Welding Inspection Cswip

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Welding Inspection Cswip

  1. 1. Welding Inspector Duties and Responsibilities Section 1 4/23/2007 1 of 691
  2. 2. Main Responsibilities 1.1 • Code compliance • Workmanship control • Documentation control 4/23/2007 2 of 691
  3. 3. Personal Attributes 1.1 Important qualities that good Inspectors are expected to have are: • Honesty Integrity • •Knowledge •Good communicator Physical fitness • • Good eyesight 4/23/2007 3 of 691
  4. 4. Standard for Visual Inspection 1.1 Basic Requirements BS EN 970 - Non-destructive examination of fusion welds - Visual examination Welding Inspection Personnel should: • be familiar with relevant standards, rules and specifications applicable to the fabrication work to be undertaken • be informed about the welding procedures to be used • have good vision (which should be checked every 12 months) 4/23/2007 4 of 691
  5. 5. Welding Inspection 1.2 Conditions for Visual Inspection (to BS EN 970) Illumination: • 350 lux minimum required • (recommends 500 lux - normal shop or office lighting) Vision Access: • eye should be within 600mm of the surface • viewing angle (line from eye to surface) to be not less than 30° 600mm 30° 4/23/2007 5 of 691
  6. 6. Welding Inspection 1.3 Aids to Visual Inspection (to BS EN 970) When access is restricted may use: • a mirrored boroscope • a fibre optic viewing system } usually by agreement Other aids: • welding gauges (for checking bevel angles, weld profile, fillet sizing, undercut depth) • dedicated weld-gap gauges and linear misalignment (high-low) gauges • straight edges and measuring tapes • magnifying lens (if magnification lens used it should have magnification between X2 to X5) 4/23/2007 6 of 691
  7. 7. Welding Inspectors Equipment 1.3 Measuring devices: • flexible tape, steel rule • Temperature indicating crayons • Welding gauges • Voltmeter • Ammeter • Magnifying glass • Torch / flash light • Gas flow-meter 4/23/2007 7 of 691
  8. 8. Welding Inspectors Gauges 1.3 10mm 10mm 1 2 G.A.L. G.A.L. 3 4 S.T.D. L S.T.D. 16mm 5 16mm 6 Fillet Weld Gauges HI-LO Single Purpose Welding Gauge IN 0 1/4 1/2 3/4 TWI Multi-purpose Welding Gauge Misalignment Gauges Hi-Lo Gauge 4/23/2007 8 of 691
  9. 9. Welding Inspectors Equipment 1.3 Voltmeter Ammeter Tong Tester 4/23/2007 9 of 691
  10. 10. Welding Inspection 1.3 Stages of Visual Inspection (to BS EN 970) Extent of examination and when required should be defined in the application standard or by agreement between the contracting parties For high integrity fabrications inspection required throughout the fabrication process: Before welding (Before assemble & After assembly) During welding After welding 4/23/2007 10 of 691
  11. 11. Typical Duties of a Welding Inspector 1.5 Before Welding Preparation: Familiarisation with relevant „documents‟… • Application Standard/Code - for visual acceptance requirements • Drawings - item details and positions/tolerances etc • Quality Control Procedures - for activities such as material handling, documentation control, storage & issue of welding consumables • Quality Plan/Inspection & Test Plan/Inspection Checklist - details of inspection requirements, inspection procedures & records required 4/23/2007 11 of 691
  12. 12. Typical Duties of a Welding Inspector 1.5 Before Welding Welding Procedures: • are applicable to joints to be welded & approved • are available to welders & inspectors Welder Qualifications: • list of available qualified welders related to WPS‟s • certificates are valid and ‘in-date’ 4/23/2007 12 of 691
  13. 13. Typical Duties of a Welding Inspector 1.5 Before Welding Equipment: • all inspection equipment is in good condition & calibrated as necessary • all safety requirements are understood & necessary equipment available Materials: • can be identified & related to test certificates, traceability ! • are of correct dimensions • are in suitable condition (no damage/contamination) 4/23/2007 13 of 691
  14. 14. Typical Duties of a Welding Inspector 1.5 Before Welding Consumables: • in accordance with WPS’s • are being controlled in accordance with Procedure Weld Preparations: • comply with WPS/drawing • free from defects & contamination Welding Equipment: • in good order & calibrated as required by Procedure 4/23/2007 14 of 691
  15. 15. Typical Duties of a Welding Inspector 1.5 Before Welding Fit-up • complies with WPS • Number / size of tack welds to Code / good workmanship Pre-heat • if specified • minimum temperature complies with WPS 4/23/2007 15 of 691
  16. 16. Typical Duties of a Welding Inspector 1.5 During Welding Weather conditions • suitable if site / field welding Welding Process(es) • in accordance with WPS Welder • is approved to weld the joint Pre-heat (if required) • minimum temperature as specified by WPS • maximum interpass temperature as WPS 4/23/2007 16 of 691
  17. 17. Typical Duties of a Welding Inspector 1.6 During Welding Welding consumables • in accordance with WPS • in suitable condition • controlled issue and handling Welding Parameters • current, voltage & travel speed – as WPS Root runs • if possible, visually inspect root before single-sided welds are filled up 4/23/2007 17 of 691
  18. 18. Typical Duties of a Welding Inspector 1.6 During Welding Inter-run cleaning in accordance with an approved method (& back gouging) to good workmanship standard Distortion control • welding is balanced & over-welding is avoided 4/23/2007 18 of 691
  19. 19. Typical Duties of a Welding Inspector 1.6 After Welding Weld Identification • identified/numbered as required • is marked with welder‟s identity Visual Inspection • ensure weld is suitable for all NDT • visually inspect & „sentence‟ to Code requirements Dimensional Survey • ensure dimensions comply with Code/drawing Other NDT • ensure all NDT is completed & reports available 4/23/2007 19 of 691
  20. 20. Typical Duties of a Welding Inspector 1.6 After Welding Repairs • monitor repairs to ensure compliance with Procedure, ensure NDT after repairs is completed • PWHT • monitor for compliance with Procedure • check chart records confirm Procedure compliance Pressure / Load Test • ensure test equipment is suitably calibrated • monitor to ensure compliance with Procedure • ensure all records are available 4/23/2007 20 of 691
  21. 21. Typical Duties of a Welding Inspector 1.6 After Welding Documentation • ensure any modifications are on ‘as-built’ drawings • ensure all required documents are available • Collate / file documents for manufacturing records • Sign all documentation and forward it to QC department. 4/23/2007 21 of 691
  22. 22. Summary of Duties It is the duty of a Welding Inspector to ensure all the welding and associated actions are carried out in accordance with the specification and any applicable procedures. A Welding Inspector must: • Observe To observe all relevant actions related to weld quality throughout production. • Record To record, or log all production inspection points relevant to quality, including a final report showing all identified imperfections • Compare To compare all recorded information with the acceptance criteria and any other relevant clauses in the applied application standard 4/23/2007 22 of 691
