Welding Performance Qualification Test (WPQT)
WELDER QUALIFICATION TEST (WQT) /
WELDER PERFORMANCE QUALIFICATIONS TEST (WPQT)
While WPS and PQR are used to define and prove the welding process.
WQT/WPQT is used to test the actual welder.
Is the welder able to produce a sound weld, with the following
• With a particular welding process ie. GMAW or GTAW
• In a given position Horizontal, Vertical or Overhead
• On a particular joint configuration Butt weld or Fillet weld.
A WQT does not test the mechanical properties, it looks at weld soundness only in most cases.
WELDER QUALIFICATION TEST (WQT) /
WELDER PERFORMANCE QUALIFICATIONS TEST (WPQT)
A Welder Qualification Test is recorded on documentation known as a test certificate that details the ranges that welder is qualified.
Ranges or essential variables for WQT are not always the same as those for a WPS.
An example would be that is a welder can weld in the overhead position (more difficult) it is logical they be qualified in the flat position (less difficult).
Welder Qualification Essential variable
Joints
– With or without backing
Base metal
– Pipe diameter
– P number
Welder Qualification Essential variable
• Filler Metal
• With or without
• F-number
• Inserts
• Solid or metal cored
• “t” of deposit
• “t” limits of short-circuiting transfer
- Position
– Flat
– Horizontal
– Vertical
– Overhead
Progression – Vertical Welding
– Up
– Down
Welder Qualification Essential Variable
Gas
– Deletion of inert backing gas
Electrical characteristics
– GMAW – transfer mode
– GTAW – current or polarity
Welder Qualification
Main controlling factors
• Process
• Filler metal
• P number qualified
» It is your responsibility to ensure that the filler metal and base metal are suitable for the application
Welder Qualification Base Metal
Test on pipe or plate?
Any P-No. 1 through 11, P-No. 34, or P- No. 41 through 47 qualifies for any No. 1 through 11, P-No. through 47 base metal
P-No. 21 through P-No. 25 (same)
P-No. 51 through P-No. 53 or P-No. 61
through P-No. 62
Welder Qualification
F - Numbers
Some cross qualification exists with
F numbers for example
• Any F6 qualifies for F6
• Any F21 – F25 qualifies for F21 – F25
• Any F34 or F41 – F47 qualifies for F34 & F41 - F47
Welder Qualification
F-Numbers
SMAW electrode F numbers 1 – 4 are inter-related (ASME) and with or
without backing applies
– F4 without backing qualifies for F1, F2, F3 & F4 with backing and F4 without
– F4 with backing qualifies for F1, F2, F3 & F4 with backing only
Welder Qualification Weld Deposit “t”
ASME
• Up to and including 3/8” thick qualifies 2t
• Over 3/8” qualifies 2t
• 1/2” & over with minimum of 3 layers of weld metal qualifies for the maximum to be welded
AWS D1.1
• 1/8” to 3/8” qualifies for 2t
• 3/8” < t < 1” qualifies for 2t
• 1” and over qualifies for unlimited
Welder Qualification
Position (ASME)
1G plate qualifies
– F plate & pipe 2 7/8” OD & over groove welds and F fillets
2G plate qualifies
– F & H plate & pipe 2 7/8 “ & over groove welds and F & H fillets
Welder Qualification
Position (ASME)
3G plate qualifies
– F & V plate & pipe groove welds 24” OD & over and F, H, V fillets
– F pipe 2 7/8” OD & over groove welds
4G plate qualifies
– F & O plate & pipe groove welds 24” OD & over and F, H, O fillets
– F pipe 2 7/8” OD & over groove welds
Welder Qualification
Position (ASME)
1G pipe
– F groove & fillet
2G pipe
– F & H groove & fillet
5G pipe
– F, V & O groove & fillet
2G & 5G pipe or 6G pipe
– All groove & fillet
Welder Qualification
Position (ASME)
Diameter limits based on OD of test coupon for groove welds
• < 1” OD = size welded to unlimited
• 1 < 2 7/8” OD = 1” OD to unlimited
• 2 7/8” OD & over = 2 7/8” OD to unlimited
Groove weld test qualifies fillets for all base material thickness, sizes and diameters
Welder Qualification
Most testing can be done on carbon steel test coupons to save money
- e.g., welder qualifications can be completed for most nickel alloys by using a filler from the F-41 through F-47 group welding a carbon steel test coupon
6G pipe position is the most economical test position
Qualification by Workmanship Test
• Only permitted when allowed by the referencing document
• Requires completion of a workmanship test addressing typical production joints and conditions
• Primarily accepted on the basis of visual inspection
• Other tests or examinations may be required by the referencing document (e.g., macro examination)
What’s the difference between a qualified welder and certified welder?
The definition and some details from ASME Boiler and Pressure Vessel Code Section IX is discussed below:
Qualified Welder – One who has the skills necessary to produce sound welds with a given process, position, material, etc.
Certified Welder – One who is qualified and the qualification is documented and signed by the company the welder works for.
Performance Qualification Test and
Performance Qualification Record
For example, ASME Section IX, QW-300 through QW-380 covers the requirements for Welding Performance Qualification.
This includes instruction for qualification tests, destructive/non-destructive examination requirements, and the essential and non-essential variables.
In addition to the performance qualification test, the organizations performing the tests are required to complete a Performance Qualification Record.
Completing the Performance Qualification Record is the company’s method of certified welders.
ASME Section IX states the following in the General Requirements Section QG-104, “The organization shall certify a performance qualification record by signature”. With the quick whip of a pen, the welder goes from qualified to qualified and certified!
Performance Qualification Test
The type and number of tests required are detailed in the relevant standard. The most common standards are for WQT are;
• AS/NZS 1554
• AS/NZS 2980
• AS NZS ISO 9606
• AS/NZS 3992
• AWS D1.1
• ASME IX
Performance Qualification Test
The welder completes a test coupon under supervision following a WPS. The weld is then tested using the method prescribed in the relevant standard.
The testing always includes as a minimum visual examination but may also require;
1. Bend tests – root/face or sides
2. Macro test – cross-section view of the weld
3. Fillet weld break test
4. Nick Break
5. Radiographic examination
6. Ultrasonic examination