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Heating Piping Systems

Heating Piping Systems

Oxygen-tight according to DIN 4726 (sauerstoffdicht nach DIN 4726)

Copper or steel pipes have been used predominantly in the past in heating technology. The sector has since learnt to appreciate the benefits of plastic piping systems. Light weight and high flexibility ensure simple and fast laying.

This is why plastic pipes are used mainly when laying underfloor heating in Germany. There are also a variety of systems available for the application as radiator connecting pipes. The following materials are used:

  • Polypropylene (PP)
  • Crosslinked polyethylene (PE-X)
  • Polybutylene (PB)
  • Polyethylene with higher temperature resistance (PE-RT)
  • Chlorinated polyvinyl chloride (PVC-C)
  • Medium density crosslinked polyethylene (PE-MDX)
  • Multilayer piping systems

As oxygen entering the heating system can result in problems with corrosion to the iron parts (heating boiler, radiators) and therefore has a significant impact upon the life of the system, all the plastic pipe systems have to be oxygen-tight according to DIN 4726.

Cofidence is good - DIN-Geprüft is better!

DIN-Geprüft - Heating Piping Systems

With the accredited and independent certification mark "DIN-Geprüft", DIN CERTCO enables the manufacturer and retailer to convince their customers of the quality of their products and provide the customer with assistance in his purchase decision; as our mark stands world-wide for confidence.

Basis of Testing

The DIN CERTCO certification scheme "Plastic piping and multilayer piping systems for warm water floor heating and radiator connecting systems" is the basis on which the mark is awarded. The scheme is based on the following standards:

  • DIN 4726 "Warm water surface heating systems and radiator connecting systems - Plastics piping systems and multilayer piping systems"
  • DIN EN 15015 "Plastics piping systems - Systems for hot and cold water not intended for human consumption - Performance characteristics for pipes, fittings and their joints"
  • ISO 10508 "Plastics piping systems for hot and cold water installations - Guidance for classification and design"
  • DIN EN ISO 9001 "Quality management systems - Requirements"

As well as on the following mentioned standards specific for material:

Polypropylene pipes (PP)

  • DIN EN ISO 15874 "Plastics piping systems for hot and cold water installations - Polypropylene (PP)" - Parts1, 2, 3 and 5

Crosslinked polyethylene pipes (PE-X)

  • DIN EN ISO 15875 "Plastics piping systems for hot and cold water installations - Crosslinked polyethylene (PE-X)"

Polybutene pipes (PB)

  • DIN EN ISO 15876 Plastics piping systems for hot and cold water installations - Polybutylene (PB)" - Parts 1, 2, 3 and 5

Polyethylene of raised temperature resistance pipes (PE-RT)

  • DIN EN ISO 22391 "Plastics piping systems for hot and cold water installations - Polyethylene of raised temperature resistance (PE-RT)" - Parts 1, 2, 3 and 5

Chlorinated polyvinyl chloride pipes (PVC-C)

  • DIN EN ISO 15877 "Plastics piping systems for hot and cold water installations - Chlorinated poly(vinyl chloride) (PVC-C)"

Crosslinked medium density polyethylene pipes (PE-MDX)

  • DIN 4724 "Plastic piping systems for warm water floor heating systems and radiator pipe connecting - Crosslinked polyethylene of medium density (PE-MDX)"
  • DIN 16894 "Pipes of crosslinked medium density polyethylene (PE-MDX) - General quality requirements and testing"
  • DIN 16895 "Crosslinked medium density polyethylene (PE-MDX) pipes - Dimensions"

Multi-layer composite pipes

  • DIN EN ISO 21003 "Multilayer piping systems for hot and cold water installations inside buildings"
  • DVGW W 542 "Mulitlayer piping systems inside drinking water installations - requirements and testing"

Testing and Assessment

The "DIN-Geprüft" mark is only granted to those piping systems and oxygen barrier materials that are able to prove that they comply with the standards by completing a successful test in a testing laboratory recognised by DIN CERTCO and a subsequent independent assessment.

After a positive assessment, DIN CERTCO issues a certificate that is valid for 5 years. The registration number that clearly identifies the certificate is made up as follows: 3V000.

Third party surveillance

A half-yearly verification test of the product (pipe and fitting) as well as the factory production control (FPC) of the manufacturer follows. The pipes of certified distributors are only subjected to a reduced testing scope.

docx Application Form for the Certification of Products 80 KB Download
pdf Schedule of Fees 227 KB Download
pdf Certifiation Scheme "Plastic piping and multilayer piping systems for warm water floor heating and radiator connecting systems" 1 MB Download
pdf Decision Guide (only available in German) 597 KB Download
pdf General Terms and Conditions 326 KB Download
pdf Brochure Certification of Heating an Airconditioning Products 480 KB Download

FAQ - Frequently Asked Questions

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Which information needs to be added in each packaging unit?

The following information has to be included in each packing unit:

  • smallest permissible bending radii
  • area-related oxygen permeability of ≤ 0.32 mg / (m²·d) at 40 ° C (application class 4) or ≤ 3.60 mg / (m²·d) at 80 ° C (application class 5)
  • Heating water additives, if applicable
  • The pipes must be delivered protected from light. To prevent damage and adverse effects due to UV radiation, the tubes must be stored in the packaging until they are laid. Otherwise, they have to be protected against these influences in other ways. This must be indicated in the product documentation and in the leaflet.

Which changes result from the new certification scheme (Edition: 2019-03)

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.

How to proof that the oxygen barrier materials made of EVOH are thermally stable?

Oxygen barrier materials made of plastic must be sufficiently thermally stabilized if they are used in a particular piping system as specified in Annex C through I of the certification scheme. They are considered to be thermally stable if the continuous operating temperature (corresponding to a stress duration of 50 years) does not exceed 70 °C.

If manufacturers of plastic piping systems use oxygen barrier materials with a valid DIN certification in accordance with Annex J, it shall be considered as proof of thermal stability.

How should test reports be sent to ensure a smoth processing of certification procedures?

In order to process the certification procedures, DIN CERTCO requires all the necessary inspection and test reports (pipe, connectors, system, O2) on schedule.

Ideally, the involved testing laboratories should always send these reports as PDF files to the customers and in parallel to the responsible DIN CERTCO customer service. This saves paper, is quick and everyone has the complete information for further processing of the certification procedures.

Certificate holder and testing laboratories

Certificate Holder

Heating piping systems

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Certificate Holder

Oxygen barrier materials

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Testing Laboratories

Heating piping systems

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