  23. 23. Welding Inspector Terms & Definitions Section 2 4/23/2007 23 of 691
  24. 24. Welding Terminology & Definitions 2.1 What is a Weld? • A localised coalescence of metals or non-metals produced either by heating the materials to the welding temperature, with or without the application of pressure, or by the application of pressure alone (AWS) • A permanent union between materials caused by heat, and or pressure (BS499) • An Autogenous weld: A weld made with out the use of a filler material and can only be made by TIG or Oxy-Gas Welding 4/23/2007 24 of 691
  25. 25. Welding Terminology & Definitions 2.1 What is a Joint? • The junction of members or the edges of members that are to be joined or have been joined (AWS) • A configuration of members (BS499) 4/23/2007 25 of 691
  26. 26. Joint Terminology 2.2 Edge Open & Closed Corner Lap Tee Butt Cruciform 4/23/2007 26 of 691
  27. 27. Welded Butt Joints 2.2 Butt A_________Welded butt joint Fillet A_________Welded butt joint Compound A____________Welded butt joint 4/23/2007 27 of 691
  28. 28. Welded Tee Joints 2.2 Fillet A_________Welded T joint Butt A_________Welded T joint Compound A____________Welded T joint 4/23/2007 28 of 691
  29. 29. Weld Terminology 2.3 Butt weld Spot weld Fillet weld Edge weld Plug weld Compound weld 4/23/2007 29 of 691
  30. 30. Butt Preparations – Sizes 2.4 Partial Penetration Butt Weld Actual Throat Design Throat Thickness Thickness Full Penetration Butt Weld Design Throat Actual Throat Thickness Thickness 4/23/2007 30 of 691
  31. 31. Weld Zone Terminology 2.5 Face A B Weld metal Heat Weld Affected Boundary Zone C D Root A, B, C & D = Weld Toes 4/23/2007 31 of 691
  32. 32. Weld Zone Terminology 2.5 Weld cap width Excess Cap height Actual Throat Design or Weld Thickness Throat Reinforcement Thickness Excess Root Penetration 4/23/2007 32 of 691
  33. 33. Heat Affected Zone (HAZ) 2.5 Maximum solid solid-liquid Boundary Temperature weld grain growth zone metal recrystallised zone partially transformed zone tempered zone unaffected base material 4/23/2007 33 of 691
  34. 34. Joint Preparation Terminology 2.7 Included angle Included angle Angle of bevel Root Radius Root Face Root Face Root Gap Root Gap Single-V Butt Single-U Butt 4/23/2007 34 of 691
  35. 35. Joint Preparation Terminology 2.8 & 2.9 Angle of bevel Angle of bevel Root Radius Root Face Root Gap Root Face Root Gap Land Single Bevel Butt Single-J Butt 4/23/2007 35 of 691
  36. 36. Single Sided Butt Preparations 2.10 Single sided preparations are normally made on thinner materials, or when access form both sides is restricted Single Bevel Single Vee Single-J Single-U 4/23/2007 36 of 691
  37. 37. Double Sided Butt Preparations 2.11 Double sided preparations are normally made on thicker materials, or when access form both sides is unrestricted Double -Bevel Double -Vee Double - J Double - U 4/23/2007 37 of 691
  38. 38. Weld Preparation Terminology & Typical Dimensions: V-Joints bevel angle included angle root face root gap Typical Dimensions bevel angle 30 to 35° root face ~1.5 to ~2.5mm root gap ~2 to ~4mm 4/23/2007 38 of 691
  39. 39. Butt Weld - Toe Blend 6 mm •Most codes quote the weld toes shall blend smoothly 80 •This statement is not quantitative and therefore open to individual Poor Weld Toe Blend Angle interpretation 3 mm •The higher the toe blend angle the greater the 20 amount of stress concentration •The toe blend angle ideally Improved Weld Toe Blend Angle should be between 20o-30o 4/23/2007 39 of 691
  40. 40. Fillet Weld Features 2.13 Excess Weld Metal Vertical Leg Length Design Throat Horizontal leg Length 4/23/2007 40 of 691
  41. 41. Fillet Weld Throat Thickness 2.13 a b a = Design Throat Thickness b = Actual Throat Thickness 4/23/2007 41 of 691
  42. 42. Deep Penetration Fillet Weld Features 2.13 a a = Design Throat Thickness b b = Actual Throat Thickness 4/23/2007 42 of 691
  43. 43. Fillet Weld Sizes 2.14 Calculating Throat Thickness from a known Leg Length: Design Throat Thickness = Leg Length x 0.7 Question: The Leg length is 14mm. What is the Design Throat? Answer: 14mm x 0.7 = 10mm Throat Thickness 4/23/2007 43 of 691
  44. 44. Fillet Weld Sizes 2.14 Calculating Leg Length from a known Design Throat Thickness: Leg Length = Design Throat Thickness x 1.4 Question: The Design Throat is 10mm. What is the Leg length? Answer: 10mm x 1.4 = 14mm Leg Length 4/23/2007 44 of 691
  45. 45. Features to Consider 2 2.14 Importance of Fillet Weld Leg Length Size (a) (b) 8mm 4mm 4mm 2mm Approximately the same weld volume in both Fillet Welds, but the effective throat thickness has been altered, reducing considerably the strength of weld B 4/23/2007 45 of 691
  46. 46. Fillet Weld Sizes 2.14 Importance of Fillet weld leg length Size (a) (b) Excess Excess 4mm 6mm (a) (b) 4mm 6mm Area = 4 x 4 = Area = 6 x 6 = 8mm2 18mm2 2 2 The c.s.a. of (b) is over double the area of (a) without the extra excess weld metal being added 4/23/2007 46 of 691
  47. 47. Fillet Weld Profiles 2.15 Fillet welds - Shape Mitre Fillet Convex Fillet A concave profile is preferred for joints subjected to Concave Fillet fatigue loading 4/23/2007 47 of 691
  48. 48. Fillet Features to Consider 2.15 EFFECTIVE THROAT THICKNESS “a” = Nominal throat thickness “s” = Effective throat thickness a s Deep penetration fillet welds from high heat input welding process MAG, FCAW & SAW etc 4/23/2007 48 of 691
  49. 49. Welding Positions 2.17 PA 1G / 1F Flat / Downhand PB 2F Horizontal-Vertical PC 2G Horizontal PD 4F Horizontal-Vertical (Overhead) PE 4G Overhead PF 3G / 5G Vertical-Up PG 3G / 5G Vertical-Down H-L045 6G Inclined Pipe (Upwards) J-L045 6G Inclined Pipe (Downwards) 4/23/2007 49 of 691
  50. 50. Welding Positions 2.17 ISO 4/23/2007 50 of 691
  51. 51. Welding position designation 2.17 Butt welds in plate (see ISO 6947) Flat - PA Overhead - PE Vertical up - PF Vertical Horizontal - PC down - PG 4/23/2007 51 of 691
  52. 52. Welding position designation 2.17 Butt welds in pipe (see ISO 6947) Vertical up - PF Vertical down - PG Flat - PA axis: horizontal axis: horizontal axis: horizontal pipe: fixed pipe: fixed pipe: rotated H-L045 J-L045 Horizontal - PC axis: inclined at 45° axis: inclined at 45° axis: vertical pipe: fixed pipe: fixed pipe: fixed 4/23/2007 52 of 691
  53. 53. Welding position designation 2.17 Fillet welds on plate (see ISO 6947) Flat - PA Horizontal - PB Overhead - PD Vertical up - PF Vertical down - PG 4/23/2007 53 of 691
  54. 54. Welding position designation 2.17 Fillet welds on pipe (see ISO 6947) Flat - PA Horizontal - PB Overhead - PD axis: inclined at 45° axis: vertical axis: vertical pipe: rotated pipe: fixed pipe: fixed Horizontal - PB Vertical up - PF Vertical down - PG axis: horizontal axis: horizontal axis: horizontal pipe: rotated pipe: fixed pipe: fixed 4/23/2007 54 of 691
