Sewer systems made of profiled Krah pipes have been used for more than 35 years in all areas of local and industrial drainage.

The Krah group offers a modern sewer pipe program with manholes, fittings, and safe pipe joint systems for the planning of sewer treatment plants.

Gravity Pipes made out of PE80 / PE100 and polypropylene can have inner diameters ranging from DN/ID 300 mm to DN/ID 5000 mm. The standard length of 6m enables easy transport, quick handling and less jointing.

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However, shorter pipes can be manufactured as well. The lifetime of the pipes is estimated to be more than 100 years. Gravity Pipes are produced according to the following standards:

  • DIN16961
  • EN13476
  • ASTM F894
  • NBR7373
  • JIS_K6780

By using a profiled design pipe, the weight can be reduced up to 65% compared to a solid wall pipe with the same ring stiffness! There are 5 different profiles possible including a solid wall. Usual fields of application are: Sewage or drainage systems, relining, outfall pipes, reservoirs and storm water tanks or sometimes also industrial uses. 

Storm Drain

Krah is a competent partner for system components for drainage and degassing of landfill sites.

Many landfill sites have been successfully equipped with profiled drain pipes and manholes.
Krahs developments have set new standards for soil and ground water protection. Drain shafts with control systems are available in diameters of up to DN/ID 5000 mm.

Pressure Pipes

Pressure pipe diameters may range from DN/ID 300 up to DN/ ID 5000 mm made either of homogenous polyethylene, polypropylene or a compound of polyethylene reinforced with fibers to unite the well-known properties of thermoplastics with the significant characteristics of fibers.

Fields of application spread from potable to industrial uses or also special applications. Pressure may range up to 10 or 16 bar.

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PE100 has a MRS of 10 N/mm² and corresponds to the following international standards:

  • ISO 4427
  • DIN 16961
  • DIN PAS 1065
  • SPEC 14001

Dimensions and their corresponding weights: Bigger diameters are possible on request.

PE-GF 200 has a MRS of 20 N/mm² and corresponds to the following international standards:

  • ISO/CD 29561
  • ASTM F2720
  • DIN SPEC 19674-1
  • DIN SPEC 19674-2

Dimensions and their corresponding weights: Bigger diameters are possible on request.

Marine Application

Water outlets are used for the discharge of liquid and gaseous substances at the base of rivers and the sea.

For the construction and operation of such pipelines Krah pipes offer considerable advantages, such as the elasticity of the pipeline and therefore optimum adaptation to the area, low weight, secure and strong jointing technology and seawater resistance.

The pipe stiffness is exactly adapted to the respective requirements because the appropriate profiles are selected for every individual project.



Manholes are used for maintenance and inspection of piping systems. Basically they can be clustered into two main categories.
System shafts are used for smaller dimensions whereas tangential shafts are used for rather larger dimensions. They basically differ in their position/location towards the pipe.
All Manholes are designed in a cylindrical shape. They are designed to take full highway traffic load (HLC60) where the reinforced concrete top plate rests directly onto the vertical wall of the construction. PEHD Manholes and chambers can also be installed in areas of high ground water levels.


Fittings can be reductions, branches or bends. All are produced from pipes of the type VW or SQ. Their design corresponds to the required stiffness and the chosen welding factors.
Any fitting end can be chosen and all fittings can be jointed with every technique we offer. Certainly, the fittings hold the identical excellent characteristics as our pipes.


Bends can be manufactured and segmented in different angles and the related radius of the bend to the pipe diameter can be selected independently.
Basically every angle can be produced.


Reductions can be made both centrically and eccentrically so that the reductions will always meet the requirements.
For standard reductions the maximum difference in diameter is 200mm, but any other differences can be manufactured as well.


Branches can be manufactured and delivered in every type and form.
The angle can be adapted individually from 15° to 90° as well as the ends and the respective segment lengths.

House connection branch

PE pipe systems fulfill the highest requirements regarding tightness, long lifetime and installation.

These high demands are being strictly and consequently met by HAS-fitting. Suitable for a new installation as well as a later integration in an open construction, the house connection pipes and lateral pipes in diameters DN 150(OD 160 SDR 17,6) and DN 200 (OD 225 SDR17,6) can easily, quickly and economically be jointed to the main pipe out of PE.

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The HAS-fitting DN 150 is designed for connection of PE pipes OD 160 SDR 17,6 to all profiled PE pipes with a total wall thickness up to 140mm and to PE solid wall pipes up from OD225 SDR 17,6. The HENZE HAS-fitting DN 200 is designed for connection of PE pipes DA 225 SDR 17,6 to all profiled PE pipes with a total wall thickness up to 140mm and to PE solid wall pipes up from OD355 SDR 17,6.

All advantages at one glance:

  • No special tools necessary for installation
  • Easy and quick assembling
  • Suitable for all solid wall and profiled pipes out of PE
  • Durably tight thanks to welding
  • For immediate use
  • High security by automatization
  • Shifting security and force absorption thanks to welding of the complete pipe wall
  • Robust design
  • No inside protruding elements thanks to concave peeling

Download Brochure - HAS - House connection fitting

Tanks and Apparatus

Tanks can be filled with various volumes (liquid, solid, organic, inorganic). A major advantage of these storage tanks is their varying wall thickness : the bottom is made from thick wall material while the top is rather thin.

This enables an economic manufacturing, stability and an uncomplicated handling.Basically the tanks are large-volume custom-designed tanks with a capacity of 1m³ to 150m³. The tanks are completely tailor made and can be extended easily even after they have been finished.

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All parts can be produced out of the same material and they are usually welded to the main tank so that it forms a completely
homogenous unit. Nearly all ideas of the customer and the planning engineers can be fulfilled.
After the fabrication of a tank or even a complex apparatus is completed the unit will be shipped to the construction site. The installation
time is very short and the handling is very easy due to the light weight and the robust design.

The designs of the tanks are mainly according to DVS2205 and EN12573 or any other specific application guidelines. To facilitate
the calculation, Krah has a special software program. One of the big advantages is that the maintenance cost of the complete system is
very low and the cleaning is also easy and quick. In general,every storage tank is built with a round cylinder shell and
can have different heights. In the following table the main sizes are mentioned. In addition we can produce every diameter in the range
of 1000mm up to 5000mm internal diameter. The range of wall thicknesses can vary from minimum 5mm to maximum 250mm.

Also storm water tanks are available.

Contact Us

  • Krah Group
  • +49 (27 41) - 97 64 0
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