This first instalment of a multipart deep dive examines the low‑pressure (LD) compressor — the pivotal system that manages boil‑off gas (BOG) on liquefied natural gas carriers. It provides a general overview of how BOG, formed as cargo warms from −160 °C, is converted from a safety risk into usable fuel or recondenser feed, and how the LD compressor must reliably deliver pressures from near atmospheric up to double‑digit bar levels for engines, requefaction plants and gas combustion units. The episode covers core technical challenges (liquid carry‑over, thermal shock, surge), typical machine selections (oil‑free reciprocating, dry screw, and the role of centrifugal boosters), and the essential role of variable‑speed drives, anti‑surge controls and automated safety trips. Practical retrofit strategies and the prospects for predictive, anticipatory control are introduced. Essential listening for engineers, operators and decision‑makers seeking a concise, authoritative overview.

• LD compressor
• boil‑off gas
• LNG carriers
• low‑pressure compressor
• requefaction
• gas combustion unit (GCU)
• oil‑free reciprocating compressor
• dry screw compressor
• anti‑surge control
• variable‑speed drive (VSD)
• mist separator
• IGC code compliance
• 
  

Produced using NoteBookLM with proprietary in‑house articles.

You can watch this episode on YouTube.