Tap water – is it really clean?

We say yes – that is, if planners, architects, installers and wholesalers make drinking water hygiene “their business”.

Clean drinking water is one of the most precious and important commodities there is. We use it every day: when consuming beverages, preparing food, caring for infants, or tending to our personal hygiene. We do all this without really thinking about it and with faith in the quality of our drinking water. Water is, after all, supposed to be the most strictly monitored of all foodstuffs. Nevertheless, water is often polluted, and it is a known source of serious illnesses. According to a report by the European Centre for Disease Prevention and Control (ECDC), in 2012 alone a total of 5,852 people came down with an illness (such as Legionnaires’ disease, for example) as a result of contaminated water. The number of undisclosed cases is presumably considerably higher, since Legionella bacteria often remain undetected as a cause of pneumonia.

Clear guidelines: the EU DIN EN 806 standard

In Germany, the cleanliness of drinking water is regulated according to the Drinking Water Regulation (Trinkwasserverordnung) that came into effect in 2001. This regulation stipulates that any water that is used must not result in any damage to human health. The EU also provides clear guidelines in this regard. The “Codes of practice for drinking water installations” formulated in the DIN EN 803 standard are intended to ensure that drinking water is always healthy to drink.

Practical experience has shown that mistakes made during the planning process or construction, or later on during operation or maintenance procedures, can have a seriously adverse effect on drinking water quality. The consequence: the requirements imposed for drinking water are no longer fulfilled, and harmful effects on health may result. The EU provides operational, structural and procedural rules in its directive which, when optimally combined with one another, are intended to prevent the formation of hazardous germs in drinking water.

For this reason, one must ensure even before a project begins that it is executed correctly. Since pipes are usually installed where they are difficult to access – in installation shafts, pre-wall installations or under plaster – rectifying a lack of adequate insulation is usually very labour and cost-intensive.

The solution lies in the details

The factors that often put the quality of drinking water at risk include, as well as improper installation of cold and hot water pipes, inadequate or missing insulation. This is also true of pipe fittings, branch fittings, and pipe supports where there is a break in the insulation. As a general rule, the temperature should not exceed 25 °C in cold water pipes or be less than 60 °C in hot water pipes. To ensure that these limits are observed, DIN EN 806-2 provides that pipes for cold drinking water may not run next to hot water sources, such as heating ducts, or through heated areas without the appropriate insulation. Adequate insulation is required especially when, for structural reasons, the cold and hot water pipes run through a shared supply duct. Conversely, hot water pipes must be protected from the effects of cold. The insulation must be just as thick as the outer pipe diameter. Its minimum thickness, however, is subject to country-specific requirements.


Tested materials for safety all along the line

Naturally, the correct selection of insulation material also plays a crucial role. Rubber insulating materials made by Kaimann are the ideal choice for insulation. Thanks to their closed-cell structure, these elastomeric insulating materials offer high diffusion resistance with μ-values of up to 10,000 and are therefore resistant to moisture and prevent water condensation and corrosion – the be-all and end-all of drinking water pipe insulation. Open-cell foam and fibrous structures soak up water like a sponge, thereby compromising the insulating properties of the insulation. Even when they are manually installed with the utmost care, leaks in the external water vapour barrier and water penetration into the insulation are often unavoidable.

Kaiflex insulating materials have an even greater advantage over open-cell materials. Owing to the extremely fine structure of the individual closed cells, not even scratches on the surface of the insulating material can cause damage to adjacent units, and the moisture resistance of the material is preserved despite the damage.

But Kaiflex products excel by virtue not only of their resistance to moisture but also because of their low thermal conductivity. With a lambda value of up to 0.033 W/(m·K), the temperatures specified above for hot and cold water are reliably maintained, thereby preventing legionella formation. For our rubber insulating materials we offer practically integrated system solutions: insulating materials along with pipe supports and the appropriate adhesives for guaranteed continuous, end-to-end insulation.