  55. 55. Plate/Fillet Weld Positions 2.17 PA / 1G PA / 1F PF / 3G PB / 2F PC / 2G PE / 4G PG / 3G PD / 4F 4/23/2007 55 of 691
  56. 56. Pipe Welding Positions 2.17 PF / 5G PG / 5G PA / 1G Weld: Flat Weld: Vertical upwards Weld: Vertical Downwards Pipe: rotated Pipe: Fixed Pipe: Fixed Axis: Horizontal Axis: Horizontal Axis: Horizontal 45o 45o PC / 2G H-LO 45 / 6G J-LO 45 / 6G Weld: Horizontal Weld: Upwards Weld: Downwards Pipe: Fixed Pipe: Fixed Pipe: Fixed Axis: Vertical Axis: Inclined Axis: Inclined 4/23/2007 56 of 691
  57. 57. Travel Speed Measurement 2.18 Definition: the rate of weld progression measured in case of mechanised and automatic welding processes in case of MMA can be determined using ROL and arc time 4/23/2007 57 of 691
  58. 58. Welding Inspector Welding Imperfections Section 3 4/23/2007 58 of 691
  59. 59. Welding Imperfections 3.1 All welds have imperfections • Imperfections are classed as defects when they are of a type, or size, not allowed by the Acceptance Standard A defect is an unacceptable imperfection • A weld imperfection may be allowed by one Acceptance Standard but be classed as a defect by another Standard and require removal/rectification 4/23/2007 59 of 691
  60. 60. Welding Imperfections 3.1 Standards for Welding Imperfections BS EN ISO 6520-1(1998) Welding and allied processes – Classification of geometric imperfections in metallic materials - Part 1: Fusion welding Imperfections are classified into 6 groups, namely: 1 Cracks 2 Cavities 3 Solid inclusions 4 Lack of fusion and penetration 5 Imperfect shape and dimensions 6 Miscellaneous imperfections 4/23/2007 60 of 691
  61. 61. Welding Imperfections 3.1 Standards for Welding Imperfections EN ISO 5817 (2003) Welding - Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) - Quality levels for imperfections This main imperfections given in EN ISO 6520-1 are listed in EN ISO 5817 with acceptance criteria at 3 levels, namely Level B (highest) Level C (intermediate) Level D (general) This Standard is „directly applicable to visual testing of welds‟ ...(weld surfaces & macro examination) 4/23/2007 61 of 691
  62. 62. Welding imperfections 3.1 classification Cracks 4/23/2007 62 of 691
  63. 63. Cracks 3.1 Cracks that may occur in welded materials are caused generally by many factors and may be classified by shape and position. Classified by Shape Classified by Position •Longitudinal •HAZ •Transverse •Centerline •Chevron •Crater •Lamellar Tear •Fusion zone •Parent metal Note: Cracks are classed as Planar Defects. 4/23/2007 63 of 691
  64. 64. Cracks 3.1 Longitudinal parent metal Transverse weld metal Longitudinal weld metal Lamellar tearing 4/23/2007 64 of 691
  65. 65. Cracks 3.1 Transverse crack Longitudinal crack 4/23/2007 65 of 691
  66. 66. Cracks 3.2 Main Crack Types • Solidification Cracks • Hydrogen Induced Cracks • Lamellar Tearing • Reheat cracks 4/23/2007 66 of 691
  67. 67. Cracks 3.2 Solidification Cracking • Occurs during weld solidification process • Steels with high sulphur impurities content (low ductility at elevated temperature) • Requires high tensile stress • Occur longitudinally down centre of weld 4/23/2007 67 of 691
  68. 68. Cracks 3.3 Hydrogen Induced Cold Cracking • Requires susceptible hard grain structure, stress, low temperature and hydrogen • Hydrogen enters weld via welding arc mainly as result of contaminated electrode or preparation • Hydrogen diffuses out into parent metal on cooling • Cracking developing most likely in HAZ 4/23/2007 68 of 691
  69. 69. Lamellar Tearing 3.5 • Location: Parent metal • Steel Type: Any steel type possible • Susceptible Microstructure: Poor through thickness ductility • Lamellar tearing has a step like appearance due to the solid inclusions in the parent material (e.g. sulphides and silicates) linking up under the influence of welding stresses • Low ductile materials in the short transverse direction containing high levels of impurities are very susceptible to lamellar tearing • It forms when the welding stresses act in the short transverse direction of the material (through thickness direction) 4/23/2007 69 of 691
  70. 70. Gas Cavities 3.6 Gas pore Cluster porosity Causes: •Loss of gas shield •Damp electrodes •Contamination Blow hole •Arc length too large Herringbone porosity •Damaged electrode flux •Moisture on parent material •Welding current too low Gas pore <1.5mm Root piping Blow hole.>1.6mm 4/23/2007 70 of 691
  71. 71. Gas Cavities 3.7 Porosity Root piping 4/23/2007 71 of 691
  72. 72. Gas Cavities 3.8 Cluster porosity Herringbone porosity 4/23/2007 72 of 691
  73. 73. Crater Pipe 3.9 Weld crater Crater pipe 4/23/2007 73 of 691
  74. 74. Crater Pipe 3.9 Crater pipe is a shrinkage defect and not a gas defect, it has the appearance of a gas pore in the weld crater Crater cracks Causes: (Star cracks) • Too fast a cooling rate • Deoxidization reactions and liquid to solid Crater pipe volume change • Contamination 4/23/2007 74 of 691
  75. 75. Solid Inclusions 3.10 Slag inclusions are defined as a non-metallic inclusion caused by some welding process Causes: •Slag originates from welding flux Slag inclusions Lack of sidewall •MAG and TIG welding fusion with process produce silica associated slag inclusions •Slag is caused by inadequate cleaning •Other inclusions include Parallel slag lines Lack of interun tungsten and copper fusion + slag inclusions from the TIG and MAG welding process 4/23/2007 75 of 691
  76. 76. Solid Inclusions 3.11 Interpass slag inclusions Elongated slag lines 4/23/2007 76 of 691
  77. 77. Welding Imperfections 3.13 Typical Causes of Lack of Fusion: • welding current too low • bevel angle too steep • root face too large (single-sided weld) • root gap too small (single-sided weld) • incorrect electrode angle • linear misalignment • welding speed too high • welding process related – particularly dip-transfer GMAW • flooding the joint with too much weld metal (blocking Out) 4/23/2007 77 of 691
  78. 78. Lack of Fusion 3.13 Causes: •Poor welder skill • Incorrect electrode Incomplete filled groove + manipulation Lack of sidewall fusion • Arc blow • Incorrect welding 1 current/voltage 2 • Incorrect travel speed 1. Lack of sidewall fusion • Incorrect inter-run cleaning 2. Lack of inter-run fusion 4/23/2007 78 of 691
  79. 79. Lack of Fusion 3.13 Lack of sidewall fusion + incomplete filled groove 4/23/2007 79 of 691
  80. 80. Weld Root Imperfections 3.15 Lack of Root Fusion Lack of Root Penetration 4/23/2007 80 of 691
  81. 81. Cap Undercut 3.18 Intermittent Cap Undercut 4/23/2007 81 of 691
  82. 82. Undercut 3.18 Root undercut Cap undercut 4/23/2007 82 of 691
  83. 83. Surface and Profile 3.19 Incomplete filled groove Poor cap profile Poor cap profiles and excessive cap reinforcements may lead to stress concentration points at the weld toes and will also contribute to overall poor toe blend Excessive cap height 4/23/2007 83 of 691
