Radiographic Testing (RT)
Radiographic Testing (RT) Or Industrial Radiography Is A Non-Destructive Testing (NDT) Method Of Inspecting Materials For Hidden Flaws By Using The Ability Of Short Wavelength Electromagnetic Radiation (High-Energy Photons) To Penetrate Various Materials. X-Ray Machine Or Radioactive Isotope (Ir-192, Co-60 Or Cs-137) Can Be Used As A Source Of Photons. Radiation Emerging From The Opposite Side Of The Material Expose The Films In Various Intensity Due To The Internal Structure Of The Material. Exposed Films Are Later Developed To Study The Soundness & Integrity Of The Material.
X-Ray Pipeline Crawler
X-Ray Or Gamma Ray Crawler Is An Instrument Used To Check The Quality Of Welds In Long Distance Pipelines. It Is Used Mainly For The Inspection Of Welded Joint In Pipes Of Internal Diameter Range Of 6” To 48”. The Systems Are Battery Operated And Uses An Electronic Locating Device Or A Small Gamma Source For Location And Positioning Purposes, Giving An Accuracy Of Movement Of 5 Mm, Ideal For Positioning The X-Ray Tube Or Gamma Source To Inspect A Welded Joint. The Sensor Controller, Either Electronic Or Gamma (Cs 137), Stops The Crawler At A Defined Position.
Ultrasonic Testing (UT)
Ultrasonic Testing Is A Non-Destructive Testing Method, Which Utilizes High Frequency Sound Waves To Perform Volumetric Examinations Of Materials. Ultrasonic Testing Is Most Commonly Used To Detect Sub-Surface Flaws But, In Some Instances, It Can Also Be Used To Detect Surface Flaws As Well. Ultrasonic Testing Works By Introducing Sounds Waves Into The Material Under Test, These Waves Then Propagate Through The Material. Any Discontinuity In The Wave Path Will Cause Part Of The Sound Wave To Be Reflected Back, Which Is Then Detected And Displayed On The Ultrasonic Inspection Equipment.
Ultrasonic Testing Can Be Used In Inspection Of Weldments, Lamination Checks Of Material, Thickness Gauging And Corrosion Mapping Of In-Service Equipments.
Magnetic Particle Testing (Fluorescent & Visible)
Magnetic Particle Inspection Method Is Used To Detect Surface Breaking Flaws (And In Some Cases Near Sub-Surface Flaws) In Ferromagnetic Materials. The Object Under Test Is Magnetized And An Ink Or Powder Containing Ferromagnetic Particles Is Applied To The Test Area. If There Is Discontinuity In The Object, Then Flux Leakage Occurs And Collection Of Iron Particles At The Flaw Location. This Allows The Identification Of Flaws In The Test Objects.
Liquid Penetrant Testing (Fluorescent & Visible)
Liquid Penetrant Testing Is Used To Detect Surface Breaking Flaws, Which Is Not Restricted To Just Ferromagnetic Materials But All Non-Porous Materials. The Method Is Based On A Liquid Penetrant Being Applied To The Test Area By Using The Capillary Effect To Draw The Liquid In Any Surface Breaking Flaws.
Once Excess Penetrant Has Been Removed From The Test Piece A Coat Of Developer Is Applied Causing The Penetrant In Any Surface Breaking Flaws To ‘Bleed’ Out To The Surface Allowing For The Flaw To Be Easily Identified.
Visual Testing
Visual Testing Is Probably The Most Important Of All Non-Destructive Tests. It Can Often Provide Valuable Information To The Well Trained Eye. Visual Features May Be Related To Workmanship, Structural Serviceability, And Material Deterioration And It Is Particularly Important That The Engineer Is Able To Differentiate Between The Various Signs Of Distress Which May Be Encountered. These Include For Instance, Cracks, Pop-Outs, Spalling, Disintegration, Colour Change, Weathering, Staining, Surface Blemishes And Lack Of Uniformity. Extensive Information Can Be Gathered From Visual Inspection To Give A Preliminary Indication Of The Condition Of The Structure And Allow Formulation Of A Subsequent Testing Programme.
Magnetic Particle Testing (Fluorescent & Visible)
Hardness Is The Measure Of How Resistant Solid Matter Is To Various Kinds Of Permanent Shape Change When A Force Is Applied. Strong Intermolecular Bonds Generally Characterize Macroscopic Hardness, But The Behavior Of Solid Materials Under Force Is Complex; Therefore, There Are Different Measurements Of Hardness: Indentation Hardness And Rebound Hardness. Hardness Is Dependent On Ductility, Elastic Stiffness, Plasticity, Strain, Strength, Toughness, Viscoelasticity, And Viscosity.
Vacuum Box Testing
Vacuum Box Testing Is A Non-Destructive Examination Used When Trying To Locate Weld Seam Leaks. A Vacuum Box And A Compressor Create A High- Or Low-Pressure Vacuum While A Detergent Solution Is Applied To The Test Area. The Detergent Bubbles, Make Leaks Visible Within The Created Pressure Envelope. Applications Includes Lap Welds, Butt Welds And Shell To Annular Welds, Piping Systems And Pressure Vessels, Tank Bottoms, ERW Seamed Pipe In Pipelines, Etc.
Advantages: Provides An Immediate Indication Of The Location Of Any Leaks Present & Can Detect Small Leaks Within A Given Area.
>Ferrite Box Testing
Ferrite Testing Is Used To Determine The Ferrite Content As Ferrite Number (FN) As Well As % Ferrite For Welding, Piping, Austenitic And Duplex Stainless Steel. Ferrite Content Analysis Is A Non-Destructive Testing Method Which Provides Critical Data For Austenitic Stainless Steel And Duplex Materials. The Ferrite Percentage Or Number Allows A Technical Assessment Of Material Corrosion Susceptibility, Mechanical Properties, Service Suitability, And Service Reliability.
In Order To Perform The Test Properly, A Minimum Material Thickness And A Minimum Specimen Size Are Required. Test Results Are Interpreted In Accordance With Current Specifications And/Or Customer Requirements. Reports Issued Are Accompanied By Drawings To Identify Locations Tested When Necessary. Advantages Of FT Are Rapid, Accurate Analysis And Microprocessor Based Digital Technology.
Advantages:
Provides an immediate indication visual of the location of any leaks present & can detect small leaks within a given area.