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NON-DESTRUCTIVE EXAMINATION OF PUMPS

PRESENTED BY

JOSEPH HEALEY, P.ENG, CFEI

ACUREN GROUP INC.

WWW.ACUREN.COM

NDE Overview

• Non-Destructive Examination or Evaluation (NDE)

• Also referred to as Non-Destructive Testing (NDT)

– The act of evaluating a material or component with out – The act of evaluating a material or component with out

degrading the integrity or serviceability of the material or

component.

Purpose for Application of NDE on Pumps

• To verify integrity and specifications of new pumps

and systems.

• To evaluate in-service condition.

• To monitor in-service degradation.• To monitor in-service degradation.

• To prevent failure and loss.

Typical Pump Issues Evaluated by NDE

• Corrosion, Erosion, and Cavitation material loss.

• Cracking.

• Thermal degradation.

• Vibration wear and fatigue.• Vibration wear and fatigue.

• Coating deterioration.

• Connected piping systems

Cavitation Erosion

Traditional Challenges for NDE on Pumps

• Access

• Complex Geometries

• Coatings

• Difficult Materials• Difficult Materials

Approach to NDE of Pumps

• Evaluate as a system

– Pumps can often cause failure elsewhere in a system

• Identify governing codes, standards, and practices

• Gather operational history and Failure history of • Gather operational history and Failure history of

similar systems

• Have drawings and material lists available

Typical NDE Technologies and Techniques used on Pumps

• Classic/Code Techniques

– Visual examination

– Ultrasonic (UT)

– Radiography (RT)

• Advanced/Supplemental

Techniques

– Eddy Current Testing (ET)

– Acoustic Emission (AE)

– Magnetic Particle

Inspection (MT/MPI)

– Liquid Penetrant (PT/LPI)

– Vibration Analysis

– Strain gauging

– Thermography

– In-situ Metallography

– Hardness testing

– PMI

Applicable Codes and Standards

• API 610 / ISO 13709

– Centrifugal Pumps

• API 674

– Positive Displacement

• ASME Boiler and Pressure

Vessel Code

– Section V – Non-destructive

Examination

– Section VIII - Rules for – Positive Displacement

Pumps - Reciprocating

• API 681

– Liquid Ring Vacuum Pumps

and Compressors

• API 685

– Sealless Centrifugal Pumps

– Section VIII - Rules for

Construction of Pressure

Vessels

• ASME B31.1, B31.3

• CSA Z662, CSA B51

API 610 Inspection Standards

Standards and Codes Development Cycle

Industry NDT

Components in Service

Industry NDT

Failure Analysis

Failures

Detected

Causes

Addressed

Visual Examination

• Abbreviation VT – Visual testing.

• The backbone and oldest non-destructive method.

• Relies on human visual acuity and interpretation.

• Can be aided by microscopes, boroscopes, video • Can be aided by microscopes, boroscopes, video

crawlers.

• Often easily documented with high quality

photography.

• Initial inspection method before all other methods.

• Can examine fit of components such as seals.

Visual Examination Limitations

• Restricted access.

• Internal flaws.

• Interpretation and experience.

• Critical defect size often not visible to the naked • Critical defect size often not visible to the naked

• Defects are often in the wrong profile to be visually

detected.

Ultrasonic Testing (UT)

IP: INITIAL PULSE

DE: DEFECT ECHO

BWE: BACK WALL ECHO

DEFECT

TRANSDUCER

TEST PIECE

Ultrasonic Testing (UT)

• Utilizes the emission and detection of high

frequency, low amplitude, mechanical stress waves

through a material.

• Equipment primarily consists of piezoelectric • Equipment primarily consists of piezoelectric

transducer crystals and an oscilloscope.

• Detects discontinuities in materials based upon

interpretation of reflected wave characteristics

UT Techniques

• Pulse Echo 0° or Straight Beam

• Shearwave

• Phased Array (PA)

• Time-of-Flight-Defraction (TOFD)• Time-of-Flight-Defraction (TOFD)

UT Limations

• Geometric Traps.

• Material quality.

• Casting grain size.

• Material acoustic transmission properties.• Material acoustic transmission properties.

• Surface condition.

Radiography (RT)

• Utilizes radiation to image surface and internal

features of a material or component.

• Relies upon a radiation source, either tube

generated or radioactive isotope, and a radiation generated or radioactive isotope, and a radiation

sensitive media or film.