  84. 84. Surface and Profile 3.19 Excess cap reinforcement Incomplete filled groove 4/23/2007 84 of 691
  85. 85. Weld Root Imperfections 3.20 Excessive root penetration 4/23/2007 85 of 691
  86. 86. Overlap 3.21 An imperfection at the toe or root of a weld caused by metal flowing on to the surface of the parent metal without fusing to it Causes: •Contamination •Slow travel speed •Incorrect welding technique •Current too low 4/23/2007 86 of 691
  87. 87. Overlap 3.21 Toe Overlap Toe Overlap 4/23/2007 87 of 691
  88. 88. Set-Up Irregularities 3.22 Linear misalignment is measured from the lowest plate to the highest point. Plate/pipe Linear Misalignment (Hi-Lo) Angular misalignment is measured in degrees Angular Misalignment 4/23/2007 88 of 691
  89. 89. Set-Up Irregularities 3.22 Linear Misalignment 4/23/2007 89 of 691
  90. 90. Set-Up Irregularities 3.22 Linear Misalignment 4/23/2007 90 of 691
  91. 91. Incomplete Groove 3.23 Lack of sidewall fusion + incomplete filled groove 4/23/2007 91 of 691
  92. 92. Weld Root Imperfections 3.24 A shallow groove, which may occur in the root of a butt weld Causes: • Excessive back purge pressure during TIG welding Excessive root bead grinding before the application of the second pass Concave Root welding current too high for 2nd pass overhead welding root gap too large - excessive „weaving‟ 4/23/2007 92 of 691
  93. 93. Weld Root Imperfections 3.24 Concave Root 4/23/2007 93 of 691
  94. 94. Weld Root Imperfections 3.24 Concave root Excess root penetration 4/23/2007 94 of 691
  95. 95. Weld Root Imperfections 3.25 A localized collapse of the weld pool due to excessive penetration resulting in a hole in the root run Causes: • High Amps/volts • Small Root face • Large Root Gap • Slow Travel Burn through Speed 4/23/2007 95 of 691
  96. 96. Weld Root Imperfections 3.25 Burn Through 4/23/2007 96 of 691
  97. 97. Oxidized Root (Root Coking) Causes: • Loss or insufficient back purging gas (TIG) • Most commonly occurs when welding stainless steels • Purging gases include argon, helium and occasionally nitrogen 4/23/2007 97 of 691
  98. 98. Miscellaneous Imperfections 3.26 Causes: • Accidental striking of the arc onto the parent material • Faulty electrode holder • Poor cable insulation • Poor return lead clamping Arc strike 4/23/2007 98 of 691
  99. 99. Miscellaneous Imperfections 3.27 Causes: • Excessive current • Damp electrodes • Contamination • Incorrect wire feed speed when welding with the MAG welding process Spatter • Arc blow 4/23/2007 99 of 691
  100. 100. Mechanical Damage 3.28 Mechanical damage can be defined as any surface material damage cause during the manufacturing process. • Grinding • Hammering • Chiselling • Chipping • Breaking off welded attachments (torn surfaces) • Using needle guns to compress weld capping runs 4/23/2007 100 of 691
  101. 101. Mechanical Damage 3.28 Chipping Marks Mechanical Damage/Grinding Mark 4/23/2007 101 of 691
  102. 102. Welding Inspector Destructive Testing Section 4 4/23/2007 102 of 691
  103. 103. Qualitative and Quantitative Tests 4.1 The following mechanical tests have units and are termed quantitative tests to measure Mechanical Properties • Tensile tests (Transverse Welded Joint, All Weld Metal) • Toughness testing (Charpy, Izod, CTOD) • Hardness tests (Brinell, Rockwell, Vickers) The following mechanical tests have no units and are termed qualitative tests for assessing joint quality • Macro testing • Bend testing • Fillet weld fracture testing • Butt weld nick-break testing 4/23/2007 104 of 691
  104. 104. Mechanical Test Samples 4.1 Tensile Specimens CTOD Specimen Bend Test Specimen Charpy Specimen Fracture Fillet Specimen 4/23/2007 105 of 691
  105. 105. Destructive Testing 4.1 WELDING PROCEDURE QUALIFICATION TESTING top of fixed pipe 2 Typical Positions for Test Pieces Specimen Type Position •Macro + Hardness 5 3 •Transverse Tensile 2, 4 •Bend Tests 2, 4 •Charpy Impact Tests 3 4 •Additional Tests 3 5 4/23/2007 106 of 691
  106. 106. Definitions Mechanical Properties of metals are related to the amount of deformation which metals can withstand under different circumstances of force application. • Malleability Ability of a material to withstand deformation • Ductility under static compressive • Toughness loading without rupture • Hardness • Tensile Strength 4/23/2007 107 of 691
  107. 107. Definitions Mechanical Properties of metals are related to the amount of deformation which metals can withstand under different circumstances of force application. • Malleability Ability of a material undergo plastic • Ductility deformation under static • Toughness tensile loading without • Hardness rupture. Measurable elongation and reduction • Tensile Strength in cross section area 4/23/2007 108 of 691
  108. 108. Definitions Mechanical Properties of metals are related to the amount of deformation which metals can withstand under different circumstances of force application. • Malleability Ability of a material to withstand bending or the • Ductility application of shear • Toughness stresses by impact loading • Hardness without fracture. • Tensile Strength 4/23/2007 109 of 691
  109. 109. Definitions Mechanical Properties of metals are related to the amount of deformation which metals can withstand under different circumstances of force application. • Malleability Measurement of a materials surface • Ductility resistance to indentation • Toughness from another material by • Hardness static load • Tensile Strength 4/23/2007 110 of 691
  110. 110. Definitions Mechanical Properties of metals are related to the amount of deformation which metals can withstand under different circumstances of force application. • Malleability Measurement of the maximum force required to • Ductility fracture a materials bar of • Toughness unit cross-sectional area in • Hardness tension • Tensile Strength 4/23/2007 111 of 691
  111. 111. Transverse Joint Tensile Test 4.2 Weld on plate Multiple cross joint Weld on pipe specimens 4/23/2007 112 of 691
  112. 112. Tensile Test 4.3 All-Weld Metal Tensile Specimen Transverse Tensile Specimen 4/23/2007 113 of 691
  113. 113. STRA (Short Transverse Reduction Area) For materials that may be subject to Lamellar Tearing 4/23/2007 114 of 691
  114. 114. UTS Tensile test 4.4 4/23/2007 115 of 691
  115. 115. Charpy V-Notch Impact Test 4.5 Objectives: • measuring impact strength in different weld joint areas • assessing resistance toward brittle fracture Information to be supplied on the test report: • Material type • Notch type • Specimen size • Test temperature • Notch location • Impact Strength Value 4/23/2007 116 of 691
  116. 116. Ductile / Brittle Transition Curve 4.6 Ductile fracture Temperature range 47 Joules Transition range Ductile/Brittle transition point 28 Joules Energy absorbed Brittle fracture - 50 - 40 - 30 - 20 - 10 0 Testing temperature - Degrees Centigrade Three specimens are normally tested at each temperature 4/23/2007 117 of 691
