Cost-effective and fast: let Lorch help you become EN 1090-certified!

What execution classes are there?

The EN 1090 defines four different execution classes, each mandating its own specific set of requirements that need to be satisfied by the welding personnel.

  1. Execution class EXC1
    This class includes steel components or structures up to strength class S275 that are subjected to predominantly static loads, for instance:

    • Support structures with up to two floors consisting of rolled-steel
    • Support structures composed of stress planes with an incline of no more than 30° (e.g. ramps)
    • Staircases and railings in residential buildings
    • Conservatories on residential properties
    • Single-family houses with up to 4 floors

  2. Execution class EXC2
    Subsumed under this category are steel components and structures up to strength class S700 that are subjected to predominantly static and predominantly non-static loads and cannot be assigned to execution classes EXC1, EXC3 and EXC4.

  3. Execution class EXC3
    This class comprises steel components and structures up to strength class S700 that are subjected to predominantly static and predominantly non-static loads including:

    • Large-area roof structures overhanging places of public assembly / stadiums
    • Buildings with more than 15 floors
    • Pedestrian and bicycle bridges
    • Roadway bridges
    • Railway bridges
    • Fairground rides
    • Towers and masts including antenna support structures
    • Crane tracks
    • Cylindrical towers such as steel smoke stacks

  4. Execution class EXC4
    This category comprises all components or structures listed under execution class EXC 3 that involve extreme consequences for people and/or the environment in the event of failure. Examples include:

    • Railroad and roadway bridges (see DIN EN 1991-1-7) over densely populated residential areas or industrial plants with hazardous potential
    • Safety tanks in nuclear power plants

Requirements to be met by welding operations

The execution of jobs subject to building authority approval and the participation in tendering procedures require proof sufficient to confirm the professional qualification of personnel and must include qualified welding processes and documents detailing the use of the required technical equipment.

Businesses will be audited by an external inspector or an accredited test body such as GSI-SLV, TÜV or DEKRA. In addition to individual tests, the EN 1090 also sanctions standard welding processes as eligible for certification.

One key prerequisite that needs to be satisfied to obtain this certification is a factory production control system (FPC). The FPC must incorporate all processes that are essential for the production of steel and aluminium structures - from dimensioning to purchasing to corrosion protection to assembly.

All efforts to assure quality must be merged into a continuous and dedicated production monitoring system maintained by the manufacturer.

5 steps to your success

  1. Preliminary planning
    Reproduction of a theoretical operating process sequence from purchasing to shipping. The objective is to demonstrate that your company assures quality along the entire chain of value creation. Appropriate aids and tools such as checklists or manuals are available in the marketplace.

  2. Employee training
    Depending on the kind of component you manufacture and the execution class applicable to this component, you may also be required to provide proof of the qualification and training given to individual members of your staff and the welding coordinator. This mandate may require that you provide additional training courses.

  3. Factory production control (FPC)
    To stay in compliance with the stipulated requirements, you must certify in writing that all work steps during production have been completed as required - in a form that allows for clear determination of compliance at all times. This applies, in particular, to welding operations as you are required to provide a written WPS (Welding Procedure Specification) for each and every weld seam grouped under execution class EXC2 or higher.

  4. Qualification of welding processes
    Within the EN 1090 all your welding processes (EXC 2 and higher) have to get qualified. Depending on the EXC this qualification can happen on the basis of various norms. The following table provides an overview:

5. Preparing welding procedure specifications
    You have satisfied all requirements the law stipulates for the audit and certification    
    according to EN 1090.

The solution: Lorch's WPS package

Separately available for each line of machines, the WPS package contains all welding procedure specifications necessary for regular applications – certified by the Teaching and Research Institute for Welding Technology (GSI-SLV) Fellbach – and are suitable for use at your own welding company.

Covering MIG-MAG Standard, MIG-MAG Pulse, the productivity-boosting SpeedPulse process as well as SpeedUp for quick and easy vertical seams, the specifications will pertain to the lion's share of standard procedures that need to be carried out at your company.

All certified standard welding processes including all relevant welding procedure specifications apply to the Lorch series P-Synergic, S, S-SpeedPulse & MicorMIG.

Important: Any approval of standard welding processes under EN 1090 always applies only to processes grouped under execution class EXC2 and only to materials up to and including strength class S355. All higher-level execution classes and strength classes require approval in accordance with DIN EN ISO 15613 or 15614-1!

Equally important: Do not use your Lorch equipment in combination with welding procedure specifications other than those included in the WPS packages we supply. Since every welding procedure qualification test is specific to the machine under testing, you will have to, at minimum, prove electrical and mechanical comparability to the auditor if you use welding procedure specifications with your Lorch machine that are supplied by third parties.

All owners of a WPS package are given online access to the entire WPQR test library documenting the welding process specifications contained in the corresponding WPS booklet. This also allows auditors to review the test results to the extent necessary for the completion of the audit.  Demo login information is available and can be used to catch a glimpse of the portal and access a sample WPS.

The perfect companion: Lorch Q-Data

Depending on the EXC, DIN EN 1090 requires the suitable implementation of DIN EN 3834, which says that essential parameters, such as welding current and welding voltage have to be monitored. Lorch Q-Data is a system that makes it a breeze to stay in compliance with the principal requirement of the EN 1090 - the documentation of the weld seams. One recorder per welding unit with a storage capacity that allows you to weld for at least a whole month. The package comes with software that clearly shows all of your welding activity. Better still, the system offers comprehensive connectivity as you can transfer data via USB, by Ethernet or wirelessly over your company's Wi-Fi network.

The use of this system will give you the transparency you need to analyse the welding results produced by your staff and to verify that they are in line with your company's specifications.

The Lorch Calibration System

Moreover, DIN EN 1090-1 demands to calibrate measuring and test equipment, which has impact on the conformity of the construction parts. Have a look at our smart solution.


Lorch Schweißtechnik GmbH
Im Anwänder 24 – 26
71549 Auenwald


T +49 7191 503-0
F +49 7191 503-199

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