• Typical in-situ field radiography is performed with

gamma radiation from Cobalt 60 or Iridium 192

isotope sources.

Common RT Techniques

• Film radiography

• Digital radiography

• Computed Radiography

RT Application

Radiography Safety

• Appropriate access, space, and time (shooting

window).

• Highly regulated and monitored activity.

• Exposure levels are generally lower than other • Exposure levels are generally lower than other

occupations.

• Respect for barriers is critical.

Radiography Limitations

• Material type and thickness.

• Material geometry.

• Source intensity and film quality and speed.

• Safe access. • Safe access.

• Plane of discontinuity relative to plane of film and

source.

• Relies upon the visual interpretation of the captured

image.

Magnetic Particle Inspection (MPI/MT)

• Surface defect evaluation

technique.

• Relies upon the visual

interpretation of patterns of interpretation of patterns of

magnetic particles applied

to the surface and

influenced by a directional

magnetic field induced in

the material.

Common Types of MPI/MT

• Wet Colour Contrast – commonly referred to as

black and white.

• Dry particle – common for weld root and elevated

temperature inspection.temperature inspection.

• Wet Fluorescence – highest degree of detection.

MPI/MT Limitations

• Material must be ferro-magnetic.

• Material surface must be satisfactorily clean.

• Limit of detection is often dependant on surface

polish condition. polish condition.

• Can be affected by residual magnetization and EMF

fields.

Stress corrosion cracking found on pipe

Liquid Penetrant Inspection (LPI/PT)

• Surface defect evaluation technique.

• Relies upon the visual interpretation of patterns of

die penetrants applied to the surface and

developed. developed.

• Can be colour contrast or florescent.

LPI/PT Requirements and Limitations

• Material surface must normally be non-absorbant .

• Material surface must be satisfactorily clean.

• Limit of detection is often dependant on surface

polish condition. polish condition.

• Can be affected by surface features and

contaminants in surface breaking discontinuities.

LPI on Progressive Cavity Pump Rotor

Eddy Current Testing (ET)

• Uses measurement of variation in induced eddy

current field flow to detect discontinuities in non-

magnetic metallic materials.

• Relies upon the visual interpretation of the field • Relies upon the visual interpretation of the field

return patterns.

Thermography

• Visual imaging of infrared

radiation.

• Can be used to analyze

heat loss and heat flaring. 200

heat loss and heat flaring.

• Excess heat is often

associated with excessive

wear, bearing and

lubrication issues.

• Excellent tool for predictive

maintenance.

Thermography

Acoustic Emission (AE)

• Acoustic Emission is essentially ultrasonics without

remote wave generation.

• Ultrasonic transducers are used to measure and

monitor sonic waves generated in material by a monitor sonic waves generated in material by a

change in stress.

• Generally used for longer term or near failure

monitoring

Vibration Analysis

• The measurement of induced or resonant vibration

using accelerometers.

• Useful as a monitoring and preventative

maintenance system.maintenance system.

• Can help prevent or indentify causes of fatigue and

bearing failures

Hardness Testing

In-situ Hardness Testing

• Used to measure the

surface hardness of a

metal component.

• Hardness can be related to • Hardness can be related to

strength.

• Required for sour service

• Can be used to monitor in

service hardening or

softening due to wear or

thermal issues.

In-situ Replication

• Non-destructive method of

evaluating microstructure

of metal components.

• Evaluates surface layer • Evaluates surface layer

with minor surface

prepartation.

Positive Material Identification

• Provides the ability to identify or verify the material

of a component.

• Two primary in-situ non-destructive methods are x-

ray fluorescences (XRF) and spark spectroscopy.ray fluorescences (XRF) and spark spectroscopy.

• Some light element and accuracy limitations.

Nondestructive Testing & Quality

• NDE methods exhibit limitations– Probability of detection (POD)

– Reflectivity, absorption, attenuation

– Accuracy of sizing in three dimensions

– Access, environment, service

• Operator dependence

• Many tradeoffs exist• Many tradeoffs exist– Sensitivity vs. penetration

– Speed of inspection (screening) vs. accuracy (quantitative measurement)

Ways to Improve NDT Reliability

• Use multiple methods

– confirm indication

– separate detection and sizing

• Employ advanced technologies

• Process sign off (PSO)• Process sign off (PSO)

• Performance demonstration

• Training (beyond ASTN & CGSB)

• Test procedures & techniques

• Report review and auditing

• Automation

• Clarity around limitations

Advanced Test Methods

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