Guideline of Quality Assurance for Steel Structural Fabrication
Posted: 2015-8-26
By:
Ferdous Kabir
Source:
Self Experience
Guideline of Quality Assurance for Steel Structural Fabrication/
Process of Steel Structural Quality Assurance/
Steel Fabrication and Quality Assurance/
Importance of Third Party Inspection for Steel Structural Quality Assurance under Welding Code AWS D1.1/
During steel structure fabrication a lot of issues are depended on the quality of fabrication. The lifetime of steel building can be varied depending on quality of fabrication. That’s why, NDT inspections are most important during fabrication to ensure the quality of fabrication and ensure the safety and get the maximize life time of steel building structure for the end user.
If you are an owner, buyer, client or responsible representative of structure owner,
How you can assure the quality of fabrication?
The Third party inspection is the best way for assurance the quality by checking steel structure under the welding code AWS D1.1
All inspection activities are needed to carry out by certified engineers as ASNT, PCN, ISO NDT Level- II, AWS-CWI or CSWIP 3.1 under the guidance of ASNT Level-III & AWS-SCWI personnel. The coating activities are monitored, measured and controlled by experienced inspectors certified as BGAS-CSWIP and NACE.
What is the responsibility of the third party inspection of quality assurance for steel structure fabrication?
Responsibility of the third party inspector:-
01. To Check and confirm the welder performance that certified welder will perform or conduct welding at your project.
02. To Check the Welding machine performance and electrode quality.
03. To Check Factory Test Certificate and arrange to cross check of Material which will be using your project.
04. Visual Inspection
05. Dimension Check as per drawing
06. Dye Penetrant Test or Magnetic Particle Testing
07. Ultrasonic or Radiography Testing
08. Coating Thickness and Roughness Inspection
01. Welder Performance Check:
Welding Procedure Specification- which will provide the direction of welder or welding operators for making sound and quality production welds as per the drawing and code requirements.
Welder Performance Qualification Test Record-Before starting the welding at your project, You should appointed a AWS Certified inspector for select the good welder via different type of welding examination test process.
02. Material Quality Check:
At First you need to check material which steel will be use in your project. To get test certificate like material composition, grade, tensile and compression and different type of lab test certificate. Initially you need to cross check from local lab.
03. Welding Visual Inspection
An AWS visual inspector can ensure the welding preparation and quality before, during and after welding as per AWS D1.1guidline.
Inspection Zone: 100% of All Weld.
Findings:
Surface Crack, Blowhole, Undercut, Welding mismatch, Burn Through, Corner Melt, End Melt, Concave/Convex of Fillet Weld, Incomplete Fusion , Incomplete Penetration, Roughness, Undersize Filler Weld, Proper Welding Method, Under fill, Offset, Arc Strikes, Fabrication Scars, Spatter etc.
04. Dimension Check:
Dimension check by an engineer to ensure the correct measurement of steel member, anchor bolt hole, stiffener, clids etc according to the drawing.
Inspection Zone: All Steel Structure Members.
Findings:
1. Steel Member Length
2. Steel Plate Thickness
3. Anchor Bolt Hole Diameter
4. Anchor Bolt Hole to hole centre distance
5. Clid Measurement
6. Stiffener Measurement
05. Dye Penetrant Test:
Dye Penetrant Testing with Magnaflux DPT Chemicals by an ASNT DPT Level-II engineer and Imagery Report Interpretation.
Inspection Zone: 15% or more of All Fillet Weld.
Findings:
1. Very small surface Crack
2. Small Blowhole
3. Undercut
06. Ultrasonic Test:
Ultrasonic Testing with Advanced Ultrasonic Phased Array Flaw Detector is performed by an ASNT UT Level-II Engineer and S-Scan Imagery report Interpretation.
Inspection Zone: 100% of All Butt Weld
Findings:
1. Internal Defect of Butt Joint
2. Butt Joint Internal Crack
3. Butt Joint Internal Porosity
Most of the times, Steel structure fabrication companies try to avoid inspection because they have to chance material wastage when more correction will come around and when a welder may welding precisely so they need more concentration and more time, As a result , it affects the production speed .
07. Coating Thickness and Roughness Inspection:
Proper grade of coating, thickness and how many layer need to confirm your structural longevity.
To establish the effect of environmental corositivity, the following factor must be taken into account:
- Humidity and temperature (service temperature the temperature gradients)
- Chemical Exposure ( e.g specific exposure in industrial plant)
- The percentage of UV radiation
- Mechanical damage (impact, abrasion etc)
ISO 12944 standard gives the corrosion classification for atmospheric condition, soil and water.
An inspector will take care about the following points for minimize corrosive aggressiveness
- The type of paint used for protection
- The total thickness of a paint system
- The surface preparation
- Minimum and maximum recoating intervals.
If you are not concern about your structure, fabricator Company can compromise following points:
01. Mismatch the grade of material
02. Mismatch measurement of Material
03. They can avoid selected electrode for minimize the production cost.
04. They can involve unqualified welder and welding production quality will be poor, after painting client cannot understand the welding quality.
05. To rapid production, fabricator can avoid lot of defect and discontinue.
06. Dimension can be mismatch, fabricator company will correction it at the installation time alternative way and it will be affected in final structural quality.
07. Proper grade of coating, thickness and how many layers, you need to confirm your structural longevity.
If a steel budding owner desire a safe and good quality building, he should be keep a budget for inspection and appoint an expert group who are deal steel structural quality assurance issue.
