“Introduction to Guided Wave Inspection Theory and Technology”

Presented by: Nicholas Bublitz- Global Product

Support Specialist

Introduction •  Today’s inspection challenges are becoming more and more focused on productivity

combined with high quality results.

•  To complement an already strong pipeline product offering, Olympus has introduced a guided wave solution for corrosion and metal-loss detection on pipes.

•  The following slides present the basis of Guided Wave Theory and Technology and how this portable system maximizes the efficiency of a corrosion management program.

Introduction •  Guided Wave Ultrasonics

-  Used to Screen in-service pipes and pipeline over long distances -  Inspect pipes with limited access from a single position -  Pinpoint locations requiring further inspection -  Can provide significant reduction in operating costs -  Also known as LRUT, or long range ultrasonic testing

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes, and Training •  Conclusion

Industries •  Refineries •  Power Generation Plants •  Pipes and Piping in gas transportation stations •  Onshore pipelines •  Offshore risers and other piping systems •  DOT

Applications Corrosion detection / in-service pipes and pipelines

•  Inspection of above ground conventional and coated pipe •  Detection of corrosion at supports and pipe racks •  Inspection of through-wall pipe

Applications

•  Detection of corrosion under insulation (CUI) •  Inspection of buried pipes •  Inspection of vertical pipes •  Road Crossings

Corrosion detection / in-service pipes and pipelines

Applications •  Inspecting with guided waves avoids unnecessary excavation,

coating removal, or scaffolding if no flaw is detected. •  But it’s a screening tool:

- Areas of concerns need to be addressed with other NDT techniques. -Conventional Ultrasonics or Phased Array can be used to confirm the pipe condition.

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes, and Training •  Data Analysis •  Conclusion

Guided Waves compared to Conventional Ultrasonics

Inspection with Conventional Ultrasonics -  Localized inspection -  Underneath or in the vicinity of the sensor location -  Must remove all coverings, condition pipe for UT inspection -  Point measurement or mapping system

Inspection with Guided Waves (Long-Range Ultrasonic Testing)

-  Screens the entire pipe wall -  Long inspection range (182 meters/600 feet) -  From a single inspection position -  On each side of the probe collar

•  The system propagates low frequency waves:15 kHz to 85 kHz.

•  Guided Waves in use from around 1920s, in NDT heavily since around 1990s

•  The UltraWave system utilizes Piezoelectric sensors (probes).

•  Torsional waves are pulsed all around the pipe circumference (axisymmetric/no time delay) from each side of the probe collar.

•  Inspection distance can reach up to 91 meters (300 feet) from each side of the collar for a total of 182 meters (600 feet).

•  The inspection length varies, depending on

the pipe condition, coating and configuration

Basics of Guided Waves

Basics of Guided Waves LRUT does not provide an accurate measurement of wall-thickness variation but detects a general change in the total pipe cross sectional area (CSC).

• Equally sensitive to OD and ID corrosion. • Can estimate the circumferential extend (using focusing tools). • Other NDT methods are needed to validate indications.

5% CSC (Total area)

Distributed differently

Advantages of using Guided Waves •  High productivity inspection with long-range coverage and rapid

screening.

•  100% screening coverage of pipe wall, 360 degrees around the pipe circumference.

•  Ability to scan pipes with limited access such as coated, insulated,

buried, road-crossing, and through-wall pipes.

•  Cost reduction for excavation, scaffolding, and insulation removal.

•  Cost effective solution for pipe integrity management programs.

•  In-service inspection (no production shutdown).

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes and Training •  Conclusion

UltraWave LRT The system features the UltraWave LRT instrument, which is secured in a backpack, a rugged touch-screen laptop with software, flexible inspection collars, and all the necessary tools to perform an inspection.

Inspection Collar •  Probes assembled on

predefined bands for each pipe diameter (Standard kit 2 – 24 in. OD).

•  Bladder inflated to ensure good contact for the inspection.

•  No couplant is required.

•  Low profile design •  Fast and easy setup on the pipe •  Inspections with limited access •  Good contact (stability) between the

probe and the material during acquisition

•  Light and compact transport

Acquisition Unit and Laptop •  Battery operated,16-channel,

with broadband frequency range: 15 to 85 kHz.

•  Total inspection length: 182 meters (600 feet) in optimal conditions (91m/300 feet bidirectionally).

•  Getac V200 rugged, industrial touch-screen laptop computer with sunlight-readable display.

UW Software

•  Setup Wizard. •  Color mapping. •  Focusing modes. •  Easy reporting.

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes, and Training •  Data Analysis •  Conclusion

Inspection Sequence 1)  Pipe sketch 2)  Collar installation 3)  Axisymmetric scan 4)  A-scan analysis / features localisation 5)  Active focusing if necessary 6)  Synthetic focusing (can be done

during post-processing) 7)  Defect confirmation (UT or phased

array) 8)  Second acquisition, if necessary 9)  Final analysis and reporting

Pipe Sketch •  A drawing with notes on the pipe configuration is

mandatory for further analysis. •  Key features and there locations are identified with as

much or as little information is known.

