A gas carrier built for the transportation of petroleum gases in bulk. LPG tankers often can carry some other gases such as ammonia, propylene and vinyl chloride. The cargo list for a LPG carrier specifies what type of cargoes the vessel shall be designed for. Practically all LPG carriers can handle LPG, ammonia, propylene and VCM. For larger gas carriers there is a tendency that some of the cargoes are removed from the cargo list. Wärtsilä Oil & Gas System has a significant market share in the delivery of cargo handling system for both LPG and LEG vessels.
Considering the temperature and the pressure needed, the LPG carriers can be divided into three categories: full pressure type, semi-refrigerated type and fully-refrigerated type. Small size ships (less than 4000m3 of cargo capacity) are usually the full pressur type. The semi-refrigerated technique is used for the cargo spaces around 7500m3, and fully-refrigerated technique is intended for the cargo spaces between 10,000m3 and 100,000m3. See also PTARMIGAN.
Further reading: ABS Guide for “Liquefied Petroleum Gas Carriers with Type-A Independent Tanks” (2006), can be downloaded from www.eagle.org