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Live performance of the new KR800-MAX plant

Krah high-performance production plant KR800-MAX was successfully accepted - Pipe of DN/ID1000mm, SN8 was extruded with 1300kg/hr


In the course of a machine acceptance more than 20 international companies visited the little village Schutzbach in the Westerwald, Germany – where profiled pipe production plants have been successfully developed and produced for more than 30 years – and are subsequently put into operation by Krah Advanced Technologies GmbH – shortly KAT GmbH.

But with this new machine the self-defined performance target was clearly exceeded. The production performance has been steadily increased throughout the past years. This time the designers even impressed the management board and all customers / stakeholders, as it has been managed for the first time ever to produce a profiled pipe DN/ID1000mm, SN8 according to ISO9969 with bright, co-extruded inner layer incl. electro-fusion and spigot with a production output of up to 1300kg/hr. As acceptance material the HE3490LS and HE3492-LS-H from Borouge / Borealis were used for the inspection-friendly inner layer. The customers were extremely impressed when the whole pipe was finished in just a few minutes, including socket and spigot.

The extrusion heart of the new plant KR800-MAX consists of a KraussMaffei extruder 125x36D and a self-made co-extruder which was effectively included into the plant. Every extruder is equipped with a gravimeter for two components each. The in-house control system controls and visualizes the whole plant. The gas and energy consumption can be pursued precisely on screen.

In general the machine appeared very tidy and open for additions. Additions may include the development of other materials like reinforced ties or the production of square profiles. Generally round profiles are extruded since there have been a lot of optimizations in the past weeks / months to produce pipes in larger diameters even easier while simultaneously fulfilling the required stiffnesses. The maximum profile diameter is 110mm for round and 80mm for square profiles. There is a special profile for outfall and sea water intake line applications, which make the usage of such pipes for these applications even more cost-effective and save.

The customer will solely produce outfall pipes for the first 1.5 years which are connected to each other by an electro-fusion fitting.
Due to the new mass distribution valve the pipe endings are manufactured homogenously with only one die head – the second one will be opened at the required time – thus the start-up waste will be reduced to 5 kg besides the better quality and look.

Another feature of the plant KR800-MAX is the production of homogenous solid wall pipes with a wall thickness of up to 300mm – without any sagging problems and with the above-mentioned high production output. The plant can produce bi-directionally and has been equipped with a special, energy-saving IR-heating.
During the live demonstration the changing from a profiled pipe with SN8 to a homogenous solid wall pipe with a wall thickness of 30mm could be done in only 7 minutes.

Besides the high performance the control-, operating and evaluation software has been greatly exceeded, which is the effect of personnel increase of programmers. The production plant is able to measure, record and evaluate all direct costs like time, downtimes, gas, material and energy consumption. This can be done per kilo, pipe, day or month. The evaluations are directly shown on the machine or on smartphone and computer through the program “Pontis” – which is the “bridge” between plant and operator.

Via RFID chips and cards nearly all product-related dates can be measured and saved per pipe, which fulfils the demand for product traceability.

KR800-MAX - Profile 1KR800-MAX - Profile 1

With this new production plant KR800-MAX the Krah technology is well prepared for the future and ready to stand against global copy-cats.

The customers were highly satisfied and 3 days later the plant was already dismantled and ready for dispatch to the customer in Near East, where it will highly efficiently produce pipes in about 2 months. The installation of such a plant lasts max. 10 working days and doesn’t need a fundament which makes the machine very “moveable” and can “follow” pipe projects.

Alexander Krah
CEO Krah Pipes GmbH & Co. KG,

Certification of Quality & Performance

Certification of Quality & Performance

The global situation of large diameter plastic pipe producers and machine suppliers is steadily increasing. Unfortunately we had to notice that many producers say they are producing Krah pipes only because they produce similar pipes on our machines or even on copies of our production plants.

I have been confronted with so-called “Krah pipes” myself, which neither correspond to our demands nor to international norms. Furthermore I was lead to “Krah production plants” (supposedly produced in China in our name), which didn’t even come close to producing sustainable, accurate Krah system components.

Of course we feel flattered when not only our products but also our name ‘Krah’ is copied which globally stands for good quality. However, we decided to even raise our quality standard and to give producers the possibility to get certified of really having a real Krah approved quality product. And also to have the opportunity to advertise with the certificate on the market. This also serves to integrate a clear quality hurdle in public tenders – products of high quality can be clearly distinguished from cheap products with low quality.
To enable this we have planned an inspection concept together with an external auditor which screens the pipe production company and tests the products complementing to international norms.
Parts of the annual testing are:

  • Condition of the production means ( production plant)
  • Inspection of machine by maintenance plan / maintenance intervals
  • General condition of production plant and work conditions of employers
  • Testing of the quality control system and if it corresponds to the current requirements
  • Inspection of the quality laboratory ( Equipment, test interval and maintenance)
  • Random sample testing of the incoming goods inspection (raw material) and the required documentation
  • Qualitative assessment of the used raw material
  • Random testing of size accuracy of Krah pipe products which are about to be dispatched or are on stock.
  • Testing of the marking of non-accurate Krah pipes products
  • Testing of qualification and further training for employees with respect to Krah pipe products and their quality
  • Successful questioning and evaluation of the management with respect to production quality, production conditions and the social responsibility of the entrepreneur for employers, customers, suppliers and the environment.

