall Vessel Crack Detection and Sizing

� Heavy Wall Power Piping Inspection to ASME B31.1 and

B31.3

� ASME CC 2235 PA Inspection for the Replacement of

Radiography

HYDROGEN INDUCED CRACKING (HIC)

� Set up consists of a -30 +30o S-scan at 0.5o resolution.

� The A-scan display was switched between Auto Track Mode and Normal to best characterize the indication.

HYDROGEN INDUCED CRACKING (HIC)

� As the probe is moved left and

right and back and forth the

side step cracking can be

tracked in real depth display

allowing the operator to easily

determine severity, depth, and determine severity, depth, and

characterization of the HIC

� The two images show actual

HIC side step cracking and

inclusions and spot laminations

that are not considered

detrimental to the vessel

HYDROGEN INDUCED CRACKING (HIC)

� The corrosion mapping vender has to make a decision. Is it

corrosion? Is it a lamination from the pre-service?, is it

spot inclusions from the pre-service? or is it Hydrogen

Induced Cracking that could rupture at any time?

HIGH TEMPERATURE HYDROGEN ATTACK

� HTHA in the petrochemical plants is caused when the

hydrogen from the stream seeps into carbon and low alloy

steels at high temperatures.

� Hydrogen reacts with the carbides in the steel,

decarburizing the steel and forming methane gas bubbles

at the grain boundaries with no loss of thickness. at the grain boundaries with no loss of thickness.

� The methane gas bubbles grow with time and result in

micro cracking.

� The combination of micro cracking and decarburization

reduces the fracture toughness of steels and leads to

major failures

HIGH TEMPERATURE HYDROGEN ATTACK

� Damage originally measured by changes in velocity.

� New NDE approach uses PA’s to detect increased

backscatter (right) over clean material (left).

NOZZLE EROSION-CORROSION

Beam swept 0-70 L-Waves

SmoothEnd Surface

70 Degree

PA Probe32 Element, 10MHz

Waves

Bottom Surface

Corner

0 DegreeLaw

70 DegreeLaw

NOZZLE EROSION-CORROSION

10MHz PA Probe

178 mm test block

Bevel End Step end

NOZZLE EROSION-CORROSION

Bevel End Zoomed

WELD INSPECTION

� Select arrays to give adequate coverage; need to ensure

HAZ and weld zone covered

� Scan weld in parallel linear motion, or move weld past

stationary arrays -> much faster.

Left: Conventional UT Right: Phased Array

WELD INSPECTION

� Typical weld inspection using combined electronic and linear scanning.

� ASME-type 45o and 60o shear wave & TOFD inspections; ~10x faster than raster scanning.

� Need to cover weld, HAZ, any position errors => significant amount of coverage.amount of coverage.

Works well for wide gap welds.

WELD INSPECTION

� This image shows weld profile superimposed on “top,

side,end” and waveform view.

INSPECTION OF BOLTING

� One zone was created for the body (non-threaded) area and

one zone for the threaded area on the near side. The only

difference between the set up for the two zones were

adjustments to the range and gain to account for the longer

sound path.

� Moving the probe back and forth and side to side, a full � Moving the probe back and forth and side to side, a full

volumetric inspection can be achieved from either side.

Care must be taken to maneuver the probe around the

retaining pin hole to ensure complete coverage. The 15

degree sector scan allows you to steer the beam under this

obstruction.

INSPECTION OF BOLTING

INSPECTION OF BOLTING

� Corroded bolt inspected in place showing complete thread

loss from 24-33mm

INSPECTION OF COMPLEX GEOMETRY

� In the example below there is an acceptable length of non

penetration that cannot exceed 10mm. This can be easily

measured by using the delta between the two signals from

the sector scan.

HEAVY WALL VESSEL INSPECTION

� Sector scan image at over 100mm in depth detecting ID

connected thermal fatigue crack

HEAVY WALL POWER PIPING INSPECTION

� Replaces radiography and radiation hazard for increased

productivity.

� Provides detailed defect depth, height and length sizing

� Computer based software utilizing weld overlays, advanced

focal low programming, and custom displays

� 15 minute per weld on 100mm + 10-20 inch diameter � 15 minute per weld on 100mm + 10-20 inch diameter

power piping

� One side and two sided inspections for pipe-pipe, pipe-elbow,

pipe to flange, etc.

� Utilizes standard ASME type calibration blocks

� Typical instrumentation is TD HandyScan 32:128 and

Omniscan 32:128 with and Tomoview 2.7 for computer

based acquisition

HEAVY WALL POWER PIPING INSPECTION

� Full calibration of all A-scans for sensitivity, TOF, TCG\DAC

to meet ASME standards

� Typical ASME calibration standard using similar material

and specified SDH

HEAVY WALL POWER PIPING INSPECTION

� 100mm+ full volumetric inspection

� Lack of fusion easily characterized, sized, and recorded for

code accept/reject

ASME CC 2235

� Integrity I-Scan magnetic scanner does not require power or

complex motion controllers

� Combines TOFD and Phased Array for detailed defect

detection and sizing

� Less than 3 hours of up front engineering to include creation

of scan plan, inspection strategy, calibration, and equipment of scan plan, inspection strategy, calibration, and equipment

mobilization

� Using existing ID/OD notch and SDH type calibration

standards typical of ASME Sec VIII

� No power required. 100% battery operated inspection using

TD Handy Scan 32:128 with PA and TOFD accessories

� Can be used on material thickness from 12mm to 100MM+

ASME CC 2235

� Scan plan required 1 probe on each side of the weld utilizing

linear scans for the upper 1/3, middle 1/3, and lower 1/3

+ 2 TOFD channels

� All-scans acquired simultaneously and analyzed in real time

during the inspection

� Weld overlay allows easy placement of defects in weld for � Weld overlay allows easy placement of defects in weld for

analysis and documentation

� 200+ A-scans acquired, all are programmed to be the direct

equivalent of a 5MHz 20mm diameter convention UT probe

calibrated for sensitivity, TOF, and TCG\DAC.

ASME CC 2235

ASME CC 2235

� Primary inspection view displays 2 TOFD channels and a C-

scan merge of all focal laws on all channels. The merge view

is the sum of all A-scans allowing analysis of 200+ A-scans

simultaneously.

� A weld with no defects can be analyzed in less than 1 minute� A weld with no defects can be analyzed in less than 1 minute

ASME CC 2235

ASME CC 2235

� When a defect is detected the operator changes to the sizing

layout to measure the defects depth and height utilizing the

weld overlays, data projection tools, amplitude drop sizing

tools and measurement cursors

� Every A-scan on every channel is recorded and can be

analyzed independently. The electronic raster below on the

upstream Midwall channel can be electronically rastered in

and out from the weld in analysis mode and is the direct

equivalent of a single channel conventional raster scan.

ASME CC 2235

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