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1998 VIW-1
VISUAL INSPECTION WORKSHOP Introduction
Review Slides - Introduction Review AWS B1.10, B1.11, and VIW Manual Examine Metal Weld Samples Review AWS Part B Specification Review Plastic Weld Replicas Practice Use of Hand Tools Practice Exercise and Review Practical Exam and Review
1998 VIW-2
VISUAL INSPECTION WORKSHOP Introduction
Visual Inspection (VT) is the Basic Element of any Quality Control System. It must be done, however, by Trained Personnel.
1998 VIW-3
VISUAL INSPECTION WORKSHOP Introduction
“It has been shown repeatedly that an effective program of Visual Inspection (VT), conducted by properly trained personnel, will result in the discovery of the vast majority of those defects which would otherwise be discovered later by some more expensive nondestructive test method.”
1998 VIW-4
VISUAL INSPECTION WORKSHOP Introduction
While VT is limited to the visible, external surfaces only, it should be recognized that the external surfaces
of the components most often see the highest stresses in service, and are most often the more critical portions of the components.
1998 VIW-5
VISUAL INSPECTION WORKSHOP Introduction
VT Is Very Cost Effective ….
Relatively Simple To Perform Minimal Equipment Required Problems Found As They Occur Early Repairs Easier To Accomplish
1998 VIW-6
VISUAL INSPECTION WORKSHOP Introduction
For Welding Inspection, VT Must Be Applied:
Before Welding During Welding After Welding
1998 VIW-7
VISUAL INSPECTION WORKSHOP Introduction
Organizing The Inspection Effort …. Become Familiar w/ Welding Requirements Specify Timing for Inspections Develop Appropriate ‘Hold Points’ Develop Applicable VT Techniques Develop Repair/Re-Inspection Procedures Develop Procedure for Reports and
Maintenance of Records
1998 VIW-8
VISUAL INSPECTION WORKSHOP Introduction
Hold Points -
Points in the Fabrication Sequence where Inspection must be Performed Before Fabrication can continue.
1998 VIW-9
VISUAL INSPECTION WORKSHOP Introduction
Applying The Inspection Effort ‘Before’…. Welding Equipment - Type, Suitability Filler Metals - Type, Storage, Size Weld Joint Cleanliness Weld Joint Fitup - Bevels, Faces, RO, etc. Preheat Requirements Others
1998 VIW-10
VISUAL INSPECTION WORKSHOP Introduction
Applying The Inspection Effort ‘During’…. Tack Weld Quality - Feathering Root Pass Quality - Size Intermediate Pass Cleaning Gouging to Remove Defects Distortion Preheat/Interpass Temp. Maintenance
1998 VIW-11
VISUAL INSPECTION WORKSHOP Introduction
Applying The Inspection Effort ‘After’…. Final Pass Cleaning, Finishing Weld Sizes Post-Weld Heat Treatment Distortion & Final Dimensions Other NDE Reports
1998 VIW-12
VISUAL INSPECTION WORKSHOP AWS B1.10
Review B1.10 - NDE of Welds
Table 1, Discontinuities (page 3) Figures (pages 4-9) Terminology (pages 10-12) Table 2 (page 13) NDE, Tables 3 & 4 (pages 15-28) Appendices (pages 29-34)
1998 VIW-13
Radiographs
Incomplete Joint Penetration
1998 VIW-14
Radiographs
Incomplete Joint Penetration
1998 VIW-15
Radiographs
Incomplete Joint Penetration
1998 VIW-16
