TehoDrain procedure

Gravity separation function as a drainage technique and the performance principle of the TehoDrain drain pipe.

The performance principle of a drain pipe, that functions on the basis of gravity separation function.  As a technique gravity separation function offers clear advances compared to traditional perforated drain pipes and filter solutions implemented with Geo-textiles:

  • reliability
  • effective performance
  • maintenance freedom
  • long-term durability and life cycle.

Drain pipes that function on the basis of gravity separation function do not clog and they are maintenance-free. When the water surface rises into the protected channel of the drain pipe, a water tower is formed from where the water flows inside the pipe.

salaojaputki salaojaputket

In this technology the separation of the particles from the water happens through gravity. Because of this, with the water particles or grit are not transmitted into the pipe, as they could cause a blockage.

Water is not filtrated through small holes in the pipe, or through Geo-textiles, or through the fine material that is in the pit. Gravity separates the most heavy particles, and they do not arise with the water to the pipe. Filters function always as a temporary solution and they demand to be changed. They become saturated from fine particles and lose their water permeability function, which means that the effectiveness of drain pipes is lost very quickly. This means uncontrollable rise of water in the surrounding soil.

salaojaputket salaojaputki tyyppikuva

In a drain pipe that functions the water level is always in control: the pipe draws water in when the water level is on the same level as the water inlets. Because the technology is not based on filtering, also the same kind of loss in effectiveness during time does not occur.

As a filling material of the pit it is recommended a 8-16 crushed stone, which is very well water permeable, where the water is directed quickly from the ground to the pipe. A 110mm TehoDrain drain pipe´s effectiveness equates the effectiveness of a 280mm drain pipe.

Self-cleansing: Inside the pipe we get cutting characteristics, when the water flow grows ≥ 0,3 l/s. In that case it releases the particles that were left in the pipe for example in the installation process, as well as very light humusparticles, if they flow in the pipe with the water.


According to testing, even 1mm of sand is rinsed off. Because the pipe is closed and solid, it leads out the water away effectively. The pipe does not water the ground, as the water does not flow back into the soil.

Compact and non-silting pipe solves this problem preventatively. The technology has a long history and it was first used in 1980.

PeTec Engineering Oy, who manufactures TehoDrain, has to show reliable references, long lasting experience of the functionality of this technology, as well as examples of numerous satisfied customers.

The product and the technology has been tested at the Chalmers University of Applied Sciences, as well as by SP in Sweden.


TehoDrain product information

TehoDrain drain pipe has been manufactured from friendly PP-plastic, with joints as part of the factory settings.

  • Pipe diameter 110mm
  • Watershed: 50 cm/m
  • Inlet openings: 10x60mm
  • Self-cleansing: Inside the pipe the cutting characteristics get activated, when there is a ≥ 0,3 l/s water flow. Because of the bottom design of the flow canal, the pipe is self-cleansing.
  • Ring stiffness: equals SN8 – classification.
  • Matching with ordinary 110m parts. For bed drain pipes, extraction pipes, as well as for curves and other parts, ordinary ground sewer parts fit.