  117. 117. Comparison Charpy Impact Test Results 4.6 Impact Energy Joules Room Temperature -20oC Temperature 1. 197 Joules 1. 49 Joules 2. 191 Joules 2. 53 Joules 3. 186 Joules 3. 51 Joules Average = 191 Joules Average = 51 Joules The test results show the specimens carried out at room temperature absorb more energy than the specimens carried out at -20oC 4/23/2007 118 of 691
  118. 118. Charpy V-notch impact test specimen 4.7 Specimen dimensions according ASTM E23 ASTM: American Society of Testing Materials 4/23/2007 119 of 691
  119. 119. Charpy V-Notch Impact Test 4.8 Specime Pendulu n m (striker) Anvil (support) 4/23/2007 120 of 691
  120. 120. Charpy Impact Test 4.9 22.5o 2 mm 10 mm 100% Brittle Machined notch Fracture surface 8 mm 100% bright crystalline brittle fracture 100% Ductile Machined notch Large reduction in area, shear lips Randomly torn, dull gray fracture surface 4/23/2007 121 of 691
  121. 121. Hardness Testing 4.10 Definition Measurement of resistance of a material against penetration of an indenter under a constant load There is a direct correlation between UTS and hardness Hardness tests: Brinell Vickers Rockwell 4/23/2007 122 of 691
  122. 122. Hardness Testing 4.10 Objectives: • measuring hardness in different areas of a welded joint • assessing resistance toward brittle fracture, cold cracking and corrosion sensitivity within a H2S (Hydrogen Sulphide) environment. Information to be supplied on the test report: • material type • location of indentation • type of hardness test and load applied on the indenter • hardness value 4/23/2007 123 of 691
  123. 123. Vickers Hardness Test 4.11 Vickers hardness tests: indentation body is a square based diamond pyramid (136º included angle) the average diagonal (d) of the impression is converted to a hardness number from a table it is measured in HV5, HV10 or HV025 Adjustable Diamond Indentation shutters indentor 4/23/2007 124 of 691
  124. 124. Vickers Hardness Test Machine 4.11 4/23/2007 125 of 691
  125. 125. Brinell Hardness Test 4.11 • Hardened steel ball of given diameter is subjected for a given time to a given load • Load divided by area of indentation gives Brinell hardness in kg/mm2 • More suitable for on site hardness testing 30KN Ø=10mm steel ball 4/23/2007 126 of 691
  126. 126. Rockwell Hardness Test Rockwell B Rockwell C 1KN 1.5KN Ø=1.6mm 120 Diamond steel ball Cone 4/23/2007 127 of 691
  127. 127. Hardness Testing 4.12 usually the hardest region 1.5 to 3mm fusion line or fusion HAZ boundary Hardness Test Methods Typical Designations Vickers 240 HV10 Rockwell Rc 22 Brinell 200 BHN-W Hardness specimens can also be used for CTOD samples 4/23/2007 128 of 691
  128. 128. Crack Tip Opening Displacement testing 4.12 • Test is for fracture toughness • Square bar machined with a notch placed in the centre. • Tested below ambient temperature at a specified temperature. • Load is applied at either end of the test specimen in an attempt to open a crack at the bottom of the notch • Normally 3 samples 4/23/2007 129 of 691
  129. 129. Fatigue Fracture 4.13 Location: Any stress concentration area Steel Type: All steel types Susceptible Microstructure: All grain structures Test for Fracture Toughness is CTOD (Crack Tip Opening Displacement) 4/23/2007 130 of 691
  130. 130. Fatigue Fracture 4.13 • Fatigue cracks occur under cyclic stress conditions • Fracture normally occurs at a change in section, notch and weld defects i.e stress concentration area • All materials are susceptible to fatigue cracking • Fatigue cracking starts at a specific point referred to as a initiation point • The fracture surface is smooth in appearance sometimes displaying beach markings • The final mode of failure may be brittle or ductile or a combination of both 4/23/2007 131 of 691
  131. 131. Fatigue Fracture Precautions against Fatigue Cracks • Toe grinding, profile grinding. • The elimination of poor profiles • The elimination of partial penetration welds and weld defects • Operating conditions under the materials endurance limits • The elimination of notch effects e.g. mechanical damage cap/root undercut • The selection of the correct material for the service conditions of the component 4/23/2007 132 of 691
  132. 132. Fatigue Fracture Fatigue fracture occurs in structures subject to repeated application of tensile stress. Crack growth is slow (in same cases, crack may grow into an area of low stress and stop without failure). 4/23/2007 133 of 691
  133. 133. Fatigue Fracture Secondary mode of failure Fatigue fracture surface ductile fracture rough fibrous appearance smooth in appearance Initiation points / weld defects 4/23/2007 134 of 691
  134. 134. Fatigue Fracture Fatigue fracture distinguish features: • Crack growth is slow • It initiate from stress concentration points • load is considerably below the design or yield stress level • The surface is smooth • The surface is bounded by a curve • Bands may sometimes be seen on the smooth surface –”beachmarks”. They show the progress of the crack front from the point of origin • The surface is 90° to the load • Final fracture will usually take the form of gross yielding (as the maximum stress in the remaining ligament increase!) • Fatigue crack need initiation + propagation periods 4/23/2007 135 of 691
  135. 135. Bend Tests 4.15 Object of test: • To determine the soundness of the weld zone. Bend testing can also be used to give an assessment of weld zone ductility. • There are three ways to perform a bend test: Face bend Root bend Side bend Side bend tests are normally carried out on welds over 12mm in thickness 4/23/2007 136 of 691
  136. 136. Bending test 4.16 Types of bend test for welds (acc. BS EN 910): “t” up to 12 mm Root / face bend Thickness of material - “t” “t” over 12 mm Side bend 4/23/2007 137 of 691
  137. 137. Fillet Weld Fracture Tests 4.17 Object of test: • To break open the joint through the weld to permit examination of the fracture surfaces • Specimens are cut to the required length • A saw cut approximately 2mm in depth is applied along the fillet welds length • Fracture is usually made by striking the specimen with a single hammer blow • Visual inspection for defects 4/23/2007 138 of 691
  138. 138. Fillet Weld Fracture Tests 4.17 Hammer 2mm Notch Fracture should break weld saw cut to root 4/23/2007 139 of 691
  139. 139. Fillet Weld Fracture Tests 4.17 This fracture indicates This fracture has lack of fusion occurred saw cut to root Lack of Penetration 4/23/2007 140 of 691
  140. 140. Nick-Break Test 4.18 Object of test: • To permit evaluation of any weld defects across the fracture surface of a butt weld. • Specimens are cut transverse to the weld • A saw cut approximately 2mm in depth is applied along the welds root and cap • Fracture is usually made by striking the specimen with a single hammer blow • Visual inspection for defects 4/23/2007 141 of 691