Prepared By:
Ferdous Kabir
Marketing Manager
(ASNT NDT Level-II UT, RT, PT and ISO Level-II MT)
Saj Engineering & Trading Company
House# 351(5th Floor), Road# 05,
DOHS, Mirpur
Dhaka-1216
Bangladesh
Cell# +88-01817094194
Email: ferdous@sajetc.com
http://www.sajetc.com
Process of Steel Structural Quality Assurance/
Steel Fabrication and Quality Assurance/
Importance of Third Party Inspection for Steel Structural Quality Assurance under Welding Code AWS D1.1/
During steel structure fabrication a lot of issues are depended on the quality of fabrication. The lifetime of steel building can be varied depending on quality of fabrication. That’s why, NDT inspections are most important during fabrication to ensure the quality of fabrication and ensure the safety and get the maximize life time of steel building structure for the end user.
If you are an owner, buyer, client or responsible representative of structure owner,
How you can assure the quality of fabrication?
The Third party inspection is the best way for assurance the quality by checking steel structure under the welding code AWS D1.1
All inspection activities are needed to carry out by certified engineers as ASNT, PCN, ISO NDT Level- II, AWS-CWI or CSWIP 3.1 under the guidance of ASNT Level-III & AWS-SCWI personnel. The coating activities are monitored, measured and controlled by experienced inspectors certified as BGAS-CSWIP and NACE.
What is the responsibility of the third party inspection of quality assurance for steel structure fabrication?
Responsibility of the third party inspector:-
01. To Check and confirm the welder performance that certified welder will perform or conduct welding at your project.
02. To Check the Welding machine performance and electrode quality.
03. To Check Factory Test Certificate and arrange to cross check of Material which will be using your project.
04. Visual Inspection
05. Dimension Check as per drawing
06. Dye Penetrant Test or Magnetic Particle Testing
07. Ultrasonic or Radiography Testing
08. Coating Thickness and Roughness Inspection
01. Welder Performance Check:
Welding Procedure Specification- which will provide the direction of welder or welding operators for making sound and quality production welds as per the drawing and code requirements.
Welder Performance Qualification Test Record-Before starting the welding at your project, You should appointed a AWS Certified inspector for select the good welder via different type of welding examination test process.
02. Material Quality Check:
At First you need to check material which steel will be use in your project. To get test certificate like material composition, grade, tensile and compression and different type of lab test certificate. Initially you need to cross check from local lab.
03. Welding Visual Inspection
An AWS visual inspector can ensure the welding preparation and quality before, during and after welding as per AWS D1.1guidline.
Inspection Zone: 100% of All Weld.
Findings:
Surface Crack, Blowhole, Undercut, Welding mismatch, Burn Through, Corner Melt, End Melt, Concave/Convex of Fillet Weld, Incomplete Fusion , Incomplete Penetration, Roughness, Undersize Filler Weld, Proper Welding Method, Under fill, Offset, Arc Strikes, Fabrication Scars, Spatter etc.
04. Dimension Check:
Dimension check by an engineer to ensure the correct measurement of steel member, anchor bolt hole, stiffener, clids etc according to the drawing.
Inspection Zone: All Steel Structure Members.
Findings:
1. Steel Member Length
2. Steel Plate Thickness
3. Anchor Bolt Hole Diameter
4. Anchor Bolt Hole to hole centre distance
5. Clid Measurement
6. Stiffener Measurement
05. Dye Penetrant Test:
Dye Penetrant Testing with Magnaflux DPT Chemicals by an ASNT DPT Level-II engineer and Imagery Report Interpretation.
Inspection Zone: 15% or more of All Fillet Weld.
Findings:
1. Very small surface Crack
2. Small Blowhole
3. Undercut
06. Ultrasonic Test:
Ultrasonic Testing with Advanced Ultrasonic Phased Array Flaw Detector is performed by an ASNT UT Level-II Engineer and S-Scan Imagery report Interpretation.
Inspection Zone: 100% of All Butt Weld
Findings:
1. Internal Defect of Butt Joint
2. Butt Joint Internal Crack
3. Butt Joint Internal Porosity
Most of the times, Steel structure fabrication companies try to avoid inspection because they have to chance material wastage when more correction will come around and when a welder may welding precisely so they need more concentration and more time, As a result , it affects the production speed .
07. Coating Thickness and Roughness Inspection:
Proper grade of coating, thickness and how many layer need to confirm your structural longevity.
To establish the effect of environmental corositivity, the following factor must be taken into account:
- Humidity and temperature (service temperature the temperature gradients)
- Chemical Exposure ( e.g specific exposure in industrial plant)
- The percentage of UV radiation
- Mechanical damage (impact, abrasion etc)
ISO 12944 standard gives the corrosion classification for atmospheric condition, soil and water.
An inspector will take care about the following points for minimize corrosive aggressiveness
- The type of paint used for protection
- The total thickness of a paint system
- The surface preparation
- Minimum and maximum recoating intervals.
If you are not concern about your structure, fabricator Company can compromise following points:
01. Mismatch the grade of material
02. Mismatch measurement of Material
03. They can avoid selected electrode for minimize the production cost.
04. They can involve unqualified welder and welding production quality will be poor, after painting client cannot understand the welding quality.
05. To rapid production, fabricator can avoid lot of defect and discontinue.
06. Dimension can be mismatch, fabricator company will correction it at the installation time alternative way and it will be affected in final structural quality.
07. Proper grade of coating, thickness and how many layers, you need to confirm your structural longevity.
If a steel budding owner desire a safe and good quality building, he should be keep a budget for inspection and appoint an expert group who are deal steel structural quality assurance issue.
Prepared By:
Ferdous Kabir
Marketing Manager
(ASNT NDT Level-II UT, RT, PT and ISO Level-II MT)
Saj Engineering & Trading Company
House# 351(5th Floor), Road# 05,
DOHS, Mirpur
Dhaka-1216
Bangladesh
Cell# +88-01817094194
Email: ferdous@sajetc.com
http://www.sajetc.com
