Transport, storage, installation – a discharge pipe made of polyethylene (PE) goes through a lot before it is finally ready for use. It’s a good thing, then, that Geberit pipes are even able to cope with sub-zero temperatures and heavy impacts with ease.
In former times, there were no international standards for checking the quality of pipes. However, product quality was – and still is – one of the most important sales arguments. To underpin this quality in spite of the missing standards, Geberit defined its own in-house requirements and used these as a basis to check the products. Although internationally recognised standards have since been drawn up, these “Geberit requirements” are, for the most part, still in place today. One of these is what is referred to as the ball drop test. This determines the cold-impact strength, in other words how discharge pipes made of polyethylene react to impacts in sub-zero temperatures.
Robust discharge pipes
The test procedure was explained by Geberit in an advert in the Swiss construction journal from 1967 (683 KB) (German only). Not much has really changed since then. While the pipe section is no longer filled with water and sealed, the deep-freeze is still being used. Here, the pipe section is cooled to -10 °C before being placed in the testing device while still frozen. A steel bolt is then dropped vertically onto the pipe section by one of the specialists from the Materials Laboratory. The muffled impact is followed by a visual inspection of the pipe – thankfully, the frozen pipe section is intact and shows no signs of damage.
But why does Geberit test in sub-zero temperatures? Discharge pipes are often stored outside and are left exposed to the elements. And since pipes can fall to the ground even on a construction site, it wouldn’t be very encouraging if the pipe were damaged and then no longer able to fulfil its purpose. The steel bolt is basically there to simulate a possible impact that the pipe would have to absorb. The weight and speed of the bolt is used to test whether the pipe would remain intact even under harsh conditions. According to the standard requirement, the pipes should be cooled to 0 °C for this purpose. However, the internal Geberit requirements are tougher and require the pipe to be tested to -10 °C.