Quality Management

Welding Quality Management System and Factory Production Control according to EN 1090-1/2:2009 +A1:2011,together with the ISO 3834-2 standard.
 
STE Staal bv is certified for Execution Class 3. What does this mean?
 
If the steel construction does not include
• non-load bearing building products such as fences, handrails
• Building products with own standards such as gates, doors, facades
• No building products for example machine construction
Only, the construction must be manufactured by an EN 1090-1 certificated steel workshop.
 
Depending on the demands, the level of certification has to be chosen.
 
For a better understanding, we here want to explain how to determine the necessary Execution Class and for which constructions these have to be executed.
 
Execution Class selection in 4 steps:
 
Step 1: Defining the consequence class CC
 
 
The consequence class ensures the appropriate level of quality control. The definition of the different consequence classes is based on building type, building height (number of levels), floor plan area per level (for retail) and occupancy. It is possible that a (part of a) structure contains components with different consequence classes. In most cases, CC2 will be suitable.
  
Step 2: Selecting a service category SC
 
 
The risk arising from the actions to which the structure and its parts are likely to be exposed during erection and use classifies the category criteria of Service categories. Risks can be for example fatigue, likelihood of seismic actions and stress levels in the components in relation to their resistance determine. 
 
The service category is determined according to Table B.1 of EN 1090-2. 
 
Step 3: Selecting a production category PC
 
 
A production category is determined by the risk arising from the fabrication complexity of the structure and its components. According to the method of fabrication the application of particular techniques, procedures and controls will be necessary.
 
The production category is determined according to Table B.2 of EN 1090-2.
 
It is possible that a structure or part of a structure can contain components or structural details that belong to different production categories.
 
Step 4: Determination of the execution class
 
 
The corresponding execution class can now be defined according to Table B.3 of EN 1090-2.
 
EXC2 will be applicable to most buildings. Further, clause 4.1.2 of EN 1090-2 states that EXC2 applies where no execution class is specified.
 
Execution Classes and  construction types
 
In practice, the Execution Classes have to be chosen for the following construction types.
 
Execution Class 1 (EXC1):
- Predominantly components at rest and
- Steel to strength class S275
for which at least one of the following items applies:
1. Supporting structures with
- Max. two levels made of rolled sections without rigid butt joint end plates.
- Supports with max. 3m buckling length.
- Bumper bracket with max. 5. span and cantilever up to 2m.
- Characteristic variable evenly distributed influences / payloads up to 2.5 kN /m2 and characteristic variable single payloads up to 2.0 kN,
2. Load carrying systems with max. 30 ° inclined allocation levels (for example ramps) with stress by characteristic axle loads of max. 63kN or characteristic variable, evenly distributed exposure/ payloads of up to 17.5 kN /m2 at a height of max. 1.25m above solid ground.
3. Stairs and railings in residential buildings
4. Agricultural buildings without regular passenger traffic
5. Winter gardens in residential buildings
6. Buildings that are rarely entered by persons with a distance to other buildings or areas with frequent use by persons of at least 1.5 times the height of the building.
And comparable civil works, structures and components.
 
Execution Class 2 (EXC2):
- Predominantly at rest and non-predominantly at rest stressed  components or loadbearing structures
- Steel up to production class S700
Everything that is not  referable to Exc1, Exc3, and Exc4
 
Execution Class 3 (EXC3):
- Predominantly at rest and non-predominantly at rest stressed components or loadbearing structures
- Steel up to production class S700
For which at least one of the following items applies:
1. Large-scale roof constructions of public assembly places/ stadia
2. Buildings with more than 15 floors
3. Predominantly at rest stressed weir gates with extreme outlet volumes
4. The following not predominantly at rest stressed loadbearing structures or their components:
- footpath- and bicycle path bridges
- road bridges
- railway bridges
- temporary buildings/ -structures
- towers and masts, e.g. radio mast
- crane runways
- cylindrical towers, e.g. steel chimneys
and comparable civil works, structures and components.
 
Execution Class 4 (EXC4):
All components or structures of EXC 3 with extreme consequences at failure for people and the environment, such as:
Footpaths bridges, bicycle path bridges, road bridges and railway bridges over densely populated areas or industrial plants with high risk potential
safety containers in nuclear power plants
Non-predominantly stressed weir gates with extreme outlet volumes.
 
What are the effects for an EN 1090 qualified steel workshop? 
 
Depending on the Execution Class, there are different demands on 
- steel workshop 
- welders qualifications
- welding techniques
- testing procedures
- tracibility
- documentation
- etc. 
 
More information can be found in Table A.3 of EN 1090-2:2011-10 or requested via our contact page.