The Society for Gas as Marine Fuel (SGMF) has issued a formal safety notice to address concerns about leakages during LNG bunkering operations using certain types of coupling systems.
According to the note, SGMF Secretariat has received several reports of leakages from dry-disconnect/connect couplings – also known as quick connect/disconnect systems – in service during LNG bunkering operations for 6” and 8” nominal diameter bunkering lines.
Differential movement between supply and receiving bunkering equipment is understood to be the cause of the leakages at the dry-disconnect/connect coupling sealing face/surface. SGMF says that it’s not clear that any design loads are being exceeded while the movement is occurring, but it is causing the coupling to leak.
The safety notice urges operators to take care to ensure couplings are not overloaded during the bunkering process. It is recommended that, for coupling sizes 6” and above, the equipment is fully supported throughout the transfer operation.
“This might be achieved by using additional support structure around the coupling nozzle and cryogenic hose, however each party should evaluate the best solution depending on their applications and equipment, e.g. straps or clamps might be used instead,” the SGMF said.
So far, all reported leakages have been detected and dealt with safely.