(41u) Determining Adequate Length of Stainless Steel Piping Downstream of LNG Vaporizers

The piping that is typically used in LNG plants is a API 5L line pipe with a specified yield and toughness. In certain failure modes, there is the potential for embrittlement on carbon steel outlet piping out of vaporizers resulting in LNG or cold natural gas release to atmosphere with potential for ignition. To avoid a process safety incident from cold gas or LNG reaching carbon steel pipe, questions arose on determining what the adequate length of stainless steel pipe should be installed on outlet of vaporizer. Therefore, National Grid's SHE Process Safety Department developed a simplified model to assist with estimating approximate minimum length of stainless steel pipe on outlet of vaporizer as an inherently safer design.