LNG Storage Tank Design

Why are terminal headers safety-critical components of LNG vessels and terminals?
 

Pumps mounted aboard the cryogenic containment require electricity for control, instrumentation and power. The penetration from atmosphere into the cryogenic liquid is accomplished using specially designed electrical feedthroughs, also called terminal headers. Gas pressure and a temperature of -162°C place incredibly high demands on the pumps and their electrical terminal header assemblies.

Terminal headers have two key functions:
  • They must safely and reliably provide electricity and data to submerged pumps, turbine expanders and compressors
  • At the same time, they have to maintain the pressure boundary integrity of the containment.

Even in case of an accident, the sealing of the electrical connections must remain absolutely leak tight. Yet this is a potential weak point: while other feedthroughs that use epoxy or ceramic sealing materials have technological disadvantages, that could result in leakage and electrical malfunction, SCHOTT Eternaloc® terminal headers, provide the safest, most proven solution available in the market.

Find out more about the advantages of Eternaloc® Terminal Headers >

Consequences of terminal header failure can be severe

In 1979, an accident took place at the Cove Point terminal when liquefied natural gas leaked through an inadequately tightened electrical penetration seal on an LNG pump. The LNG vaporized, and led to an explosion that killed one plant employee and caused millions of dollars in damages.*
While this was an incident caused by a specific set of circumstances, it nevertheless demonstrates, that the reliability of all safety-related components – even the small ones – is crucial, for the consequences of failure could be disastrous.

 

*Source: CH-IV International: Safety History of International LNG Operations, Rev. 12 February 2012