The Welding Performance Qualification (WPQ) is a certification test that shows certain skills of welders to perform a certain welding procedure. In other words, WPQ is a performance test of welders that determine if they have the capability of laying quality welds using procedures, materials, and welding processes. Applicants after passing the test, are given qualification record i.e. Welder Performance Qualification Record (WPQR). Generally, the WPQ test consists of destructive and non-destructive tests.
- What is Welding Performance Qualification?
- Welding Performance Qualification (AWS Codes)
- WPQ Requirements in ASME Code Section IX
- ASME and AWS Welding Codes Differences
- Welder Performance Qualification Tests
What is Welding Performance Qualification?
Welding Performance Qualification (WPQ) or Welder Performance Qualification Record (WPQR) is a testing procedure of welders or welding operators for depositing sound weld metal. In simple words, it is a certificate of welder’s test which indicates his/her required experience and knowledge of doing a welding procedure. Therefore, the WPQ test is conducted strictly according to the applicable welding codes which are as follows:
Welding Performance Qualification (AWS Codes)
The main purpose of welding codes is to improve skills, materials, processes, and equipment. AWS Codes are important in achieving maximum efficiency and quality in welding activities.
- AWS D1.1 – Structural Welding Code – Steel
- AWS D1.2 – Structural Welding Code – Aluminum
- AWS D1.3 – Structural Welding Code – Sheet Steel
- AWS D1.5 – Bridge Welding Code
- AWS D1.6 – Structural Welding Code – Stainless Steel
- AWS D9.1 – Sheet Metal Welding Code (non-structural)
- AWS D17.1 – Specification for Fusion Welding of Aerospace Applications
ASME Section IX – Boiler and Pressure Vessel Code (Welding and Brazing)
Normally, the Welding Performance Qualification explains the essential variables like position, thickness, material, and pipe diameter, etc. The WPQ can be performed either by radiography testing or ultrasonic testing and by mechanical testing alternatively. Both the face bend test or root bend test can check the WPQ. The bend test method is the most important faction in determining the difficulty level of weld-metal.
WPQ Requirements in ASME Section IX
The following are some of the variables and parameters necessary for WPQ in ASME Code Section IX.
1. F-Number is listed in QW-432 in ASME Code Section IX table. The change from one F-number to another F-number in welding is crucial for the WPQ procedure.
2. Back welding is an important variable and during this, metal or ceramic plate is used as a back-up. The main function of it is to absorb maximum heat and avoid too much melting.
3. T Weld Deposit is also an essential variable in determining the WPQ procedure. Weld deposit defines that metal in a fusion process consisting of a melted portion of base metal and filler metal during welding.
4. Pipe Diameter rules are listed in the QW-452.3 table. Every welder can only perform specific welding in which he/she is qualified. For example, a welder qualified in a 2-inch pipe cannot weld a 6-inch pipe.
5. Welding Position is also an essential factor in WPS and listed in the QW-461.9 table. A welder possessing a 6G position can weld all positions. These positions are 1G, 2G, 3G, 4G, 5G, and 6G.
6. P Number is a crucial factor in WPQ. The QW- 423 table consists of the limitations for P numbers. P number is also considered in the construction code for Weld Heat Treatment degree and duration.
What is the P number in welding?
P numbers are groupings of base metals. They are approved for pressure boundaries while constructing pressure vessels or piping systems. The P numbers are further sub-divided into other P numbers. The number is an essential factor for determining toughness. P number is addressed in the QW-422 table.
Application of P number
P number is an essential factor in welding processes. It is an important variable in WPQ as well. P numbers are categorized in the following table:
|3||Up to 1/2% Cr
Up to 1/2% Mo
|4||Up to 1 to 2% Cr
Up to 1/2% Mo
|5A||Up to 2 to 3% Cr
Up to 1% Mo Alloy Steel
|5B||Up to 5 to 10% Cr
Up to 1% Mo Alloy Steel
|5C||All 5A and 5B Materials heat-treated to 85ksi+|
|6||Martensitic Stainless Steel|
|7||Ferritic Stainless Steel|
|8||Austenitic Stainless Steel|
|9||Up to 2 to 5% Ni Alloy Steel|
High Cr Alloy Steels
|11||Low Alloy Steel, Quenched and Tempered to 95ksi+|
|21||1.2% Mg or Mn alloy Aluminum|
0.25% Cu Aluminum
0.25% Cr Aluminum
0.25% Cr Aluminum
0.15% Cr Aluminum
The welding is not the only field where P numbers are used. They are also considered in construction codes for checking duration and degree of post-weld heat treatment (UCS-56). Besides this, P numbers are also used in Radiographic Testing.
ASME and AWS Welding Codes Differences
The most common codes for qualifying of welders are American Welding Society (AWS) D1.1 and American Society of Mechanical Engineers (ASME) Section IX. Normally, people consider the ASME codes more stringent than AWS codes. The main difference between AWS D1.1 and ASME Section IX is as follows:
|AWS Codes||ASME Codes|
|AWS D1.1 addresses inspection, fabrication, erection, and welder and welding procedure qualification.||ASME specifically explains the welder and welding procedure qualification.|
Welder Performance Qualification Tests
The performance qualification test for welders is performed as per their requirements and areas of interest in welding. Generally, there are five types of WPQ tests.
- Visual Inspection Test
- Bend Test (Side, Face, Root)
- Macro-Etch Test
- Fillet Weld Break Test
- Radiographic Test
Thus, the Welding Performance Qualification or WPQ is an essential qualification test for welders to perform certain welding procedures. Besides this, the welding codes contain the crucial and necessary information pertaining to accuracy and quality.
Related: Other Welding Certifications