Our Certifications


The quality of the completed work, the qualification and reliability of the employees and the performance of KARL WEISS Technologies GmbH can be proven by numerous certificates.

Quality at the highest level
DIN EN ISO 9001 forms the basis for the continuous improvement process of the company's internal quality management system. Our high quality requirements are met by consistent application of our quality management in all areas of the company and is supported by all employees.

Sustainable development and social responsibility
Environmentally responsible management is more important than ever before. The environmental management system according to DIN EN ISO 14001 enables KARL WEISS Technologies GmbH to develop and implement environmental policy and corresponding objectives.

Proven qualification for open-trench pipeline construction
In addition to highly developed materials and processes, qualified employees are the most important key resource for building, operating and expanding high-performance pipeline networks. For this, we are certified as a specialist company by DVGW according to worksheet GW 301 (groups G 1: ge, pe, st and W 1: az, ge,pe, pvc, st).

Proven qualification for trenchless pipeline construction
KARL WEISS Technologies GmbH is certified by DVGW according to worksheet GW 302 as a specialist company for the trenchless reloading (group GN1) and rehabilitation (group R1 and group R2) of non-operational pipelines gas and water pipelines.

Systematic work safety in construction
We attach great importance to health and safety. For this, we use the AMS BAU sector-specific occupational health and safety management system and are certified by the professional association of the construction industry.

Expertise and reliability in sewer construction
With the fulfillment of the requirements of the quality and test provisions RAL-GZ 961, KARL WEISS can demonstrate special technical qualifications (technical knowledge, technical performance and reliability). We are the quality mark holders of the following assessment groups: AK1, VP, S21.1, I, R and D

For the protection of water resources
TÜV Rheinland AG has certified KARL WEISS Technologies GmbH as a specialist company in the sense of the Federal Water Act. As a result, we are qualified to manufacture bored piles as well as to install, set up, repair, install and clean drainage systems in the area of LAU and HBV systems.

Proof of competence for welding engineering manufacturing companies
The ISO 3834 standard specifies the principles for quality assurance of welded products. Our corresponding certification according to ISO 3834 documents the high quality of our welded products.

Welding of steel structures
Welding certificate in accordance with EN 1090-1 for the welding of steel structures according to DIN EN 1090-2, EXC 2. This ensures the traceability of the materials used as well as the presence of qualified welding instructions, tested welders and welding engineers.

Conformity of intern factory production control
The intern factory production control defines the continuous self-monitoring of our welded products. This ensures that the load bearing components and kits for steel bearers placed on the market have the declared performance characteristics.

Liquid soil according to RAL quality mark 507
KARL WEISS Technologies GmbH is the bearer of the RAL quality mark 507 - Liquid Soil (assessment group A2, H4) and is authorized to manufacture and install liquid soil. There is a close partnership with Berliner Flüssigboden GmbH.

Association for the Prequalification of Construction Companies
The Association for the Prequalification of Construction Companies operates a prequalification system for companies in the construction and construction industry in the award of public building contracts in Germany. KARL WEISS Technologies GmbH pre-qualifies for professional knowledge, reliability and performance.