  141. 141. Nick-Break Test 4.18 Notch cut by hacksaw 2 mm 19 mm 2 mm Approximately 230 mm Weld reinforcement may or may not be removed 4/23/2007 142 of 691
  142. 142. Nick Break Test 4.18 Alternative nick-break test specimen, notch applied all way around the specimen Lack of root penetration Inclusions on fracture or fusion line 4/23/2007 143 of 691
  143. 143. Summary of Mechanical Testing 4.19 We test welds to establish minimum levels of mechanical properties, and soundness of the welded joint We divide tests into Qualitative & Quantitative methods: Quantitative: (Have units/numbers) Qualitative: (Have no units/numbers) To measure mechanical properties For assessing joint quality Hardness (VPN & BHN) Macro tests Toughness (Joules & ft.lbs) Bend tests Strength (N/mm2 & PSI, MPa) Fillet weld fracture tests Ductility / Elongation (E%) Butt Nick break tests 4/23/2007 144 of 691
  144. 144. Welding Inspector WPS – Welder Qualifications Section 5 4/23/2007 145 of 691
  145. 145. Welding Procedure Qualification 5.1 Question: What is the main reason for carrying out a Welding Procedure Qualification Test ? (What is the test trying to show ?) Answer: To show that the welded joint has the properties* that satisfy the design requirements (fit for purpose) * properties •mechanical properties are the main interest - always strength but toughness & hardness may be important for some applications •test also demonstrates that the weld can be made without defects 4/23/2007 146 of 691
  146. 146. Welding Procedures 5.1 Producing a welding procedure involves: • Planning the tasks • Collecting the data • Writing a procedure for use of for trial • Making a test welds • Evaluating the results • Approving the procedure • Preparing the documentation 4/23/2007 147 of 691
  147. 147. Welding Procedures 5.2 In most codes reference is made to how the procedure are to be devised and whether approval of these procedures is required. The approach used for procedure approval depends on the code: Example codes: • AWS D.1.1: Structural Steel Welding Code • BS 2633: Class 1 welding of Steel Pipe Work • API 1104: Welding of Pipelines • BS 4515: Welding of Pipelines over 7 Bar Other codes may not specifically deal with the requirement of a procedure but may contain information that may be used in writing a weld procedure • EN 1011Process of Arc Welding Steels 4/23/2007 148 of 691
  148. 148. Welding Procedure Qualification 5.3 (according to EN ISO 15614) The welding engineer writes qualified Welding Procedure Specifications (WPS) for production welding Production welding conditions must remain within the range of qualification allowed by the WPQR 4/23/2007 149 of 691
  149. 149. Welding Procedure Qualification 5.3 (according to EN Standards) welding conditions are called welding variables welding variables are classified by the EN ISO Standard as: •Essential variables •Non-essential variables •Additional variables Note: additional variables = ASME supplementary essential The range of qualification for production welding is based on the limits that the EN ISO Standard specifies for essential variables* (* and when applicable - the additional variables) 4/23/2007 150 of 691
  150. 150. Welding Procedure Qualification 5.3 (according to EN Standards) WELDING ESSENTIAL VARIABLES Question: Why are some welding variables classified as essential ? Answer: A variable, that if changed beyond certain limits (specified by the Welding Standard) may have a significant effect on the properties* of the joint * particularly joint strength and ductility 4/23/2007 151 of 691
  151. 151. Welding Procedure Qualification 5.3 (according to EN Standards) SOME TYPICAL ESSENTIAL VARIABLES • Welding Process • Post Weld Heat Treatment (PWHT) • Material Type • Electrode Type, Filler Wire Type (Classification) • Material Thickness • Polarity (AC, DC+ve / DC-ve) • Pre-Heat Temperature • Heat Input • Welding Position 4/23/2007 152 of 691
  152. 152. Welding Procedures 5.3 Components of a welding procedure Parent material • Type (Grouping) • Thickness • Diameter (Pipes) • Surface condition) Welding process • Type of process (MMA, MAG, TIG, SAW etc) • Equipment parameters • Amps, Volts, Travel speed Welding Consumables • Type of consumable/diameter of consumable • Brand/classification • Heat treatments/ storage 4/23/2007 153 of 691
  153. 153. Welding Procedures 5.3 Components of a welding procedure Joint design •Edge preparation •Root gap, root face •Jigging and tacking •Type of baking Welding Position •Location, shop or site •Welding position e.g. 1G, 2G, 3G etc •Any weather precaution Thermal heat treatments •Preheat, temps •Post weld heat treatments e.g. stress relieving 4/23/2007 154 of 691
  154. 154. Welding Procedures 5.3 Object of a welding procedure test To give maximum confidence that the welds mechanical and metallurgical properties meet the requirements of the applicable code/specification. Each welding procedure will show a range to which the procedure is approved (extent of approval) If a customer queries the approval evidence can be supplied to prove its validity 4/23/2007 155 of 691
  155. 155. Welding Procedures Summary of designations: pWPS: Preliminary Welding Procedure Specification (Before procedure approval) WPAR (WPQR): Welding Procedure Approval Record (Welding procedure Qualification record) WPS: Welding Procedure Specification (After procedure approval) 4/23/2007 156 of 691
  156. 156. Example: Welding Procedure Specification (WPS) 4/23/2007 157 of 691
  157. 157. Welder Qualification 5.4 Numerous codes and standards deal with welder qualification, e.g. BS EN 287. • Once the content of the procedure is approved the next stage is to approve the welders to the approved procedure. • A welders test know as a Welders Qualification Test (WQT). Object of a welding qualification test: • To give maximum confidence that the welder meets the quality requirements of the approved procedure (WPS). • The test weld should be carried out on the same material and same conditions as for the production welds. 4/23/2007 158 of 691
  158. 158. Welder Qualification 5.4 & 5.5 (according to EN Standards) Question: What is the main reason for qualifying a welder ? Answer: To show that he has the skill to be able to make production welds that are free from defects Note: when welding in accordance with a Qualified WPS 4/23/2007 159 of 691
  159. 159. Welder Qualification (according to EN 287 ) 5.5 The welder is allowed to make production welds within the range of qualification shown on the Certificate The range of qualification allowed for production welding is based on the limits that the EN Standard specifies for the welder qualification essential variables A Certificate may be withdrawn by the Employer if there is reason to doubt the ability of the welder, for example • a high repair rate • not working in accordance with a qualified WPS The qualification shall remain valid for 2 years provided there is certified confirmation of welding to the WPS in that time. A Welder‟s Qualification Certificate automatically expires if the welder has not used the welding process for 6 months or longer. 4/23/2007 160 of 691
