Gravity sewers are available in every imaginable size.
We are authorized to carry out pressure tests up to a diameter of 2500 millimeters.
There are all imaginable cross-sectional shapes for gravity sewers.
We will take a closer look at the most important cross-sectional shapes.
Circular profiles are the most frequently used profiles.
As the name suggests, this profile is circular and may have only a certain ovality after installation, which differs depending on the manufacturer.
Egg profiles have a narrow cross-section, as shown in the picture, in order to maintain the flow rate even with little water.
It is often used in mixed water systems to cope with the large amounts of water in prolonged rain.
In some cases, however, special profiles are also installed, whereby each of these profiles has advantages and disadvantages.
The pressure test of all this shapes is not a problem, although you have to use your ingenuity in some cases.
1. Pressure test with medium air (overpressure)
The most frequently used method of pressure testing is with the test medium air.
In this case, as shown in the picture, the two ends of the pipe sealed with sealing pads and then be filled with air with an overpressure.
If the overpressure in the pipeline lasts for a certain length of time the line is called tight-proof. (More precisely, the examiner can explain this to you on the site)
2. Pressure test with medium water
If a pressure test with air isn't sufficiently meaningful, or if the judge requires an alternative test medium in case of litigation, it is possible to fill the pipeline with water, make a water column an then measure if the water column is maintained.
However, this method is more complex and thus more expensive than the method with the medium air.
The pressure test on a shaft is carried out with the medium water.
In this case is a depth probe positioned at the deepest point of the shaft and additionally attached a level gauge.
This monitors the constant of the level and responds to the smallest changes.
The pressure test on a container differs only slightly from a shaft.
However, there are many different types of containers such as: