accurate inspections nace 2013
DESCRIPTION
Accurate Inspections NACE 2013TRANSCRIPT
NACE RMS 2013 Billy J Fields
• Accurate Inspections,
LLC
o AWS CWI #03071341
o AWS CWS #0902004S
o NACE Level III CCI
#7866
o 34 Years Steel Water
Pipe Manufacturing &
Installation Experience
1
NACE RMS 2013 Discussion Topics
• Coating Purpose
• Premature Coating Failure
• Different Welding Processes & Electrodes
• NACE SP0178 Design, Fabrication, & Surface Finish Practice for Tanks & Vessels to Be Lined for Immersion Services
• SP0188 & SP0274 Holiday Testing Standards
NACE RMS 2013 Purpose of Coatings
• Safety – Protects structures that
support extreme weight
• Appearance – Pealing coatings and rusting
steel are typically an eyesore
• Cost – Cost of painting/repainting a
structure is expensive, but certainly more economical then replacing
NACE RMS 2013
Purpose of Coatings
• First line of defense to stop corrosion of a material, usually a metal.
• Acts as a barrier to prevent chemical compounds or corrosion current from contacting the substrate
NACE RMS 2013
• Premature Coating Failure
– Failed at Weld Seams
– Laps Not Sealed
– Holiday Tested????
NACE RMS 2013
• Premature Coating Failure
– Faying Surface Not Sealed
– Weld Seams Not Strip Coated
– Single Sided Weldments
NACE RMS 2013
• Skip Welds and Lap type joints are difficult to protect
NACE RMS 2013
Premature Coating Failure
• Weld Spatter Not Removed
NACE RMS 2013
• NACE SP0178
– Surface weld quality may differ from welding codes
– Remove weld spatter
– Small amounts of porosity/undercut allowed depending on degree of preparation
– Grind rough welds smooth
• ASME/AWS
– AWS/ASME have allowances for weld defects that are not allowed by SP0178
– Weld Spatter not necessarily rejectable
– Small amounts of undercut allowed
– Rough welds not necessarily rejectable
NACE RMS 2013
• NACE SP0178 – For Immersion Service – No Skip Welds
– No Laps
– Round all sharp edges
– No Arc Strikes
● Most Welding Inspectors are not aware of NACE SP0178
• ASME/AWS – Minimizes distortion from
welding process
– Laps are part of design
– Arc Strikes are not allowed
NACE RMS 2013
• NACE SP0178
– Appendix A, Figure A1
• NACE SP0178
– Appendix A, Figure A2 & A3
NACE RMS 2013
• NACE SP0178
– Appendix A, Figure A5 & A6
• NACE SP0178
– Appendix A, Figure A7 & A8
NACE RMS 2013
• NACE SP0178-2007 Appendix C
NACE RMS 2013
NACE SP0178-2007 Visual Comparator
NACE RMS 2013
• Unacceptable weld & edge defects
– Weld Spatter, remove them
– Sharp Edges, chamfer with grinder
NACE RMS 2013
• Unacceptable weld & edge defects
– Arc Strikes, remove them
NACE RMS 2013
• Unacceptable weld defects
– Slag Pockets
– Weld Spatter
– Cold Laps
– Stops/Starts not ground
NACE RMS 2013
• Poor Weld Profile
– Weld Spatter
– Sharp Edge
– Undercut
– Excessive Weld Sag
NACE RMS 2013
• SAW (Submerged Arc Welding) – No weld spatter, typically performed in shops
• GTAW (Gas Tungsten Arc Welding) – No weld spatter, typically performed in shops
• FCAW (Flux-Core Arc Welding) – Weld spatter but smooth weld profile
• GMAW (Gas Metal Arc Welding) – Lots of weld spatter
• SMAW – Lots of weld spatter & typically a rough profile, normally used for field welding – E6010 electrode very
rough weld profile
– E7018 electrode smoother profile then E6010
NACE RMS 2013
• SAW Weld • FCAW Weld
NACE RMS 2013
• SMAW E6010 Weld Profile
• SMAW E7018 Weld Profile
NACE RMS 2013
• Strip Coat/Seal the Welds and Beam Edges
NACE RMS 2013
• Holiday Testing
– Wet Sponge Testing
– Low/High Voltage Testing
– Used to Find Voids, cracks, thin spots, or even contaminates in the coating
NACE RMS 2013
• Weld Spatter & Rough welds that failed Holiday Testing
NACE RMS 2013
• Missed Holidays
– Use proper Testing procedure • NACE SP0188
• NACE SP0274
– Select proper testing equipment • Wet sponge good up to 20mils DFT
• Low/High Voltage set correctly based on average DFT of applied coatings
Missed Holidays
Missed Holidays
NACE RMS 2013
Thank you for attending
Questions ?