Krah certificate of quality and performance

Only companies that pass these random tests are allowed to advertise its pipe products with the Krah pipes certificate. The certificate has a standard term of one year and usually ends with the 30th June.

Furthermore the certified companies are named on and and in every issue of our newsletter “ImProfil”.  On many global marketing measures of Krah Pipes Germany explicit indications for the certified companies can be found.

For some companies the test procedure has already begun so we can issue the first certificates already in May 2017.

Alexander Krah
CEO-Krah Pipes GmbH & Co KG

Storm water retention

Storm water retention

Draw of storm water retentionDraw of storm water retention

Not only global warming but also population growth lead to a change of the usual conditions in many areas, which require a reaction to the “new”, but also necessary and current building measures lead to changes.
One sector of these changes are building measures which are realized in gaps between buildings or on open spaces (e.g. through sealing) and therefore lead to increasing water quantities which have to be drained, which in cases of average and heavy rainfalls the existing sewerage network cannot absorb. Underground buffers are a widespread solution here, because they don’t overload the sewerage system due to a delay of derivation.
In most cases the network operator determines the conditions for the opening, he defines who, when and how much can be fed to the network, since an overload can lead to widespread damage, e.g. through overflowing.
For such changes the installation of underground restraint systems, especially of storm water retention from PE-HD, has proved, since discharge systems can be realized in a simple, fast and effective way and is therefore a benefit to the whole network , as well as a relief to sewage treatment plants.

In principle the storm water retention consist of a gully, the actual storage and a control chamber, which limits the inflow. Furthermore an overflow option has to be planned, which prevents an overload of the storm water retention and can drain the rain water into a dry well without any damage.
The ATV worksheet A 128 is decisive for measuring and designing rainwater drainage systems in the catchment area of water treatment plants. Storm water retentions (SK) in a rainwater / mixed water system are discharge facilities with overflow in waters. These special buildings are built in rainwater and combination sewers due to economic reasons. If the discharge systems aren’t measured and designed according to the technical policies, high dirt loads can get into the waters during rainfalls and put a heavy strain on them. The objective of mixed water treatments is the best possible reduction of total emissions from the sewer system and treatment plant. Sewer system and treatment plant are connected and have to be coordinated.
To design a storm water retention effectively and sustainably the decisive evaluation parameters have to be defined:

hna - long-time average height of rainfall
The long-time average height of rainfall is a location-dependent factor and has a considerable influence on the exonerative effect of the rainwater reservoirs. With increasing height of rainfall more mixes water gets into the waters. Details of the annual height of rainfall hna can be seen from the  German Metrological Service or similar.

Au - impermeable total area (fixed/unpaved)
The fixed or impermeable areas have to be carefully determined since they have a considerable influence on the size of the storage volume of the storm water retentions. This applies particularly during the forecast calculations for prospective construction or industrial areas. It has to be critically tested if the estimated areas are appropriate for prospective construction or  industrial areas. An area increase of more than 20% should be calculated in any case.

Qm - Combined sewage flow
The combined sewage flow Qm is the parameter who has the most influence on the volume determination of the storm water retention. It is often unnoticed that the parameter Qm has to be drawn from the sewer system calculation, not from the sewage treatment plant dimensioning. If a new sewage treatment plant is planned or an existing plant has to be renovated and extended, and therefore has to be measured with a Qm, which is to contain reserves for a longer period of time (15 – 25 years), this Qm has to be used in the dimensioning of the rainwater drainage system.

Qt24 - Middle dry weather flow
The actual water consumption figures are to be used. The sum of the dry weather flow from the sewer system usually has to correspond to the annual dry weather inflow of the sewage treatment plant. Within the planning the consumption figures have to correspond to the sewage treatment plant inflow.


Storm water retention - Lifted Pipes at construction site
Lifted Pipes at construction site
Storm water retention - Jointing pipes at construction site
Jointing pipes at construction site
Storm water retention - Retention pipes onsoil
Retention pipes onsoil

By calculating the crucial parameters the required buffer volume results, from which the individual assemblies can be measured and constructed. Under consideration of the local conditions the storm water retentioh from PE-HD can be manufactured custom-fit, whereby the maximum possible execution is chosen instead of the required execution due to reasons of sustainability. The costs of an immediate volume increase are in no commensurate to extensions works which have to be carried out 25 years later.
The most important formula is QZ ≤ QA + QÜ, to exclude a collapse of the restraint system.
The version of the storm water retention always conforms to the local requirements and installation conditions:

  • Type of restraint (above, middle or on the ground)
  • Type of restraint of dirt loads
  • Type of throttling
  • Type of overflow 

The thermoplastic material PE-HD has established itself as material for big volume storage sewer systems since multiple constructive and creative possibilities can be combined with optimum workability, long operating life and tightness of welded systems. The “dissolved” cross section which acts raw material saving, as well as the almost unlimited recyclability, even after decades of installation, complement the excellent features.

