Team effort post-tensions an LNG Tank

DSI USA undertook the supply and installation of the post-tensioning material for the 1 million barrel liquid natural gas tank in southern Puerto Rico. The tank is owned by Enron Corporation and was built by PDM (Pitt-Des Moines) now owned by Chicago Bridge and Iron.

The tank is 293'-0" (89.30 m) in diameter, 136'-0" (41.45 m) high, and the walls are 2'-0" (0.61 m) thick incorporating four buttresses.

The tank is a dual wall steel tank fabricated of cryogenic steel to withstand the extremely low temperatures of the liquid nitrogen required to cool the natural gas. A post-tensioned concrete impoundment wall designed to contain an explosiomn of the neutral gas in the tank surrounds the tank.

During the construction of the concrete walls, DSI provided technical guidance to the main contractor and oversaw the installation of the duct and all embedded items. After completion of the wall construction, DSI crews pre-fabricated and installed the vertical "U" tendons, then continuing on to the installation of the horizontal tendons. After successfully stressing all tendons, the entire structure was grouted.

The structure utilized consistently 19-0.6" tendons meeting the cryogenic requirements specified.

DSI used personnel from many operating units of the DSI Group around the world including the USA, Canada, Germany, Scotland, and Mexico. This project was truly an international team effort.

Construction was on a tight schedule requiring significant coordination and substantial manpower. The works were completed to the full satisfaction of the client in June 2000.

SupplyInstallationStressing GroutingTechnical assistance

Pitt-Des Moines Inc., Pittsburgh, PA, USA

Aireko Construction Corp., Ponce, Puerto Rico