Section 2 Design of Loading and Offloading Systems

201. General

The design of the loading and offloading system is to consider all modes of operating, testing, sur- vival and accidental events. The loading and offloading system is to be analyzed to determine its response to the design events. Each individual component is to be examined for its strength and suitability for the service conditions.

202. Loading system and offloading system

1. Loading arm

(1) The main requirements to a marine loading arm are as follows :

(A) The fluid conduit should not carry any structural loads. The loading arm is to be con- structed by a pipe system fully supported by a supporting structure independently.

(B) The supporting structure shall not be exposed to cryogenic temperature.

(C) The loading arm shall be free to move within the designated envelope, i.e. the connection head shall be free to move with 6° of freedom.

(D) The loading arm shall be fully balanced in retracted position when unloading.

(E) The loading arm shall be equipped with an ERC(Emergency Release Coupling) allowing a quick release with a minimum spill of LNG.

(F) The emergency shut down logic for the loading arms shall have two levels. The first level

is stops flow and prepares for disconnection and second level is releasing the coupling.

(G) The detailed requirements for loading arms may be accordance with EN1474-1.

(2) The structural design of the loading arm support should consider the following loads.

(A) Static loads : weights of unit, ice LNG and etc.

(B) Wind loads

(C) Fatigue reflecting the operation

2. Cryogenic Flexible Hose

In cases where floating hoses are used to transfer the LNG from the carrier to unit, such floating hoses are to comply with the following requirements.

(1) Breakaway couplings are to be provided with shut off valves in each Cryogenic Flexible Hose string in order to minimize the hazard of LNG in emergency situations.

(2) Cryogenic Flexible Hoses are to comply with recognized standard(OCIMF, API, MARPOL, etc.),

and to hold appropriate certificates for necessary tests and inspections.

(3) The construction of connections between hoses and the unit(bolting, gaskets, etc.) are to be suit- able for their intended service.

(4) The detailed requirements for loading arms may be accordance with EN1474-2.