This excerpt taken from the LNG 10-Q filed Aug 4, 2006.
2.1 LNG Storage Facilities
The LNG will be stored in two single containment insulated LNG storage tanks (the Tanks) (also designated as Tank S-104, and Tank S-105), of 160,000 cubic meters net storage capacity each. Future LNG Tank S-106 is excluded from this scope.
The Tanks will be designed and constructed so that the primary container and an earthen impoundment dike will be capable of independently containing the LNG.
The Company will let a contract directly to a specialty tank contractor (the Tank Contractor) for all necessary engineering design, procurement of materials and equipment, fabrication, delivery, erection, installation, testing and pre-commissioning of the two above ground, single containment tanks. Design and purchased components will include but not necessarily be limited to: piling and tank foundations, single containment tanks, associated equipment and structures, piping, tank insulation, instrumentation and electrical systems. The Tank Contractors work, unless specified otherwise, shall extend to its Battery Limits defined as 20 feet beyond the outside perimeter of outer tank. The sole exceptions shall be that Bechtel shall procure and provide the Tank Contractor with three in-tank pumps for each Tank, dry chemical system, LP vent stacks, and also control valves, for installation by Tank Contractor.
Each Tank will be a double walled design and will consist of a 9% nickel steel inner container; a carbon steel outer tank and a carbon steel domed roof with an insulated aluminum deck over the inner container suspended from the domed roof.
The annular space between the inner and outer tanks will be approximately 36 inches wide and will be filled with Perlite. The suspended deck will be insulated with glass wool blankets. The Tank bottoms will be insulated with cellular glass load bearing block insulation designed to support the Tank and product weight.
The inner container will be designed and constructed in accordance with the requirements of API Standard 620 Appendix Q. The Tank system will meet the requirements of NFPA 59A and 49 CFR Part 193. The inner tank will be open top, consisting of a shell and bottom. The self-supporting roof of the outer tank will contain gas and gas pressure produced by the stored product. The Tanks will be designed taking into consideration the seismic loads as well as the wind loads.
The Tank insulation system will be designed to limit the Tank Boil-Off rate to a nominal rate of no greater than 0.05% by volume per day of the Tank contents at an ambient temperature of 90°F, with the Tank full and in a steady-state condition. The nominal Tank Boil-Off rate will be documented through heat transfer calculations.
Tank instrumentation will consist of resistance temperature detectors (RTDs) for sensing the Cool Down and foundation temperatures, tank gauging system that will provide level, temperature, density and a data acquisition system. The Tanks will be protected with pressure and vacuum relief systems. For servicing of relief valves a monorail will be provided.
Roof platforms will be provided to provide sufficient working space around the pump wells and piping. A Jib Crane will be provided for the maintenance of pumps and control valves etc.
Four intank pump columns will be installed in each Tank for three operating pumps and the fourth spare for a future intank pump. An additional spare pump (shared by the 2 new tanks) will be stored in the warehouse.
Stairways and an emergency escape ladder will be provided to access the roof platforms. A stairway will be provided to the inner tank bottom.
Spill protection of the Tank roof will extend over the edge of the roof dome with a chute to grade.
Exposed portions of carbon steel surfaces of the tank shell and roof will be blasted and painted. Stainless steel, aluminum and galvanized surfaces will not be painted.
A general Tank lighting system will be provided. Emergency lighting and aircraft warning lights will also be provided. Each Tank will be provided with a tank-grounding grid.
In addition to other testing during installation of the Tanks, partial hydrostatic testing of the inner container will be performed in accordance with API 620 Appendix Q8. Hydrotest water will be discharged in accordance with Applicable Law upon completion of the tests. A pneumatic test of the outer container will be performed in accordance with API 620 Appendix Q.8.
A settlement monitoring system will be provided to measure and record inner and outer container movements during construction and hydrotest. This construction monitoring will form the basis for continued periodic monitoring once the Phase 2 Facility is in operation.
The Tanks will be equipped with continuous density monitoring instrumentation to detect stratification. Facilities will be provided to circulate the stored product so that if stratification begins to develop, the Tank contents can be thoroughly mixed within each Tank and between Tanks.