Laboratory Testing

The stringent specifications followed by Interplast in pipe production are certified in its labs with tests specified by European standard 15875, German DIN 16892/93 and Spanish UNE 15875.

The lab distributes only certified pipes that have been quality tested in the following ways:

This is a fixed test that is carried out each time raw materials are received. The flow of the melt of the raw materials is very important in defining the temperature profile of the EXTRUDER and thus homogenization of the material. Then, the small divergence of the pipe’s melt flow certifies the excellent processing of the raw material.

Visual inspection of the outer and inner pipe surface, measurement of outer diameter and measurement of wall thickness by use of certified instruments. These are checks that certify the dimensions carried out throughout production and then in the laboratory.

The pipes that are packed have a cross-linking percentage of at least 65%. At this point the major advantage of method –b should be stressed, as cross-linking is achieved in a natural way. Thus the possibility of a mistake is eliminated; in contrast to the other two methods, where cross-linking is achieved by chemical means (peroxides, radiation).

Specimens from production are kept in the lab stove for 1 hour at 120oC. The result should not present shrinkage after freezing greater than 3% according to DIN 16892. Como-pex pipes present 0.7% shrinkage and Como-pex Oxygen Barrier 0.5% This translates in a particularly low linear expansion of pipes when heated in installations.

This is one of the most important checks and in conjunction with raw material flow it defines the temperature profile and turns of the EXTRUDER. Como-pex pipes display the best possible homogenization, ensuring their long lifespan.

Specimens remaining for 1 hour at 20°C and 95°C, 22, 165 and 1000 hours at 95°C as specified by European standards, German DIN 16892 and Spanish UNE 15875. The 1-hour tests are performed for each final product lot, 22 and 165 hour tests every 2 weeks and 1000 hour test annually for each cross-section.

The company also subjects its pipes to testing in the laboratories of ELOT at 110°C for 8760 hours under pressures defined in EN ISO 15875 and DIN16892.

Pipe specimens are internally scratched at a 10% depth of the wall thickness, their interior is filled with a special chemical that eliminates surface tensions and they are then pressed at 95°C for 1000 hours. The resistance of Como-Pex pipes to this test ensures their reliability even in cases of incorrect treatment during installation (small tears, scrapes, etc.).

By use of a thermal cyclic tester, a test is performed in a special simulator of an actual plumbing installation, which is one of the few used in industrial laboratories of Europe. Hydraulic pressure is applied to a network of Como-Pex pipes and fittings, while the water temperature is alternated every 15 minutes between 20oC and 95oC (thermal shock cycle). After the completion of cycles, all the above tests are performed again, in order to determine and deviation of mechanical and physical-chemical properties of pipes and fittings from their original ones (determination of resistance to ageing).