Workshop Pre-Assembly

The preconditions for workshop pre-assembly are the following:

• Quality Management certified according to DIN EN ISO 9001:2000
• Environment Management certified according to DIN EN ISO 14001 
• Pressure Equipment Directive 97/23/EG (DGRL)

• Welder's certificate: ISO3834-2 (EN 729-2) and  AD2000 HPO
• Verification of all welding procedures: EN 288-3 / AD2000 HP2/1 / 97/23/EG
• Welding supervision: EN 719
• Welder tested according to the DGRL: EN 287-1 / AD2000 HP3
• Machine operator tested according to the DGRL: EN 1418 / AD2000 HP3
• Marking-transfer agreement with the TÜV-Nord
• Certified inspector for endoscopy and evaluation of radiographies

• According to Pressure Equipment Directive complete with operating instructions 97/23/EC Art. 3 Para.3 (Standard)
• As of Category 1 with CE Marking
• Models, drawings and part lists using the CAE-System (DXF format)
• Goods intake documentation to be checked against the specification of the order
• Manufacture-related documentation (material, surface finish, dimensional accuracy)
• Weld documentation with as-built one-line isometry, recorded weld parameters and endoscopy

• Final test carried out by our Quality Assurance Dept. (standard)
• Final test according to pressure equipment directive (or by specified institution)
• Functional wet test run at test rig according to the customer's requirements

Standardised workshop pre-assemblies are carried out on valve blocks, swing-bend panels, pipe fences and CIP units.

Concerning valve block pre-assembly, we take specific measures in order to obtain functional safety of the valves when used within valve blocks under specific operating conditions. Thus, the valve housings, for instance, are aligned to each other on a dressing plate, pipe fittings or reducers between two valve rows are brought to equal length, inner tensioning mandrels are used and care is taken to bring in as low as possible amounts of heat during machine welding. 

From long years experience we know already during construction the crucial locations under specific operating conditions (temperature, pressure, connection to the plant) and check these parameters using the stress analysis programme Cäsar II. That way we are able to take corrective measures by modifying the fixing conditions, piping and / or by use of our expansion compensators.

In case of queries please use our questionnaire (Excel file), that describes our standard and possible options.

Besides valve technology, the use of swing-bend panels and pipe fences is common practice. This is the reason why we have defined standards in this respect which allows us to fulfil your requirements at good quality and low cost.

Where ever our valves are used in a plant, CIP units will be needed. We therefore have standardised sections of these units in pre-defined and field-tested modules. In this way we are able to quickly respond to your individual requirements. It goes without saying that we also manufacture pre-assemblies or line-specific units according to your specifications.