Welder Qualification

The use of qualified WPSs is the accepted method for controlling production welding but this will only be successful if the welders are able to understand and work in accordance with them.

Welders also need to have the skill to consistently produce sound welds (free from defects).

Welding Standards have been developed to give guidance on what particular test welds are required in order to show that welders have the required skills to make particular types of production welds in particular materials.

Welding standards for welder qualification

The principal European Standards that specify requirements are:

EN 287-1 Qualification test of welders – Fusion welding

Part 1: Steels

EN ISO 9606-2 Qualification test of welders – Fusion welding

Part 2: Aluminium and aluminium alloys

EN 1418 Welding personnel – Approval testing of operators for fusion welding and resistance weld for fully mechanized and automatic welding materials

The principal American Standards that specify requirements qualification are:

ASME Section IX Pressurized systems (vessels & pipe work)

AWS D1.1 Structural welding of steels

AWS D1.2 Structural welding of aluminium

 The qualification process for welders

Qualification testing of welders to European Standards requires test welds to be made and subjected to specified tests to demonstrate that the welder is able to understand the WPS and to produce a sound weld.

For manual and semi-automatic welding the emphasis of the tests is to demonstrate the ability to manipulate the electrode or welding torch.

For mechanized and automatic welding the emphasis is on demonstrating that welding operators have the ability to control particular types of welding equipment.

American Standards allow welders to demonstrate that they can produce sound welds by subjecting their first production weld to NDT.

Welder qualification and production welding allowed

The welder is allowed to make production welds within the range qualification recorded on his Welder Qualification Certificate.

The range of qualification is based on the limits specified by the Welding Standard for welder qualification essential variables s – defined as:

A variable that if changed beyond the limits specified by the Welding Standard may require greater skill than has been demonstrated by test weld

Some welding variables that are classed as essential for welder qualification are the same types as those classified as essential for welding procedure qualification, but the range of qualification may be significantly wider.

Some essential variables are specific to welder qualification.

Period of validity for a welder qualification certificate

A welder’s qualification begins from the date of welding of the test piece.

The European Standard allows a qualification certificate to remain valid for a period of two years, provided that:

The welding coordinator, or other responsible person, can confirm that the welder has been working within the initial range of qualification.

Working within the initial qualification range is confirmed every six months.

Prolongation of welder qualification

A welder’s qualification certificate can be prolonged every two years by an examiner/examining body but before prolongation is allowed certain conditions need to be satisfied:

Records/evidence are available that can be traced to the welder and the WPSs used for production welding. Supporting evidence must relate to volumetric examination of the welder’s production welds (RT or UT) on two welds made during the six months prior to the prolongation date.

Supporting evidence welds must satisfy the acceptance levels for imperfections specified by the European welding standard and have been made under the same conditions as the original test weld.