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Max-von-Laue-Str. 23
30966 Hemmingen

 Tel: +49 511 943 70-0
Fax: +49 511 943 70-70
@: info@fernwaerme.de



Quality tests of district heating systems

The recording of characteristic values of materials determines the quality standard. Quality standards of plastic materials, PUR-foams on plastic bonded pipes (KMR or KVMR), and joint systems can be defined. Our test laboratory is officially recognised by DIN CERTCO for examining EN 253, EN 489, EN 448, EN 488 and EN 254 and other standards. Furthermore we are able to test concerning EN 15632 and EN 14419.

Quality testing is necessary:

Quality testing with documentation is recommended during production or when laying plastic bonded pipes. The Fernwärme-Forschungsinstitut with its experience since 1980 as neutral expert who offers pragmatic and cost conscious testing of product quality on the latest standard in order to avoid faults in time which may become very costly at a later stage.

Therefore, a representative choice of samples of each plastic bonded pipe of each production should undergo a quality testing according to the valid standards (EN 253, EN 448, EN 488, EN 489 as well as the guide line FW 401).


The standard requirements of the foam quality in respect to 

  • water absorption,

  • size of the cells, 

  • pressure resistance and

  • foam density are determined

Defining the size of the cells by light microscope Recording the pressure density of a foam sample according to EN 253 at the laboratory of the FFI

Water absorption in order to define the foam quality

For test samples, which are delivered to the Institute before 11.00 a.m., a result is available at the same day.


determination of the foam density by a precision scale 

Furthermore, on request the requirements of the compound quality in connection with the

  • axial shear density can be tested, as well as the

  • coaxial tolerance.

Determining the axial shear density of a plastic bonded pipe DN 500/670

Checking the co-axial 
tolerance at a plastic bonded pipe

Checking the wall 
thickness of the PE-jacket 

The geometric tolerances of the samples are tested, especially the

  • wall thickness of the medium pipe / PE-jacket (picture 7) and the 

  • positioning of the leak warning wires (picture 8).

Checking the wiring of the leak 
warning system inside a plastic bonded pipe

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- 2017 -