Liquified Natural Gas (LNG) and BLEVE explosions

Although in its liquid state LNG is not explosive and cannot ignite, if vaporised and mixed with air it becomes combustible. This can occur if LNG were to leak from a faulty flange joint in a pipeline during movements between processing, storage, transportation and regasification. The LNG would vaporise rapidly at which point if it reaches a source of ignition would catch fire.

BLEVE - Boiling liquid expanding vapor explosion

A Boiling liquid expanding vapor explosion (BLEVE) is an explosion caused by the rupture of a vessel containing a pressurized liquid that has reached a temperature above its boiling point.[1][2] Because the boiling point of a liquid rises with pressure, the contents of the pressurized vessel can remain a liquid as long as the vessel is intact. If the vessel's integrity is compromised, the loss of pressure drops the boiling point, which can cause the liquid to rapidly convert to a gas expanding rapidly. If the gas is combustible, as in the case with hydrocarbons and alcohols, further damage can be caused by the ensuing fire.

Many such incidents have occurred, with catastrophic results.

How can I mitigate risk?

Liquified Natural Gas (LNG) projects have numerous applications for safety shields, whether it be the cryogenic LNG process itself or one of the many other chemicals used. Shields are commonly used as one way to mitigate the risk of a BLEVE incident.

The flange joints along the LNG lines themselves need to be shielded to prevent a jet release which would otherwise permit LNG vapour to mix with air and become combustible. This can be done by installing spray safety shields on flange joints stopping the formation of a mist/vapour cloud.

Flangeguards has successfully delivered many thousands of safety shields for LNG applications on projects all around the world. Installation of Sureband Steel spray safety shield to the flanges of pipelines at LNG processing plants and storage facilities control LNG spray out, preventing risk of fire and explosion.

  • Sureband Steel is manufactured from 316 Stainless Steel and works effectively at high pressure and wide temperature ranges.
  • Sureband Steel features Pressure Diffusion Technology to control any escape of LNG from a faulty flange preventing vaporisation.
  • Sureband Steel has a Quick Fit connection and fits multiple flange sizes preventing fitting errors.
  • Sureband Steel is manufactured by Flangeguards Limited to ISO9001:2015.

For LNG itself, we recommend the following shield type (Sureband Steel);-

For other process chemicals, we recommend the following shield type (Sureband Clear);-

 
Recommended

316 STEEL shield with Pressure Diffusion Technology (PDT) incorporating multi-layered steel mesh. Simple design and quick-connection latch

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Recommended

All PTFE shield with Pressure Diffusion Technology (PDT) incorporating multi-layered PTFE mesh. No pull-cords, quick connection. Litmus indicator patch included

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