Radiographs
Undercut - Should find Visually, not on RT
1998 VIW-17
Radiographs
Scattered Porosity
1998 VIW-18
Radiographs
Elongated Porosity (Wormhole)
1998 VIW-19
Radiographs
Slag Lines
1998 VIW-20
Radiographs
Slag Lines on Root Pass Face
1998 VIW-21
Radiographs
Tungsten Inclusions
1998 VIW-22
Radiographs
Incomplete Fusion (Severe)
1998 VIW-23
Radiographs
Longitudinal Crack
1998 VIW-24
Radiographs
Transverse Crack
1998 VIW-25
Radiographs
Transverse Cracks
1998 VIW-26
Radiographs
Pipe - Socket Welds (Stand Off)
1998 VIW-27
Radiographs
Pipe - Double Wall - Elliptical
1998 VIW-28
Radiographs
Pipe Elbow - Double Wall - Elliptical
1998 VIW-29
Radiographs
Pipe Branch and Butt Welds
1998 VIW-30
VISUAL INSPECTION WORKSHOP AWS B1.11
Review B1.11 - VT of Welds Weld Discontinuity Figures (pages 5-21) Visual Inspection Aids (pages 22-27) Appendix A - Technical Society Contacts
(page 29) Appendix B - Supplementary Reading List
1998 VIW-31
VISUAL INSPECTION WORKSHOP Amps, Arc Length,
Travel Speed
SMAW Welds
A - Proper parameters
B - Amps too low
C - Amps too high
D - Arc length too short
E - Arc length too long
F - Travel speed too slow
G - Travel speed too fast
1998 VIW-32
VISUAL INSPECTION WORKSHOP VIW Reference
Manual
VIW Reference Manual - Self-Study review for NDE and Tool usage
Mod 1 Visual Inspection Mod 2 NDE (review Figures) Mod 3 Weld Discontinuities Mod 4 Part B Specification
(review actual Part B Spec) Mod 5 Measurements (review tool
use)
1998 VIW-33
VISUAL INSPECTION WORKSHOP Metal Weld
Samples
Examine Metal Welds and Note Discontinuities on Notepad
Review Results
1998 VIW-34
VISUAL INSPECTION WORKSHOP AWS Part B
Specification
Review Part B Specification in Detail
Table of Contents Conversion Table and SI Prefixes Appendices and Usage Footnotes and Tolerances (e.g. underrun)
1998 VIW-35
VISUAL INSPECTION WORKSHOP Plastic Weld
Replicas
Review Each Type of Weld Replica
(Fillet A and B, Large and Small T-Joints, Bend Tests, Tensile Samples)
Must be able to identify each type Measure correct Weld and Zone
(eg - Fillet A, Side 3, Zone 0-1)
1998 VIW-36
VISUAL INSPECTION WORKSHOP Hand Tool Kit
Demonstrate Use of Each Tool
6 inch Rule 1 inch Micrometer Metric Dial Caliper Palmgren Gage Undercut Gage Fillet Weld Gages
1998 VIW-37
VISUAL INSPECTION WORKSHOP Six Inch
Machinist’s Scale
Accuracy to 1/64” or about 15 mils, 0.015”
Align vertically on part, not flat, for best accuracy
Best to measure starting from the 1” mark rather than the end, which may be worn, but don’t forget to subtract the 1” from result!
1998 VIW-38
VISUAL INSPECTION WORKSHOP
1 Inch Micrometer Clean jaw faces, close Zero Micrometer or, Use ‘Tare’ Approach.
If Micrometer ‘zeroes’ at a plus 0.003, take measurement of parts and subtract the 0.003 from result; (converse if it ‘zeroes’ a minus.)
1998 VIW-39
VISUAL INSPECTION WORKSHOP
1 Inch Micrometer
Accuracy to plus or minus 1 mil, 0.001”
Each small, unmarked thimble division equals 1 mil
Can estimate to nearest 1/2 mil, 0.0005
1998 VIW-40
VISUAL INSPECTION WORKSHOP
1 Inch Micrometer
One complete thimble rotation equals 25 mils, or 0.025 inches.
