Improving LNG Plant Piping: Or How LNG Plants Are Improving Piping

Abstract An LNG plant is essentially a variety of static and rotating mechanical equipment interconnected by piping. LNG plants contain a significant amount of piping that is characterised by one or more of the following: large diameter, high design pressure, cryogenic temperatures, stainless steel, high velocity gas flow, large diameter-to-thickness (D/t) ratios and load cases not explicitly addressed by design codes. One of the most commonly used piping codes in LNG plant construction, ASME B31.3, has its basis in petroleum refining. However, recent editions of ASME B31.3 (as well as other industry standards) include updates addressing issues which are of particular relevance to LNG plant piping. Aside from the benefits to LNG piping, these improvements will benefit all piping falling under the ASME B31.3 code. This paper will discuss some of the engineering challenges inherent to LNG plant piping. Recent changes to relevant codes and standards will be highlighted. The focus will be on ensuring mechanical integrity rather than the process side.