The basic requirement of welding management is having a qualified welding procedure and qualified welders to AS1554 or AS3992.
When starting a project, it is important to understand what the project requires, or you may get caught out. As a minimum, the purchase order will specify AS1554 or AS4041 for example. On face value, companies do not always realise what this means. It can be difficult to navigate them and there is a lot of details to understand. The scope of work or purchase might be less discrete and specifically ask for certain quality documentation.
Some of the acronyms you need to keep in mind are;
- WQT or WPQ
If you’re unfamiliar with welding, those jumbles of letters probably look like a confusing bowl of alphabet soup. Here’s the translation.
- WPS – Welding Procedure Specifications
- PQR – Procedure Qualification Records, and
- WQT / WPQ – Welder Qualification Test / Welder Performance Qualifications.
These all have a different purpose. This blog attempts to demystify welding documentation.
Preliminary (proposed) Welding Procedure Specifications (WPS)
pWPS is essentially a guide for the person that is going to weld the PQR test coupon and it can also be used as a document to get in principal approval from the client. You give the client the change to review what you intend to do, ie. if I run the test like this and do this testing, will you be happy with it.
This is not always required, but it is specified in some standards. It can save heartache buy ensuring the client is happy with the WPS at the end.
Welding Procedure Specifications (WPS)
WPS is essentially a welder’s guide that includes applicable code requirements and production standards. It controls the welding process.
It has been compared to a recipe for welders. When cooking a roast, the recipe includes all the ingredients you need, plus the actual steps you will need to make sure the roast works out right and is repeatable.
A WPS is very similar. It includes details on what you will need and the welding processes to follow that will create a sound weld. However, instead of listing type of meat, barbeque temperature, time you should for, a WPS lists information such as base metal grade, amps, volts and travel speed along with many other details.
The WPS is a proven process of welding and is important to ensure welding operators in the field are maintaining the same, required standards across the board. The mechanical properties of a weld cannot be verified in production welds after welding so control of the welding process using a WPS is critical.
If either a novice or experienced welder follow the WPS, they should be able to produce welds with similar mechanical properties. This helps new welders grow to the same level as experienced welders. It ensures clients are receiving serviceable welds that are the strength, toughness and soundness required by the design.
A WPS always has ranges to allow for joint and operator technique variation, it is unlikely every joint is the same or every welder uses the same technique. These ranges are different for every standard. The ranges are based on what is known as essential variables. Things which if changed require you to requalify the WPS.
Procedure Qualification Records (PQR)
All WPSs start with a PQR. It is a record of the test. It DOES NOT have any ranges. It lists the actual values recorded during the welding of a test piece. It proves the welding process.
Then using the essential variables (ranges) from the relevant code/standard a WPS can be generated from this record of actual values.
PQR is essentially the ‘actual’ method that is used to create and test the welds to ensure they meet all applicable requirements.
The test procedures and final results are documented in the PQR. If the PQR meets the set standards of the welding world, then it will serve as the foundation on which one or more WPSs are drafted.
Even though a PQR eventually leads to a WPS, it is important for welders to have knowledge of both documents. In critical applications and in mechanised and automatic welds welders can refer to the PQR and replicate the actual values used in the test weld, this removes all the variation.
On face value, these documents look very similar but serve completely different purposes.
The best way to think of it is;
- PQR is an office document
- WPS is a workshop document
Both are necessary in most cases. The PQR supports the WPS as evidence of qualification.
Welder Qualification Test / Welder Performance Qualifications (WQT/WPQ)
While WPS and PQR are used to define and prove the welding process.
WQT/WPQ is used to test the actual welder. Is the welder able to produce a sound weld;
- 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.
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).
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;
- Bend tests – root/face or sides
- Macro test – cross section view of weld
- Fillet weld break test
- Nick Break
- Radiographic examination
- Ultrasonic examination
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
Some of these standards like AS/NZS 2980 and ISO 9606 have an optional knowledge which can be used to help understand the level of your welders knowledge. Being able to weld and understanding welding are two different things. Someone that has a proven ability to understand what affects the outcome will always be a better option.
If you are looking to hire a welder, you can ask about previous WQT before hiring them. Generally companies pay for the WQT so it remains the companies property not the welders, So welders will not always have them. Certain standards do not allow the transfer of the qualifications. If you are looking for some assistance there are a number of providers that can assist with WQT online that will help you develop your welding management system.
It should be noted that qualification and certification are different things, the differences between the two will be explained in a different blog.
If the welding world confuses you, hopefully this has gone some way to demystifying it.
The terms may seem overwhelming, but the documents these acronyms represent are extremely important to the welding industry.
Some More Common Industry Acronyms
Below we’ve tabled some more common welding industry acronyms and their meanings:
|AS||Australian Standards including joint Australian and New Zealand standards|
|AWI||Australian Welding Institute|
|ISO||International Standards Organisation|
|AWS||American Welding Society|
|CQS||Certified Quality System|
|CSWIP||Certification Scheme for Inspection Personnel|
|ITP||Inspection and test plan(s).|
|MDR||Manufacturers Data Report|
|NDT/NDE||Non Destructive Testing / Examination|
|TWI||The Welding Institute – UK|
|UNO||Unless noted otherwise|
Our team at Technoweld are highly experienced in all things welding and we’re standing by to help you navigate your way through the acronym soup that guides professional welders the world over. Contact us directly on 1300 00 WELD and chat with us today about how we can help your company upskill staff, increase your overall output quality and win at welding.