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Quality is the sum of all properties that make products suitable for customers.

Creating confidence in the quality of our products is our formula for success. Our paramount goal is ensuring the quality of our products and services. In order to meet these requirements, we constantly analyse process sequences and consistently implement the measures required for process improvement.

To support all measures, we make use of our DIN EN ISO 9001 : 2008 quality management system, which has been in use for many years and which is constantly monitored and improved in close cooperation with our auditors. High requirements are demanded of manufacturing products for pressure vessel components.

Application of modern and state-of-the-art equipment and employment of qualified personnel is required for all production stages in order to be prepared for the challenges of this market. This qualification is documented in the Certificate according to EC Pressure Equipment Directive 97/23/EC.

Destructive and non-destructive tests and welding engineering are an integral part of our production processes.

For verification of this qualification, our company is also certified in accordance with DIN EN ISO 3834-2.

The following certificates are available for download:

DIN EN ISO 9001-2008

Certificate 97-23-EG

DIN EN ISO 3834-2 Fusion welding + NDT Testing (Document in German)


Protection of the environment is an integral part of our company philosophy and thus an obligation to not only keep, but to consolidate and extend the standards we achieved. From 17 to 19 March 2009, a repeat audit of our environmental management system was performed by an environmental auditor from TÜV Nord Cert GmbH with regard to requirements for environmental protection according to DIN EN ISO 14001. This audit included the entire site in Ruenderoth with its four divisions: Special steel, Special steel castings including forging ingots, Investment castings and Surface engineering. It was verified that the policies specified in the environmental management system, the environmental goals, and the corresponding programmes were implemented in due time.

DIN EN ISO 14001 : 2015

Energy management

Efficient energy management is not only an end in itself. It is part of the corporate claim to save resources and protect the environment.

Our well-functioning energy management system was enhanced in accordance with the requirements of
the DIN EN 50001 : 2011. The system was last audited and certified in November 2017 by the German Technical Service organisation TÜV. The assessment by the responsible TÜV Nord Cert GmbH confirms the ambitious energy management actively operated by Dörrenberg at all sites for many years. This includes the introduction of energy management at an operational level. A number of measures significantly increased the energy efficiency of the overall company. The employees make an important contribution: they show their commitment at all levels in the systematic development and implementation of energy efficiency measures.

DIN EN 50001 : 2011

© Dörrenberg 2013