1. Preface

One of the most used arguments for plastic pipe systems is the flexibility and durability. If a question appears about earthquake fitness, the plastic pipe industry normally replies by showing damage-statistics. And indeed, the statistic results are very convincing, especially with damage statistics of rigid pipe systems. In the last editions of our IMPROFIL magazine we published many reports regarding earthquakes (mainly from our friends in Japan)- but a practical orientated dynamic test of a complete plastic pipe system with all aspects of different jointing methods, fittings and constructions has never been done before.

Picture 1: Seismic regionalization of Russian Federation

Thanks to the initiative of Krah Pipes Estonia, the well-known Russian JSC Research Center of Construction in Moscow has performed an extensive test program to investigate the earthquake fitness of the full Krah Pipe System with seismic intensity of 7-9 magnitudes. For the complete technical report please contact the management of Krah Pipes Germany directly (email: Diese E-Mail-Adresse ist vor Spambots geschützt! Zur Anzeige muss JavaScript eingeschaltet sein!).
Below please find the summarized technical report with the original title:

“Conduction of dynamic tests of conduits system including pipes, fittings, containers, wells, and pump stations of trade mark “KRAH PIPES” with assessment of the opportunity of their application in the regions of Russian Federation with seismic intensity 7-9 magnitudes”.

2. Introduction

The technical report is using the results of experimental researches of polyethylene conduit elements of the trade mark “KRAH PIPES”, designed for outdoor sewerage, disposal of waste water and ventilation. The tests were conducted on the stand which was specially designed by JSC Research Center of Construction, Research Institute of Building Constructions. The stand is a pendulum-type platform vibrator.

What does it means and why should a pipe fulfil the requirements?
Today the requirements for a sustainable pipe system have changed, not always the cheapest solution is the best for a country. More and more designers and engineers dare to search for the technically best product for a project, at very reasonable costs. Also the cost aspect changed from single costs to the „lifetime cost“– from cradle to crave, including all.

So, which support for a designer or a quality control department does the so called flexibility test or flattening test mean? How is the test-procedure and how should the result be valued? In several international and national standards like EN13476, DIN16961, ISO 21138 or the ASTM F-894 a link to these tests is given – but why?

Basically the test will check how flexible a pipe can be, without having any irreversible damages on the pipe. This pipe property will give safety to the designers against overloading of the pipe or ground-movements occurred by earthquakes or unexpected soil settlement.

The standards for the test: The flexibility test is ruled in ISO 13968 and the flattening test is ruled in ASTM F894 8.6.

Picture 1: Deflection at 30%

The final test of the newest pipe production line before shipping

At least once or twice per year interested companies are invited to attend the final test run or the „first days“ of a new production line KR800-MAX for a Krah-Pipes production at the facility of the machine producer (KAT -Krah Advanced Technology  GmbH) in Schutzbach, Germany.

Picture 1: Some of our team with customers in front of the machine

This time the newest KR800-MAX is tested according to a very specific testing procedure to guarantee a quick and error free installation at the customer´s site. Several potential new customers from all over the world took the unique opportunity to enjoy the high performance of Krah-Pipe Production machines and also to take a company tour – so they can pay a visit in the RnD Department, Software developing department (WIN-KDR, MICKEY, PONTIS and all other APPs are developed here), tool making, construction, installation and also to the very impressive „mandrel“-production, where black-smiths are working hard with steel to produce giant mandrels up to DN/ID 5000 mm.

The machine presented will be shipped and installed for a customer in the Middle East where it will produce pipes successfully for a lot of pending huge projects.

This test procedure is the same for every production line, before being packed and leaving our facility. The test are mainly done with the extrusion line, because many other parts are already shipped in partial shipments before. It is the first time in the machine life a pipe will be produced. The heart of the extrusion line is a Kraus-Maffei single screw extruder 125x36D. This extruder is the best choice for this kind of production – low RPM (revolutions per minute) and a high output with perfect plastification.

Mohammed Al Hashani is the Vice President, Krah Middle East based in Kuwait. In addition, he is the Managing Director of United Gulf Pipe Manufacturing Co LLC (UGPM), which is based in the Sultanate of Oman. Key products include HDPE pipes, fabricated items such as Manholes, House Connections etc and other accessories. UGPM, under his able leadership, has achieved the following quality certifications: ISO 9001, ISO 14001, ISO 18001 related to Quality, Environment and Health & Safety.

In the interview, he informed us that he works hand in hand with the three C’s: Client, Consultant, Contractor; utilizing complex calculation techniques to arrive at a customized product that meets specific and definite requirements. Products developed are highly cost effective, with a long life, meeting environmental concerns, keeping low maintenance costs, producing homogenous product using specializing welding techniques for secure jointing, for quick and easy installation without additional training or expensive equipment.

Given the nature of the products, their applications, and stringent requirements from the three C’s, the company places maximum emphasis on Quality. This is evidenced by the fact that the department head reports directly to the MD.

Picture.1: Mr. Mohammed Al Hashani