Four complete thimble rotations equals 100 mils, or 0.100 inches
1998 VIW-41
VISUAL INSPECTION WORKSHOP Metric Dial Caliper Accuracy to 0.1 mm,
or about 4 mils Can estimate to
nearest 0.05 mm, or about 2 mils
Some calipers have both metric and U.S. Customary scales but SI only for Exam
1998 VIW-42
VISUAL INSPECTION WORKSHOP Palmgren Gage
Only use to measure height of groove weld reinforcement.
Don’t use for measuring fillet weld sizes since plastic welds are too small to do accurately.
Rotate ‘legs’ of gage to just touch toes of weld for best accuracy
1998 VIW-43
VISUAL INSPECTION WORKSHOP V-WAC Undercut
Gage - 1 of 2
Accuracy is 1/64”, or about 15 mils Calibrate on flat, smooth surface Position on weld, rotate sharp point into
undercut, read scale at other end Can measure porosity depth, but not diameter
1998 VIW-44
VISUAL INSPECTION WORKSHOP V-WAC Undercut
Gage - 2 of 2
Measures undercut up to 1/4 inch depth in 64ths of an inch
Also can be used to measure weld reinforcement height up to 1/4 inch in 64ths of an inch
1998 VIW-45
VISUAL INSPECTION WORKSHOP Fillet Weld Gage
Use Determine if Weld is Concave or Convex Pick Appropriate Gage Type - 2 types Scribed Lines on Gages for Estimating Size
of Adjacent leg Measure Smallest Weld Size Location Measure Both Legs for Convex welds Gages from 1/8” to 1/2” - 1/16” increments Gages from 1/2” to 1” - 1/8” increments
1998 VIW-46
VISUAL INSPECTION WORKSHOP Fillet Weld Shapes
Three Weld Shape Options:
Convex - use convex gage only - minimum leg size
Concave - use concave gage only - throat size
Flat - either gage type will give accurate result
1998 VIW-47
VISUAL INSPECTION WORKSHOP Convex Fillet Weld
Gage Use - 1 of 3 Determine shape of fillet
weld, select convex gage Use scribed lines on gage
for estimating size of second leg, or:
For convex welds, measure both legs for best accuracy; select minimum leg as size
1998 VIW-48
VISUAL INSPECTION WORKSHOP Convex Fillet Weld
Gage Use - 2 of 3
Measure both legs Weld size is the
lesser of the two legs for convex welds
Weld size shown is 3/8, not 1/2
1/2"
3/8"
1998 VIW-49
VISUAL INSPECTION WORKSHOP Convex Fillet Weld
Gage Use - 3 of 3
Use Correct Size Gage Too Large
Correct Gage
Too Small
5/8"
1/2"
7/16"
1998 VIW-50
VISUAL INSPECTION WORKSHOP Concave Fillet
Weld Gage Use - 1 of 2 Determine type of fillet
weld, select concave gage
Use scribed lines on gage for estimating size of weld legs if needed
On concave welds, insure 3-point contact between gage and weld
1998 VIW-51
VISUAL INSPECTION WORKSHOP Concave Fillet
Weld Gage Use - 2 of 2
Use Correct Size Gage Too Large
Correct - 3 point contact
Too Small
7/16"
5/16"
3/16"
1998 VIW-52
VISUAL INSPECTION WORKSHOP Student Hands-On
Tool Practice
Measure the Following and Note Results:
Width of 6 inch scale in mm & mils Thickness of 6 inch scale in mm & mils Thickness of Palmgren Gage in mm & mils Thickness of Fillet Gage in mm & mils Outside Diameter of Mag. Glass in mm
Review Student Results for Accuracy
1998 VIW-53
VISUAL INSPECTION WORKSHOP Practice Exercises
Complete 20 question VIW Practice Exercises using tensile, weld replicas
Review answers
1998 VIW-54
VISUAL INSPECTION WORKSHOP Practice
Examination
Complete VIW Practice Exam - 2 to 2 1/2 hours; (Student should jot down page number from Part B where answers are found to aid exam review)
Review Answers