In the field of welding, the abbreviations WPS and WPQR form the base of every weld. They describe technical procedures that comply with the very strict standards and regulations of welding. These procedures are the reason why it is possible to infinitely repeat welds with a consistent, high level of quality.
Let’s first recall the differences between the tasks of a welding machine operator and a trained welder.
Welder or welding machine operator – a significant difference
- Welder Performance Qualification (WPQ): a welder is qualified to perform a welding process, to operate a welding position, an assembly as well as to work with different types of metal
- Welding Operator Performance Qualification (WOPQ): the field of action of a welding operator on the other hand is limited to the machine he is certified on
2 types of machines – 2 types of qualification
Let’s try to make the distinction between automated and mechanized welding. Automated welding stations are operated – just like welding robots – by simply pressing a Start and Stop button. As soon as human intervention is required to receive a welding result, we speak of mechanized welding.
The welding operator qualified in automated welding will be certified on one type of machine and welding head, whereas in mechanized welding this person will be certified for a global process, for example mechanized orbital TIG welding.
Continuous training for operators and welders
The initial training that a welder pursues does not qualify him for life. A certificate of qualification is valid for 2 years. Every 6 months, the certificate needs to be renewed by the employer. The welder cannot interrupt his work for longer than 6 months at a time – and he needs to provide proof of this. If he doesn’t, he will have to once again carry out a weld on an examination piece to get recertified.
Every 2 years, the Welder's Performance Qualification (WPQ) must be renewed under certain conditions by an official organization (standard: EN 287-1 and for welding operators in accordance with EN 1418).
WPQR: Welding Procedure Qualification Record
A weld needs to be validated by an external, certified organization before starting a production series with orbital welds.
The samples are welded with a procedure called WPQR under the surveillance of an inspector and then sent to a laboratory to be subjected to various tests (hardness and compression testing, macroscopy, tensile testing, bending, etc.). Once validated, the procedure is then transferred into a WPS.
WPS: Welding Procedure Specification
A WPS allows companies to repeat welds in series, which will present the same level of quality repeatedly, provided that the welds are carried out under the same conditions (environment, quality of the raw material, etc.). The WPS contains all the information necessary to prepare the welding: the setting of the power supply, the materials used (tubes, filler metal, etc.).
A reminder: For a welder to be qualified, he must know how to interpret a WPS and respect its instructions.
Everything there is to know about WPS
All the necessary information about WPS can be found in the standard NF EN ISO 15609 (NF EN 288-2).