LPG carrier

An LPG carrier transports liquefied petroleum gases — primarily propane and butane — as well as petrochemical gases such as ammonia, ethylene, vinyl chloride monomer (VCM), and propylene. Vessels are classified by their cargo-handling system: fully pressurised ships carry cargo at ambient temperature in cylindrical pressure vessels (up to 17.5 bar); semi-refrigerated ships use a combination of partial cooling and moderate pressure; and fully refrigerated ships carry cargo at atmospheric pressure and low temperature (propane at −42 °C, ammonia at −33 °C). Size ranges from small coastal pressurised vessels of a few hundred cubic metres to Very Large Gas Carriers (VLGCs) of 80 000 m³ or more serving intercontinental LPG trades. Ethylene carriers — handling cargo at −104 °C — require specialised Type C independent tanks and are classed separately under the IGC Code Appendix provisions. All LPG carriers must comply with the IGC Code (SOLAS Chapter VII), which sets requirements for tank design, vapour detection, fire fighting systems, and personnel safety. MARPOL Annex I restrictions may apply when vessels carry low-flashpoint petrochemicals. The Cargo Record Book and regular surveys are administered under flag State and classification society oversight. For a full size and trade classification see the /reference/ship-types page.