What is an HDPE pipe used for?

Water on! In the garden, in the yard, in the house, in the garage or wherever you need it - here you will find all information about water pipes. So that the water gets where it should go and the rest stays dry.

Water inlet and water outlet

How does the water get into the house and where does it go? Here you will find information on all aspects of supply and discharge - so that everything stays dry!

Supply lines

Supply systems bring the water to places where it is otherwise not available. The pipes of supply lines are constantly under pressure when the water flows through, in order to guarantee an even flow.

They are made of a thinner material and with a smaller diameter than derivatives, usually made of plastic or copper. Lime and pitting cannot harm plastic, which is why this is usually preferred. There are also strict regulations for water supply lines, e.g. B. the Drinking Water Ordinance and DIN guidelines.


Since drains are only used to drain water, the drainage pipes are not pressurized, but have a larger diameter.
The exact pipe diameter depends on the connected sanitary object.
Sanitary item Diameter of the drain pipe in mm with individual connection
Wash basin, hand basin 40
Kitchen sink, dishwasher, washing machine up to 6 kg, shower, bathtub, urinal, floor drain 50
Washing machine 6-12 kg, floor drain DN70 70
Toilet, floor drain DN 100 110

These pipe diameters are used for individual connections to a downpipe with 110 mm Ø. If several drainage objects are connected to the downpipe on the same line, the next higher pipe diameter is selected. This also applies if the connection line changes direction several times.

A pipe diameter that is too large can be just as problematic as a diameter that is too narrow.

At too large the selected diameters, solids have too little swimming depth. This causes contaminants to be deposited and clog the pipe.

At too tight With the selected diameter, the pipe can be completely filled with water and, through the exclusion of air, lead to the suction of the odor trap.

Downpipes for house drainage must be vented. Instead of the usual roof ventilation, you can install a pipe aerator. This enables ventilation without a roof breakthrough, eliminating leaks. The venting with the pipe aerator takes place automatically. Both at normal pressure and at overpressure, the valve is automatically closed and unpleasant odors are avoided.

In the case of pipe openings in downpipes, an angle of 87 ° is favorable. At this angle, the connection pipe is sufficiently ventilated.

Petrol, oil, grease, acid and other liquids must on no account get into the sewage!

Backflow barriers prevent wastewater from being pushed up the pipes, e.g. B. in heavy rainfall or blocked sewers. Leave the backflow protection to the specialist!

Dirty and rain water

When it comes to house drainage, a distinction is made between waste water and rain water. Wastewater is water that has to be treated due to contamination. Wastewater is led in plastic pipes of various diameters from the drains of the shower, bathtub, toilet, etc. into the sewer system. According to DIN 1986, a distinction is made between the following line sections:

  • The connection pipe leads from the siphon or water drain to the next larger pipe, the downpipe.
  • From the downpipe, the water from the various floors reaches the collecting pipe. The downpipe is vented through the roof so that there is no suction and the water can flow off optimally.
  • The collecting pipe leads the water into the underground pipe.
  • In the underground pipe, the water is fed into the sewer. It is located outside the building. Inspection shafts enable the pipes to be checked and cleaned regularly.
  • For multi-storey houses, bypass lines are required that are used in the event of a sewage build-up.
  • Rainfall pipes direct the rainwater from the roof out of the gutter into a drainage shaft, a barrel, cistern, collecting pipe or underground pipe.

As a rule, wastewater and rainwater are drained away in separate pipe systems. The two are usually not allowed to be brought together at all. If, in exceptional cases, this is the case, one speaks of mixed water systems.

Rainwater, e.g. B. from the roof, in most municipalities it is not allowed to drain it into the sewage system, but has to let it seep away. It should get into the groundwater and thus be preserved in the natural water cycle. Rainwater can also be used excellently around the house: for watering the garden, for flushing the toilet or the washing machine.

The discharge of water into the mixed water or wastewater sewer system must be approved by the competent authority. Depending on how extensive your building project is, you may have to call in a specialist or obtain further permits. Inquire with your competent authority whether this is the case!

DrainageTo the products

Difference between cold water pipes (KWL), HT and KG pipes

In house drainage, a distinction is made between HT and KG pipes. All drain pipes installed in the house are made from gray HT pipes (high temperature pipes). These pipes are made of flame-retardant polypropylene (PP) or polyethylene (PE) and are particularly suitable for cold, hot and aggressive waste water. There are sound-reducing HT pipes, e.g. B. Skolan Safe®.

The red-brown basic pipes, on the other hand, also known as KG pipes (sewer pipes), are made of non-rotting PVC. They are acid and solvent resistant and do not break easily. The green version of the KG pipe from KG 2000 can withstand demanding conditions and is particularly durable.

Cold water pipes

With cold water pipes you can quickly and easily in the house, in the garden or in the yard cold water direct to where it is needed. Cold water pipe systems are ideal in the basement, in the garage or at the carport, on the terrace or in the garden for a fountain, gazebo, fountain or garden pond.

Modern versions made of plastic are very durable, resistant to corrosion and resistant to deposits, algae and bacteria. Stick or screw and water march! And if you want to expand your cold water system, that's also very easy.