IMO C – Tank
Torgy LNG delivers type C-Tank for projects worldwide, represented in Europe and Asia, secure design and quality at a high level for a competitive cost.
The C-Tank type is the most common tank technology for LNG fuel containment, typically used as a fuel tank for cargo vessels. The construction is similar to a pressure vessel, based on the cylindrical design for optimal material usage vs. internal pressure, with a maximum design pressure of 10 bar for marine applications.
Like other LNG tanks, the C-type needs insulation to keep the content cold and minimize LNG boil-off. There are two types of insulation used, double shell with vacuum and insulation in annular space and single shell with spray insulation on the outer layer. Double shell is primarily used for smaller sizes and up to typically 1.000 m3 and spray insulated types for tanks above those sizes. For Single Shell C-tank, the surrounding area has to be classified as Ex Zone 1, if the tank penetrations on top (dome) are not capsuled with a Tank Connection Space (TCS). For Double Shell tank, TCS is a necessity, and covers all tank penetrations and belonging equipment. Most commonly positioned on the dished end of the tank. Indoor installation can be protected with an air-lock system, and outside installation (on deck) a single gas tight door is sufficient to limit the hazardous area.
Allowed pressure build-up in C-Tanks is beneficial for LNG containment, and holding time for storage increases related to other tank concepts. The pressurized boil-off gas can also be used directly by consumers like boilers or as fuel gas for low-pressure engines.