  160. 160. Welding Procedure Qualification 5.7 (according to EN ISO 15614) Welding Engineer writes a preliminary Welding Procedure Specification (pWPS) for each test weld to be made • A welder makes a test weld in accordance with the pWPS • A welding inspector records all the welding conditions used for the test weld (referred to as the „as-run‟ conditions) An Independent Examiner/ Examining Body/ Third Party inspector may be requested to monitor the qualification process The finished test weld is subjected to NDT in accordance with the methods specified by the EN ISO Standard - Visual, MT or PT & RT or UT 4/23/2007 161 of 691
  161. 161. Welding Procedure Qualification 5.7 (according to EN ISO 15614) Test weld is subjected to destructive testing (tensile, bend, macro) The Application Standard, or Client, may require additional tests such as impact tests, hardness tests (and for some materials - corrosion tests) A Welding Procedure Qualification Record (WPQR) is prepared giving details of: - • The welding conditions used for the test weld • Results of the NDT • Results of the destructive tests • The welding conditions that the test weld allows for production welding The Third Party may be requested to sign the WPQR as a true record 4/23/2007 162 of 691
  162. 162. Welder Qualification 5.9 (according to EN 287 ) An approved WPS should be available covering the range of qualification required for the welder approval. • The welder qualifies in accordance with an approved WPS • A welding inspector monitors the welding to make sure that the welder uses the conditions specified by the WPS EN Welding Standard states that an Independent Examiner, Examining Body or Third Party Inspector may be required to monitor the qualification process 4/23/2007 163 of 691
  163. 163. Welder Qualification 5.9 (according to EN 287 ) The finished test weld is subjected to NDT by the methods specified by the EN Standard - Visual, MT or PT & RT or UT The test weld may need to be destructively tested - for certain materials and/or welding processes specified by the EN Standard or the Client Specification • A Welder‟s Qualification Certificate is prepared showing the conditions used for the test weld and the range of qualification allowed by the EN Standard for production welding • The Qualification Certificate is usually endorsed by a Third Party Inspector as a true record of the test 4/23/2007 164 of 691
  164. 164. Welder Qualification 5.10 Information that should be included on a welders test certificate are, which the welder should have or have access to a copy of ! • Welders name and identification number • Date of test and expiry date of certificate • Standard/code e.g. BS EN 287 • Test piece details • Welding process. • Welding parameters, amps, volts • Consumables, flux type and filler classification details • Sketch of run sequence • Welding positions • Joint configuration details • Material type qualified, pipe diameter etc • Test results, remarks • Test location and witnessed by • Extent (range) of approval 4/23/2007 165 of 691
  165. 165. Welding Inspector Materials Inspection Section 6 4/23/2007 167 of 691
  166. 166. Material Inspection One of the most important items to consider is Traceability. The materials are of little use if we can not, by use of an effective QA system trace them from specification and purchase order to final documentation package handed over to the Client. All materials arriving on site should be inspected for: • Size / dimensions • Condition • Type / specification In addition other elements may need to be considered depending on the materials form or shape 4/23/2007 168 of 691
  167. 167. Pipe Inspection We inspect the condition (Corrosion, Damage, Wall thickness Ovality, Laminations & Seam) Specification LP5 Welded Size seam Other checks may need to be made such as: distortion tolerance, number of plates and storage. 4/23/2007 169 of 691
  168. 168. Plate Inspection We inspect the condition (Corrosion, Mechanical damage, Laps, Bands & Laminations) Specification 5L Size Other checks may need to be made such as: distortion tolerance, number of plates and storage. 4/23/2007 170 of 691
  169. 169. Parent Material Imperfections Mechanical damage Lap Lamination Segregation line Laminations are caused in the parent plate by the steel making process, originating from ingot casting defects. Segregation bands occur in the centre of the plate and are low melting point impurities such as sulphur and phosphorous. Laps are caused during rolling when overlapping metal does not fuse to the base material. 4/23/2007 171 of 691
  170. 170. Lapping 4/23/2007 172 of 691
  171. 171. Lamination 4/23/2007 173 of 691
  172. 172. Laminations Plate Lamination 4/23/2007 174 of 691
  173. 173. Welding Inspector Codes & Standards Section 7 4/23/2007 175 of 691
  174. 174. Codes & Standards The 3 agencies generally identified in a code or standard: The customer, or client The manufacturer, or contractor The 3rd party inspection, or clients representative Codes often do not contain all relevant data, but may refer to other standards 4/23/2007 176 of 691
  175. 175. Standard/Codes/Specifications STANDARDS SPECIFICATIONS CODES Examples Examples plate, pipe pressure vessels forgings, castings bridges valves pipelines electrodes tanks 4/23/2007 177 of 691
  176. 176. Welding Inspector Welding Symbols Section 8 4/23/2007 178 of 691
  177. 177. Weld symbols on drawings Advantages of symbolic representation: • simple and quick plotting on the drawing • does not over-burden the drawing • no need for additional view • gives all necessary indications regarding the specific joint to be obtained Disadvantages of symbolic representation: • used only for usual joints • requires training for properly understanding of symbols 4/23/2007 179 of 691
  178. 178. Weld symbols on drawings The symbolic representation includes: • an arrow line • a reference line • an elementary symbol The elementary symbol may be completed by: • a supplementary symbol • a means of showing dimensions • some complementary indications 4/23/2007 180 of 691
  179. 179. Dimensions Convention of dimensions In most standards the cross sectional dimensions are given to the left side of the symbol, and all linear dimensions are give on the right side BS EN ISO 22553 a = Design throat thickness s = Depth of Penetration, Throat thickness z = Leg length (min material thickness) AWS A2.4 •In a fillet weld, the size of the weld is the leg length •In a butt weld, the size of the weld is based on the depth of the joint preparation 4/23/2007 181 of 691
