WPS example for EN 1090: a completed welding procedure specification

A WPS (welding procedure specification) is the written work instruction for one welding method, for one combination of material, thickness and joint. Under EN 1090, every WPS in use belongs to a qualified welding method, recorded in a WPQR (welding procedure qualification record). The requirements for welding methods come from ISO 3834, and the WPS belongs in your FPC system. Below is a completed example that you can use as a template, with the fields an auditor most wants to see.

Short answer: a WPS is the instruction for the welder, and a WPQR is the proof that the instruction works. Without a WPQR behind it, the WPS is an unsupported work instruction.

The execution class you work to determines how strict the qualification is. See the page on execution classes. The technical basis for qualifying welding methods for steel is EN ISO 15614-1. For aluminium, EN ISO 15614-2 applies, see the page on EN 1090-3 aluminium. These are different standards from EN 1090 itself. So check the precise requirements in the standard and with your certifying body.

What is the difference between a WPS and a WPQR?

People often confuse the two. The difference is simple:

Document	What it is	Who makes it	Who uses it
pWPS (preliminary WPS)	The draft procedure before the test	Welding coordinator or welding technologist	Basis for the test weld
WPQR (qualification record)	Report of the test weld with the test results	The laboratory or test body	Proof that the procedure complies
WPS (final procedure)	The work instruction on the shop floor	Welding coordinator, based on the WPQR	Welder and inspection

You may only use a WPS within the range of the WPQR that supports it. Outside that range, for example a thicker plate or a different gas mixture, you need a new test weld or a different WPQR.

Example: completed WPS for a column-to-beam joint

The example below is fictional. The values are illustrative and not meant as a basis for production. You take the values over from your own WPQR.

Field	Completed value
WPS number	WPS-01 rev. 2
Standard	EN 1090-2, ISO 15614-1 (WPQR-2023-01)
Welding process	135 (MAG, solid wire)
Base material	S355J2, group 1.2
Thickness	8 to 20 mm (range from the WPQR)
Joint	Fillet weld, T-joint, single side
Welding positions	PA, PB (ISO 6947)
Filler metal	Solid wire G4Si1, diameter 1.2 mm
Shielding gas	M21, 82% argon and 18% CO2
Gas flow	15 to 18 l/min
Preheating	Not required for thicknesses above 8 mm and ambient temperature above 5 °C (fictional)
Interpass temperature	Maximum 250 °C (fictional)
Current and voltage	Within the range of the WPQR, see appendix
Post-weld treatment	Slag removal and visual inspection
Weld testing	Visual, and sampling with dye penetrant or magnetic particle testing
Status	Current, linked to WPQR-2023-01

Take the values for current, voltage and preheating from the WPQR. Enter them in the WPS as a range, not as a single figure, so the welder stays within the qualification.

What a good WPS must contain at minimum

A WPS does not need to be long, but its fields must be complete. Use this checklist when you draft one:

Record the process and the standard

Note the welding process with its ISO 4063 number, such as 135 for MAG with solid wire. State the standard on which the WPS is based.

Describe the material and the joint

Note the steel grade, thickness, joint type and welding positions. The steel grade and thickness determine which WPQR you need.

Record the setting parameters as a range

Give the current, voltage, wire feed speed, gas flow and heat input as a range. The range comes from the WPQR and is never wider.

Link the WPQR and have the WPS approved

Refer to the WPQR number. Have the welding coordinator sign and date the WPS, and record the revision.

What does the auditor want to see for WPSs?

The auditor usually picks one WPS and asks for the supporting evidence. They look at three things.

A WPQR that covers the WPS, with the same steel grade, thickness and welding process within the range.
A welder who is qualified for that WPS. The welder certificate appears on the welder matrix, with its validity date.
Proof that the WPS is used in the workshop, for example on the work order or in the inspection report.

If you cannot link the WPS to a WPQR, the auditor records it as a deviation. This is one of the most common findings for welding.

A WPS that you copied from a supplier, without your own WPQR, is not a qualification. Even if the supplier has a certificate, you must be able to show that the procedure works in your own workshop.

Common mistakes with a WPS

The WPS is older than the WPQR. After a revision, the WPS must refer to the WPQR that now covers it. Archive old revisions rather than deleting them.

Going outside the range. A WPS that names 25 mm plate while the WPQR goes up to 20 mm is not covered. This is the most common mistake.

No link to the work order. If the work order does not refer to the WPS, nobody can later see which procedure was used. That is also a problem for traceability.

Welder not qualified for the WPS. A WPS may exist, but the welder must be qualified for that procedure and position.

Frequently asked questions about the WPS

Do I need a WPS for every weld?

You need a WPS for every welding method you use and every combination of material and joint in your workshop. Many companies work with a limited number of WPSs that together cover their whole range of production.

Can one WPQR support several WPSs?

Yes, as long as the WPSs fall within the range of the WPQR. You record that range in the standard and in the WPQR itself. If you go outside it, you need a new test weld.

Where do I find the requirements for the WPS in the standard?

The requirements are in EN 1090-2 and in EN ISO 15614-1 for the qualification of steel. You check the exact clauses and tables in the standard itself. This page explains the structure. It does not replace the text of the standard.