Trenchless pipe rehabilitation project at Heiligenkreuz, Austria – Close Fit all round

The town of Heiligenkreuz in southern Burgenland, Austria, decided to exploit this advantage by awarding the contract to renew a decayed drinking water pipeline to pipe rehabilitation specialist Rabmer, a member of SPR (SEKISUI Pipe Rehabilitation) Europe.

 

The innovative r.tec® Close Fit method has been effectively employed in the pressure pipe sector, e.g. drinking water, gas and gravity pipelines, for over two decades. Ongoing optimisation and further development of the system have resulted in the new r.tec® Close Fit pipe, which has been successfully marketed since 2008. This pipe rehabilitation technology is based on a HDPE pipe whose cross-section is deformed after extrusion by thermo-mechanical tools, reducing the diameter by approx. 25-30% to facilitate insertion into the damaged pipe. Wound on drums and drawn into the pipe by a traction limited winch, it enables installation lengths of several hundred metres to be achieved in one step. The subsequent application of hot steam and pressure restore the original round shape (memory effect) of the pipe and attach itself to the old pipe without an annular gap – thus “close fit”.

 

Every pipe rehabilitation project starts with cleaning, followed by a TV inspection of the old pipes to ensure that they are largely free of deposits. After the rehabilitation a further camera inspection takes place before the section is connected to the main pipe by mounting standard pipes and fittings to provide the customer with a new high-quality and durable pipe for future operation.

 

The Lower Lafnitztal Water Board (WVUL) commissioned Rabmer with the rehabilitation of the drinking water pipeline in the municipality of Heiligenkreuz, Austria. The major challenge of the project was the extremely short time frame allowed, in which the long installation lengths had to be rehabilitated with the r.tec® Close Fit liner. The PVC and asbestos-cement pipes to be renewed with diameters of DN 200 mm and a pressure stage of 10 bar had already signalized a call for action with a number of ruptures. In addition, road constructions were planned which would require the pipelines to be protected against further ruptures prior to the start of road works. Only two installation pits were needed for the rehabilitation, through which the Close Fit liner was drawn into the old pipe. A length of 250 m was installed in the first section and 410 m in the second section. The total pipeline of about 660 m was rehabilitated in no more than 40 hours from disconnection to reconnection with two installations. The Close Fit pipe liner was heated for almost four hours to return the newly laid pipe to its original shape to create a new, fully functional drinking water pipe.

 

The Rabmer Group has been working on trenchless pipe rehabilitation technologies for almost 25 years, acquiring enormous know-how and developing a number of innovative products. The company offers a variety of methods for inspecting, cleaning and rehabilitating pipelines and vessels of all kinds in the drinking water, gas, sewage, oil, industry and building sector.

 

“We employ a wide range of methods to offer our customers solutions for problems with leaking pipes or vessels. We have successfully rehabilitated thousands of kilometres of pipelines and are frequently called on to tackle the most difficult of projects,” reports Managing Director Mag. Ulrike Rabmer-Koller.

 

The sphere of activity of the Austrian construction company covers the whole of Austria and Eastern Europe. Today the group maintains 14 locations in ten European countries and generated revenue of € 28 million in 2011 with a workforce of 185. Rabmer has been a member of SPR Europe since December 2011.