TA-Luft: Our flange connections meet all requirements

At the end of 2021, the new version of the First General Administrative Regulation on the Federal Immission Control Act (BImSchG) came into force. For many, this is better known as the "Technical Instructions on Air Quality Control - TA-Luft".

The main purpose of this law is essentially to protect people, animals and plants from harmful environmental effects and to prevent them from occurring.

Three verification methods are equivalent and permissible for providing proof of air tightness:

  • Computational proof
  • Type-based component test
  • Individual case-by-case test


Piping systems with special materials (e.g. steel/enamel, steel with PTFE or PFA inliner) are excluded from DIN EN 1591-1. Consequently, it is not currently possible to provide mathematical proof in accordance with the above standard. Therefore, proof of the tightness of the joints is provided by type-based component tests. This is done in cooperation with an accredited testing laboratory.

According to the amended TA-Luft, the tightness class L0.01 with the corresponding specific leakage rate ≤ 0.01 mg/(s∙m) for the test medium helium must be complied with for technically tight flange connections. For the test, the most unfavorable connection in the respective pipe class is selected; this usually corresponds to the nominal size DN40.

Proof of tightness across the connection is determined using a standardized test procedure. The maximum operating temperature and the minimum/maximum operating pressure are tested. This proof must be provided for each system. We have also included the minimum operating temperature in the test. The leakage criterion of TA Luft of ≤ 0.01 mg/(s∙m) was not exceeded in the relevant test.

We have thus provided evidence of compliance with the requirements and thus make a significant contribution to sustainable environmental protection. The tested compound can be considered a high-quality sealing system in the sense of TA Luft.

The certified proof of tightness is an essential base. The qualified personnel for assembly of the piping system must also be considered. On request, we can qualify the assembly personnel according to the required DIN EN 1591-4, so the legal and company-specific requirements can be reliably met in demanding production operations.

Transition period: With beginning of December 1, 2025, only flange connections (for media covered by TA-Luft) for which proof of tightness is available allowed to be used.

Existing flange connections: These may continue to be used until they are replaced by new flange connections in a 1-by-1 exchange.