How much do you know about IGU LNG Storage and Vaporization Facilities?

Overview of IGU LNG Storage and Vaporization Facilities

• The IGU LNG Storage and Vaporization Facilities store and vaporize liquefied natural gas (LNG) for delivery into the gas distribution mains in Fairbanks.

• The sites have a gravel base and are surrounded by a chain-link security fence with a vapor barrier and security lighting.

• The principal components of the facilities include LNG storage, transfer, vaporization, odorizing, metering, pressure regulation, electrical and PLC, fire and gas detection, and emergency shutdown devices (ESD).

• The LNG storage tanks are cryogenic vessels designed to store LNG at up to -320o F at maximum design pressure, but IGU stores LNG at about -230o F at 45-55 psi.

• Each tank is two tanks, one inside the other, with an annular space filled with Perlite granular insulation or other suitable insulation and pulled to a vacuum.

• The IGU tanks are protected from overpressure by a dual safety relief valve system and have blowdown valves to manually release pressure.

• Stratification of LNG can occur in LNG storage tanks, but the ASME tanks at the IGU storage facilities have round bottoms and sides, which promote convection and constant natural stirring of the liquid, preventing stratification.

• The vaporization system uses a system of heat exchangers and gas-fired boilers looped together by a glycol system, with backup self-contained combination heaters and heat exchangers.

• The LNG transfer system consists of an impounded area with a cryogenic pump and fill manifold, with both pressure and pump transfers available at each site.

• The pressure building system automatically maintains the tank pressure to a set level using ambient vaporizers connected to the tanks and several controllers that open or close a liquid valve, which then feeds LNG into an ambient vaporizer.

• The boiloff system reduces the tank pressure by allowing the gas vapors to exit the tank through a backpressure regulator, and into the vaporizers, metering and odorant systems, and then into the distribution system.

• The facilities have fire and gas detection systems, firefighting equipment, and emergency shutdown devices that can be manually activated by operators.Security and Training Procedures at LNG Storage Facilities

• Security fencing will be placed around the perimeter of the LNG storage facility.

• The fencing will have a minimum height of 8 feet and will include two 10 ft. X 6 ft. swing gates.

• The gates will connect and lock together in the middle of the north truck lane.

• All gates will have a lock and code system for security purposes.

• The facility will have security cameras installed to monitor the perimeter.

• The security fencing will retain the vapor barrier to minimize vapor dispersion in a spill event.

• New operators must receive initial training and be trained on assigned tasks before performing them unassisted.

• New operators may perform tasks assisted by trained and qualified personnel for on-the-job training.

• Supervisors will observe or test new operators on specific tasks once they are properly trained.

• Operators will be reevaluated when new procedures are incorporated or if deemed necessary by the supervisor.

• Continuing instruction (refresher) will be conducted at intervals not to exceed two years.

• IGU must maintain all training records for all employees for their entire employment, plus one year.