Breathing Safely at Sea: Understanding Primary and Secondary Venting Systems on Tankers
Why Tankers Need Venting Systems Modern oil and chemical tankers are designed to transport vast quantities of liquid cargo safely across oceans. While these cargoes appear stable inside their tanks, they constantly generate vapours due to changes in temperature, pressure, loading, discharge, and natural evaporation. Without a properly functioning venting system, pressure inside cargo tanks can rise to dangerous levels or create a vacuum during cargo discharge. Either condition can damage the cargo tank structure, compromise cargo quality, and create significant safety hazards. Cargo tank venting systems are therefore an essential part of every tanker's design. They maintain safe pressure limits while preventing the release of excessive hydrocarbon vapours into the atmosphere. The venting arrangement also minimizes the risk of fire and explosion by controlling how gase...