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Oxygen tightness according to DIN 4726 - New certification scheme was published


Piping System

For many years, the planners and installers domestically and in other countries have been relying on the DIN certification for plastic piping and multilayer piping systems (heating piping systems) and the “DIN-Geprüft” mark. In particular, the oxygen tightness in accordance with DIN 4726 stands internationally for a durable and undisturbed operation of surface-embedded heating and cooling systems in accordance with DIN EN 1264 and has therefore been established as a word mark. Whether in Europe or Asia, the DIN certificate opens up access to local markets worldwide for you.

But even good things can get better. The responsible standards committee NA 041-01-16 AA within the DIN Deutsches Institut für Normung e. V. has revised DIN 4726. The valid version was published in October 2017. It resulted in the following main changes in comparison with the previous version 2008-10 in addition to an editorial revision.

Overview of the main changes

  • Adoption of requirements for thermal stability of oxygen barrier layer materials, as well as adoption of a corresponding testing procedure
  • Adoption of requirements for thickness of the oxygen barrier layer, as well as adoption of a corresponding testing procedure
  • Revision of the requirements for oxygen tightness as well as revision of the testing procedure for oxygen tightness by supplementing an optional test on pipes with an outer diameter > 32 mm
  • Revision of the requirements for heating water additives - compatibility with plastic pipes according to this standard
  • Revision of the testing procedure for homogeneity
  • Revision of the requirements for labelling and information (to date packaging leaflet)

We have incorporated these changes together with our experience exchange group from the testing laboratories recognized by us into the DIN certification scheme “Plastic piping and multilayer piping systems for warm water floor heating and radiator connecting systems" (edition: 2019-03).

It is possible to access this as a PDF document on our website at www.dincertco.de . You will also find the current application documents for the certification including the valid schedule of fees as well as all valid certificate holders.

Overview of the main changes

  • Adoption of the revised requirements of DIN 4726:2017-10, DIN EN ISO 15874:2018-11, DIN EN ISO 15876:2017-06 and DIN EN ISO 9001:2015-1
  • Specification of requirements for testing, certification, surveillance, changes and factory production control according to the decision book by the experience exchange circle for testing laboratories (EK-RL) from DIN CERTCO
  • Introduction of a certification of oxygen barrier materials made from EVOH
  • Editorial changes

What concrete changes will there be for you?

  • The new certification scheme is to be applied bindingly for all new piping systems to be tested for which the DIN mark is to be applied.
  • All existing DIN certificates, which are based on the current certification scheme (as of: 2015-01) must be converted to the new certification scheme no later than 2020-06. On application, however, this can also be done beforehand.
  • Inspection, modification, or extension of DIN-certified products must be performed in accordance with the new certification scheme.
  • All products must provide proof of conformity with the currently valid standards in the form of a current test and inspection report by a testing laboratory approved by us. This includes the fol-lowing items:
    - pipe testing incl. oxygen tightness testing in accordance with DIN 4726:2017-10
    - fitting testing
    - system testing (e.g. in case of initial certifications)
    - The factory production control (FPC) of the manufacturer
  • Please ensure that the test and inspection report also refers to the valid certification scheme incl. issue date.
  • Furthermore, in order to minimize the processing time, the testing laboratory should send you and us all the necessary reports directly as a PDF file.

We are ready. Our experts know the changes in detail and are happy to answer your specific questions.

Dr. Jürgen Heinemann
+49 30 7562-1105
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