Australia Pacific LNG successfully completed the hydro and pneumatic testing on its second LNG storage tank, a first for Curtis Island.
Australia Pacific LNG’s two 160,000m3 storage tanks, which are designed to store the chilled LNG prior to being shipped, took a total of two months to test and complete.
Page Maxson, Australia Pacific LNG CEO, explained, “What sets the Australia Pacific LNG job apart is that the testing on both tanks was done back to back, and that in itself is a world-class achievement.”
“We also undertook hydro and pneumatic testing simultaneously; a process that is usually conducted separately and has therefore saved us time,” he said.
LNG tanks are huge structures, with each one close to the size of a football field and over 30 metres high. Testing takes up to 26 days per tank and requires filling the tanks with water to test its integrity, quality and stability. Pneumatic testing is carried out to confirm the tank is ‘gas tight’, and to test the pressure and vacuum release valves.
“LNG is lighter than water, so by filling each tank with water, we can be sure that the tanks foundation will be able to support the weight,” he said.
Each tank is designed to keep the LNG chilled to -161°C, and this is done by insulated walls up to 2 metres thick. Construction of the tanks was undertaken by Bechtel and CB&I.
When both LNG trains are in operation in 2016, it will take approximately three days to fill each 160,000m3 tank. Australia Pacific LNG expects a ship to arrive every 3 days, taking approximately 12-14 hours to load each ship with LNG.
The completion of testing of the LNG tanks plays a critical role in the delivery of first LNG exports in mid 2015, with gas from the Surat and Bowen basins delivered to Curtis Island through the pipeline system where it will be liquefied and shipped to Asia.
Press Release, August 29, 2014; Image: APLNG