Development of internal drying technology of pipes
2010-06-01
From the beginning of the 2000’s, MOL FGSZ required for newly built gas pipe sections and process systems that after the pressure strength test they are dried from inside, up to a certified dew-point of -10°C.
Until 2007 this type of special drying equipment was not available in Hungary, drying tasks were executed with the so-called “fan” method. Yet, for drying the 54 km long DN800 gas pipeline between Pilisvörösvár-Százhalombatta built in 2007-2008 by KVV, this method would not have had the required capacity and efficiency.
Foreign companies offered drying the pipeline at a price of 1 EUR/linear metre. At this point KVV decided – after doing some calculations regarding return on investment and taking into account the expected future work opportunities – that it would purchase two drying units and a compressor producing oilfree air required for their operation. The CD780 R type drying unit and XAS 746 type compressor of the company ATLAS COPCO were chosen. Géza Németh, the director of the Technological Service Department of KVV performs the technological development, commissioning and operational processes. The essence of the technology: with the help of the compressor super dry (dew-point of -40°C) air is created in the tanks of the drying unit, and this air is then flown into the system to be dried, until the dew-point of the air leaving at the exit points does not reach the value required by the customer.
Since 2008 KVV has performed all its drying tasks with these units, and one of the units was also successfully engaged in a drying project in Slovenia in 2009 (DN150, 15 km) for the company GEOPLIN-PLINOVODI d.o.o. (Slovenian gas transmission company), as a subcontractor of the Croatian company MONTER Strojarske Montaze d.d. More over, at the Zsana gas tank extension project of E.ON Földgáz Storage Zrt. we performed the drying activities of the overground technology pipe system for the German main contractor Max Streicher GmbH. In regards to return on investment this development project was one of the most successful investments of KVV.