Dresser surge relievers selected to protect segment of river pipeline project in Libya

Oct. 15, 2009
SALT LAKE CITY, UT, Oct. 15, 2009 -- Flexflo 887 surge relievers manufactured by Dresser Inc. have been chosen to protect the newest segment of the Great Man-made River (GMR) water supply project that brings water to the citizens of Libya...
Dresser's Flexflo 887 Surge Reliever.

SALT LAKE CITY, UT, Oct. 15, 2009 -- Flexflo® 887 surge relievers manufactured by Dresser Inc., a leader in providing reliable, highly engineered products for global infrastructure projects, have been chosen to protect the newest segment of the Great Man-made River (GMR) water supply project that brings water to the citizens of Libya.

The Flexflo 887 units were selected for this project because they are the fastest acting surge relievers in the world -- able to respond within milliseconds to a potentially dangerous rise in pipeline pressure.

Listed by the Guinness Book of World Records as the world's largest underground network of pipes and aquifers, the Great Man-made River project is an enormous, long-term undertaking to supply Libya's water needs. The GMR draws water from ancient aquifers beneath the Sahara Desert in southern Libya and conveys it northward along a network of huge concrete pipes to the Mediterranean coast where the majority of Libya's 6 million citizens live and work. When it is completed at an estimated cost of $33 billion, the GMR will carry 972 million gallons (3.68 million m³) of water each day over a 2,500 mile (4,000 km) long pipeline network.

The turnkey, skid-mounted Flexflo surge relievers will be installed at the Azrair Pressure Control Station along the Ghadames-Zwara-Az Zawiyah segment of the GMR in northwestern Libya. Installation of one skid with three 10-inch units and a second skid two 4-inch units will follow in early 2010 by the pipeline contractor Al Nahr Company Ltd.

Surges in pipeline pressure are common and can be the result of unintended pump shutdowns and valve closures along the pipeline, explained Chris Jewell, Flexflo surge reliever product line engineer. Jewell compared the mass of fluid traveling through a pipeline to a locomotive pulling a heavily loaded train and traveling at speed. Neither can be stopped dead in its tracks, he said.

"In a pipeline, instantaneously stopping or changing the velocity of liquid will cause it to 'pile up' and create a pressure spike in the line. If the surge is not relieved, it can damage the pipeline and related equipment and endanger people," Jewell said. In addition, because liquids cannot be compressed, the pressure surge will travel through the liquid in the pipeline at sonic speeds -- 1,100 ft per minute. Milliseconds count, he said, because the faster a surge reliever can respond, the better it can mitigate the potential dangers of a pressure surge.

Dresser's Flexflo surge relievers feature a unique, proven design that utilizes an elastomer tube surrounded by a nitrogen "blanket" which holds the tube at a constant pressure equal to normal pipeline pressure and seals off the surge reliever. When pipeline pressure spikes, the surge causes the nitrogen to compress the tube almost instantaneously, opening the surge reliever and allowing the liquid to be channeled out of the pipeline to prevent damage to the line. Because the Flexflo 887 surge reliever has just one moving part, maintenance time and expense is minimized.

Funded by the Libyan government, construction of the GMR project began in 1984.

About Dresser Inc.
Dresser Inc. is a global leader in providing highly-engineered infrastructure products for the global energy industry. Leading brand names within the Dresser portfolio include Dresser Wayne® retail fueling systems, Waukesha® natural gas-fired engines, Masoneilan® control valves, Consolidated® pressure relief valves, and ROOTS® rotary gas meters and blowers. The company has manufacturing and customer service facilities strategically located worldwide and a sales presence in more than 100 countries. Web: www.dresser.com