Collar Installation •  Surface conditioning •  Pipe thickness measurement •  Band positioning •  Bladder inflation •  Wiring and coupling validation

Defining the Setup •  A user-friendly, step-by-step wizard is available in the

software to build the setup •  Information about the line dimension, location, thickness,

material, and coating are entered before acquisition

Axisymmetric Scan •  Guided waves are pulsed all around the pipe with no time delay •  Multiple frequencies are acquired simultaneously •  Analysis is performed on the most sensitive frequency •  A-scan is selected with the horizontal red cursor

Axisymmetric Scan •  F-Scan color map is a view of all frequencies acquired over the pipe

length •  Guided wave is a frequency-dependent detection method •  With the F-scan view, selecting the optimum frequency for further

analysis is fast & intuitive.This unique feature offers a global image of the inspected zone

•  Scan time varies, 1-3 minutes typical

Data acquired from 15 to 85 kHz with steps of 1 kHz

Dead Zone Defects

Flange Weld Weld

Preliminary A-Scan Analysis •  Known feature identification (weld, flange, visible indications). •  Distance amplitude correction (DAC) curve positioning. •  Pipe schematic updated with pre-selected symbols.

Active Focusing •  Energy focused at a determined distance and frequency. •  Induced time delay at 8 different positions around pipe. •  Polar plot that estimates the defect circumferential position and extent. •  Wave form representing the signal of each octant at it’s position on pipe. •  Provide improved penetration power, SNR, and inspection confidence for

advanced applications. •  Reduced defect false-alarm rates.

Synthetic Focusing •  C-scan view of unrolled pipe (channels vs. distance at 1 frequency). •  Generated considering the phase velocity of the received modes (from flexural). •  Provides the axial position and circumferential extent of all defects. •  Post-processing tool. •  Displays the entire inspected zone.

Defect Confirmation •  Inspect the zone of concern with complementary NDT

techniques.

Detection with Guided Waves

•  On above ground conventional pipe, with general good condition, Guided Wave have proven detection of defect size that corresponds to 3% of cross section area change (CSC).

•  This value will vary for advanced applications such as buried, coated, and heavily corroded pipes.

Detection with Guided Waves Results on 8in diameter pipe, schedule 40. The indication corresponds to 2.8% of the cross section area.

Detection with Guided Waves Results on 8in diameter pipe, schedule 40. The indication corresponds to 2.8% of the cross section area.

Detection with Guided Waves The defect shows in quadrant number 3 and is confirmed by active focusing:

Axisymmetric F-Scan view

Pipe  Support  with  corrosion  

Pipe  Support  with  corrosion   Corrosion  

Weld   Weld  Weld  

Dead  Zone  

Pipe  Support  with  corrosion  between  the  weld  and  

the  support  

Inspection of a pipe with multiple indications Supports appears at the lower frequencies while some corrosion also shown at the higher frequencies

A-Scan Analysis 23 kHz The green signal in the A-scan is the reverse overlay (from the other side of the probe collar). This software tool helps validating if the indication is a reverberation or not. Different wave mode content (flexural/torsional) help distinguish type of indication.

Reporting •  Annotations lists, with corresponding screen shots, are

automatically compiled in the report. •  Laptop integrated camera allows for quick picture

importation.

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes, and Training •  Conclusion

Codes and Standards

Guided Wave is covered by •  ASTM : E2775 - Standard Practice for Guided Wave Testing of Above

Ground Steel Pipework Using Piezoélectric Effect Transduction (2011) •  ASME : Article 18 – Guided Wave Testing Method for Basic Piping : not

released yet (in progress)

•  ISO / TC 44 & International Institute of Welding : Long Range Inspection of Above Ground Pipelines and Plant Piping Using Guided Wave Testing with Axial Propagation : not released yet (in progress)

•  JIS/NDIS 2427 : General rules for how to study flaw detection of a pipe by pulse echo method using guided wave

•  BS 9690 and 9690-2: Non-destructive testing. Guided wave testing. General guidance and principles/Non-destructive testing. Guided wave testing. Basic requirements for guided wave testing of pipes, pipelines and structural tubulars

Training and Certification

Guided Wave is covered by

•  BS/EN 473 : General principles for qualification and certification of Guided Wave Testing personnel

•  BS/EN 14748 : Non-destructive testing. Methodology for qualification of non-destructive tests

•  CSWIP ES NDT 12 04 /DOCUMENT No. CSWIP-ISO-NDT-11/93-R-

•  PCN GW GEN/Appendix A/General and Specific Requirements for Qualification and PCN Certification of Guided Wave Testing Personnel

•  SNT-TC-1A (ANSI/ASNT CP-105-2011)

Training •  Olympus offers training,

remote and on site technical support, as well as consultancy.

•  Need of customer is assessed for best training path and training plan is implimented –  Guided Wave Experience

(instrument training only) –  No Guided wave

Experience (theory and instrument training)

Agenda

•  Applications and Industries •  Basics of Guided Waves •  System Overview •  Inspection Sequence •  Standards, Codes, and Training •  Conclusion

Performing Guided Wave Inspection with UltraWave LRT

•  Long-range screening for pipe integrity assessment. •  Buried, coated, Supported and insulated pipe inspection

capability. •  Saves time and money pinpointing critical areas without

scaffolding, insulation removal etc.

Visit our website: www.olympus-ims.com