  180. 180. Weld symbols on drawings A method of transferring information from the design office to the workshop is: Please weld here The above information does not tell us much about the wishes of the designer. We obviously need some sort of code which would be understood by everyone. Most countries have their own standards for symbols. Some of them are AWS A2.4 & BS EN 22553 (ISO 2553) 4/23/2007 182 of 691
  181. 181. Weld symbols on drawings Joints in drawings may be indicated: •by detailed sketches, showing every dimension •by symbolic representation 4/23/2007 183 of 691
  182. 182. Elementary Welding Symbols (BS EN ISO 22553 & AWS A2.4) Convention of the elementary symbols: Various categories of joints are characterised by an elementary symbol. The vertical line in the symbols for a fillet weld, single/double bevel butts and a J-butt welds must always be on the left side. Weld type Sketch Symbol Square edge butt weld Single-v butt weld 4/23/2007 184 of 691
  183. 183. Elementary Welding Symbols Weld type Sketch Symbol Single-V butt weld with broad root face Single bevel butt weld Single bevel butt weld with broad root face Backing run 4/23/2007 185 of 691
  184. 184. Elementary Welding Symbols Weld type Sketch Symbol Single-U butt weld Single-J butt weld Surfacing Fillet weld 4/23/2007 186 of 691
  185. 185. ISO 2553 / BS EN 22553 Plug weld Square Butt weld Resistance spot weld Steep flanked Single-V Butt Resistance seam weld Surfacing 4/23/2007 187 of 691
  186. 186. Arrow Line (BS EN ISO 22553 & AWS A2.4): Convention of the arrow line: • Shall touch the joint intersection • Shall not be parallel to the drawing • Shall point towards a single plate preparation (when only one plate has preparation) 4/23/2007 188 of 691
  187. 187. Reference Line (AWS A2.4) Convention of the reference line: Shall touch the arrow line Shall be parallel to the bottom of the drawing 4/23/2007 189 of 691
  188. 188. Reference Line (BS EN ISO 22553) Convention of the reference line: • Shall touch the arrow line • Shall be parallel to the bottom of the drawing • There shall be a further broken identification line above or beneath the reference line (Not necessary where the weld is symmetrical!) or 4/23/2007 190 of 691
  189. 189. Double side weld symbols (BS EN ISO 22553 & AWS A2.4) Convention of the double side weld symbols: Representation of welds done from both sides of the joint intersection, touched by the arrow head Fillet weld Double bevel Double J Double V Double U 4/23/2007 191 of 691
  190. 190. ISO 2553 / BS EN 22553 Reference lines Arrow line Other side Arrow side Arrow side Other side 4/23/2007 192 of 691
  191. 191. ISO 2553 / BS EN 22553 MR M Single-V Butt with Single-U Butt with permanent backing strip removable backing strip Single-V Butt flush cap Single-U Butt with sealing run 4/23/2007 193 of 691
  192. 192. ISO 2553 / BS EN 22553 Single-bevel butt Double-bevel butt Single-bevel butt Single-J butt 4/23/2007 194 of 691
  193. 193. ISO 2553 / BS EN 22553 s10 10 15 Partial penetration single-V butt „S‟ indicates the depth of penetration 4/23/2007 195 of 691
  194. 194. ISO 2553 / BS EN 22553 a = Design throat thickness s = Depth of Penetration, Throat thickness z = Leg length(min material thickness) a = (0.7 x z) a4 a z s 4mm Design throat z6 s6 6mm leg 6mm Actual throat 4/23/2007 196 of 691
  195. 195. ISO 2553 / BS EN 22553 Arrow side Arrow side 4/23/2007 197 of 691
  196. 196. ISO 2553 / BS EN 22553 s6 6mm fillet weld Other side s6 Other side 4/23/2007 198 of 691
  197. 197. ISO 2553 / BS EN 22553 n = number of weld elements l = length of each weld element (e) = distance between each weld element n x l (e) Welds to be staggered 2 x 40 (50) 111 3 x 40 (50) Process 4/23/2007 199 of 691
  198. 198. ISO 2553 / BS EN 22553 All dimensions in mm z5 3 x 80 (90) z6 3 x 80 (90) 5 80 80 80 5 6 90 90 90 6 4/23/2007 200 of 691
  199. 199. ISO 2553 / BS EN 22553 All dimensions in mm z8 3 x 80 (90) z6 3 x 80 (90) 6 80 80 80 6 8 90 90 90 8 4/23/2007 201 of 691
  200. 200. Supplementary symbols (BS EN ISO 22553 & AWS A2.4) Convention of supplementary symbols Supplementary information such as welding process, weld profile, NDT and any special instructions Toes to be ground smoothly (BS EN only) Site Weld Concave or Convex Weld all round 4/23/2007 202 of 691
  201. 201. Supplementary symbols (BS EN ISO 22553 & AWS A2.4) Convention of supplementary symbols Supplementary information such as welding process, weld profile, NDT and any special instructions Ground flush 111 MR M Removable Permanent Welding process backing strip backing strip numerical BS EN Further supplementary information, such as WPS number, or NDT may be placed in the fish tail 4/23/2007 203 of 691
  202. 202. ISO 2553 / BS EN 22553 a b c d 4/23/2007 204 of 691
  203. 203. ISO 2553 / BS EN 22553 Mitre Convex Toes Concave shall be blended 4/23/2007 205 of 691
  204. 204. ISO 2553 / BS EN 22553 a = Design throat thickness s = Depth of Penetration, Throat thickness z = Leg length(min material thickness) a = (0.7 x z) a4 a z s 4mm Design throat z6 s6 6mm leg 6mm Actual throat 4/23/2007 206 of 691
  205. 205. ISO 2553 / BS EN 22553 Complimentary Symbols Field weld (site weld) Welding to be carried out all round component (peripheral weld) NDT WPS The component requires Additional information, NDT inspection the reference document is included in the box 4/23/2007 207 of 691
  206. 206. ISO 2553 / BS EN 22553 Numerical Values for Welding Processes: 111: MMA welding with covered electrode 121: Sub-arc welding with wire electrode 131: MIG welding with inert gas shield 135: MAG welding with non-inert gas shield 136: Flux core arc welding 141: TIG welding 311: Oxy-acetylene welding 72: Electro-slag welding 15: Plasma arc welding 4/23/2007 208 of 691
  207. 207. AWS A2.4 Welding Symbols 4/23/2007 209 of 691
  208. 208. AWS Welding Symbols Depth of Root Opening Bevel 1(1-1/8) 1/8 60o Effective Groove Angle Throat 4/23/2007 210 of 691
  209. 209. AWS Welding Symbols Welding Process GSFCAW 1(1-1/8) 1/8 60o GMAW GTAW SAW 4/23/2007 211 of 691
  210. 210. AWS Welding Symbols Welds to be staggered 3 – 10 SMAW 3 – 10 Process 3 3 10 4/23/2007 212 of 691
  211. 211. AWS Welding Symbols 3rd Operation Sequence of Operations 2nd Operation 1st Operation FCAW 1(1-1/8) 1/8 60o 4/23/2007 213 of 691
  212. 212. AWS Welding Symbols RT Sequence of Operations MT MT FCAW 1(1-1/8) 1/8 60o 4/23/2007 214 of 691
  213. 213. AWS Welding Symbols Dimensions- Leg Length 6 leg on member A 6/8 Member A 6 8 Member B 4/23/2007 215 of 691
  214. 214. Welding Inspector Intro To Welding Processes Section 9 4/23/2007 221 of 691
  215. 215. Welding Processes Welding is regarded as a joining process in which the work pieces are in atomic contact Pressure welding Fusion welding • Forge welding • Oxy-acetylene • Friction welding • MMA (SMAW) • Resistance Welding • MIG/MAG (GMAW) • TIG (GTAW) • Sub-arc (SAW) • Electro-slag (ESW) • Laser Beam (LBW) • Electron-Beam (EBW) 4/23/2007 222 of 691

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