Marine & TransferIntermediate

LNG Vapor Return Systems

Study how vapor is returned between ship and shore during LNG transfer to manage displacement vapor and pressure.

System context

Ship-shore vapor balance

Technical topic pages show the knowledge scope behind LNG University learning. Course, assessment and credential availability depends on the applicable program.

Relevant roles

Marine operators · Jetty operators · Control-room personnel · Process engineers

Prerequisites

LNG loading arms · BOG management

Knowledge level

Intermediate technical coverage with system and operational context.

Learning outcomes

What this topic is intended to help you understand

Explain why vapor return is needed during transfer.
Trace typical vapor-return routing and connected equipment.
Recognize the interaction between ship pressure, shore BOG capacity and transfer rate.

Technical scope

Equipment, concepts and terminology

Vapor return arms
Vapor headers
Ship-shore pressure balance
BOG compressors
Isolation valves
ESD interfaces

Operating context

How the topic connects to plant operation

Pre-transfer line-up
Pressure monitoring
Transfer-rate coordination
Response to vapor-return limitations

Safeguards and controls

Protection and risk-control context

Ship-shore ESD
Pressure limits
Gas detection
Emergency release coordination

Technical learning does not replace site procedures, OEM documentation, engineering calculations, permits, supervision or facility-specific authorization.

Engineering documents

Documents commonly connected to this subject

Jetty P&ID
Transfer procedure
ESD cause & effect chart
Marine terminal manual