Steffen Lampe
Henze GmbH

Unique storm water solution

Unique storm water solution

Our English pipe producer Polypipe Civils in Loughborough, UK has provided a stormwater attenuation solution for a luxury residential development in the heart of the idyllic Bedfordshire countryside in eastern England.

Storm Water solution - Construction siteStorm Water solution - Construction site

Renowned developers, Taylor Wimpey, called upon Polypipe to provide an engineered drainage solution, designed to work with a sloping gradient found on site. Set in the countryside town of Houghton Regis, the Regent’s Place large-scale residential development comprises of a mix of 180 two, three and four bedroom houses nestled in a tranquil area that offers stunning views of the landscape. The landscape surrounding the Regent’s Place development features a large public open space with limited footprint for drainage design and sloping gradients. Taking on the challenge, Polypipe worked closely with Taylor Wimpey and Consultant Engineers JPP Consulting, to design a KRAH storm water solution, incorporating staggered legs to take requirements and adopted elements laid out under Section 104 agreement for approving site conditions into account that also met site water company, Anglian Water. 

Weiterlesen ...

Retirement yes, but not retired

Retirement yes, but not retired

Wolfgang SchneiderWolfgang Schneider

For 42 years he has been loyal to the company Krah. Now the passionate design engineer Wolfgang Schneider has gone into retirement. We interviewed him about his time at the Krah company.

Clear brew, a thundering Corvette and a “Mahlzeit” (German salutation for every day situations; literally translated “meal”) any time of day. If you mention these words every employee of Krah knows we’re talking about Wolfgang. For the past 4 dcades there has always been a loud roaring when Wolfgang drove onto the car park of Krah. One of his passions are cars, preferably old and special…or especially loud.

However,since February it has been more silent in front of the company building. On January 31st at 5 p.m. Wolfgang clicked “shut down” for the last time ever on his computer. A last soup from the automat in the kitchen, a last chat with colleagues and Wolfgang ends 42 years of working at Krah.

“I’m feeling good”, he says while walking over the car park which he has crossed thousands of times. “I’m looking forward to what comes next.”
He was very delighted about the farewell party which had been organized by his colleagues, with lots of presents some days before. “A personal highlight was a treasure chest from aluminium, made in the tool manufacture, with brass inserts to slide it open. Engraved were some figures which represented my 42 years at Krah. When I opened the chest there was a Krugerrand anniversary edition from 2017 from fine gold, a troy ounce. That was a successful surprise for my goodbye into retirement.“

Wolfgang Schneider and his CorvetteWolfgang Schneider and his Corvette

Wolfgang Schneider is a primary rock of Krah. When Karl-Heinz Krah wanted to get him for his company “Werkzeug-&Vorrichtungsbau” in 1975 Wolfgang didn’t hesitate and accepted a job as tool manufacturer.

“A decision I have never regretted”, says 63-year-old Wolfgang. “Since I can think I liked to build things and felt gravitated to technical things. In my childhood I had always wished for an electric motor.” No wonder he describes the tasks in the company more as ‘hobby’ than work.

Karl-Heinz Krah spotted this excitement for technical things and offered him a job as design engineer only a few years later. Initially he was responsible for drawing Bihler tools. His tasks changed when Krah pursued increasingly to special machine construction and finally sold the complete Bihler area.
A highlight in his career was the decisive contribution to the development of the first gravity pipe machine in 2003/2004.

Back then there was lots to fiddle. For a tinkerer like him this was a great challenge.

He described his work as “goal-oriented”. “When the things you constructed worked in the end you were happy”, says Wolfgang. “As design engineer you work for goals, not tasks.” These results are known to many Krah customers all over the world. However, Wolfgang himself is only known by very few customers. His “territory” was always the engineering office in the Westerwald. According to Wolfgang he feels way more comfortable in his office with drawing board and measurement chart than being on a business trip abroad. Still today he remembers one of the few business trips with beads of sweat on his forehead. He had almost missed his flight back then. “I almost got stuck in Russia. That was nothing for me”.  He always felt very homey at Krah. “Otherwise I wouldn’t have stayed for that long. I turned my hobby into a career. A great time!”, so Wolfgang.

Wolfgang likes to fiddle on his audio system or watch one of his many films - especially with a bottle of local beer.From now on it will be even cosier in the home theatre. Wolfgang likes to fiddle on his audio system or watch one of his many films - especially with a bottle of local beer.

He now is one of almost 21 Mio. pensioners in Germany. But he surely isn’t afraid of boredom. His answer to the question what he will miss most he smiles and says “Actually nothing. I have worked for 47.5 years now and have never been ill for a long time. I now have more time for my other hobbies.” He will continue crafting and building, especially on his home theatre audio system. But what he is most looking forward to are long trips with his Corvette and meetings with other car-fans. And if he’ll drive past KRAH during one of his tours, he will be happy to stop by and have a chat with his old colleagues.