Liquefaction plants

The design, location, layout, materials, equipment fabrication, construction, staff training and daily operation of liquefied natural gas plants are governed by strict national and international standards.

Plant workers receive specialised training and are well drilled in contingency planning in the unlikely event of an incident.

Security at these plants is a priority and is maintained through controlled access, safety zones, protected safe areas and constant monitoring.

Stored at low pressure

Liquefied natural gas is stored at near atmospheric, or low, pressure.

This means it is not under pressure like the gas in cylinders used for barbecues or motor vehicles.

The liquefied natural gas is stored in special double-wall tanks that have inner primary containers made from steel that can withstand extreme cold, and outer secondary concrete containers with pre-stressed concrete walls.

Cross-section of a liquefied natural gas storage tank.

The bases of liquefied natural gas tanks are made of heavily reinforced concrete and the dome-shape tank tops are made of concrete or steel.

The tanks are designed to resist extreme events including earthquakes, blasts, fires and other impacts.

Insulation surrounds the inner containers, above and below and around their sides.

The space between the inner and outer container walls contains insulation about 100cm thick to keep the gas cold.

Full containment

In the unlikely event of a failure of an inner steel wall, the outer post-tension concrete wall will retain the liquefied natural gas safely within the tank.

Modern onshore liquefied natural gas storage tanks are made with 9% nickel-steel alloys. These modern tanks have never had a major crack failure in more than 35 years of operation.

Storage and loading facilities are designed to contain leaks or spills and have fire protection systems, multiple leak and fire detectors, alarms and automatic and manual shut-down systems.

Sophisticated sensors throughout the plants can trigger an emergency shut down when unsafe conditions are detected.

The transfer system between the ship and the storage tank cannot be operated unless all cargo-related safety systems are properly functioning.