The careful stress analysis for the earthquake and wind.
The strength of tank for the earthquake and wind shall be carefully analyzed by computer and also the tank shall be manufactured enough to endure all the stress.
All the elements, floating roof and seal device, had been standardized on the basis of plentiful experience and technology. The standardized tank will be satisfied in strength and maintenance.
The thorough control of the welding we will use high-tension steel plate and reliable welding procedure control for large sized tank.
The shop and field inspection systems are established and the strict inspection will make more reliable tank manufacturing.
Single Deck Type
A single deck type floating roof has an annular pontoon around the edge and a deck of single thickness in the center as seen in the diagram. The annular pontoon is divided into several chambers by radial bulkheads.
The upper surface of the pontoon is slanted down toward the center for drainage purposes and the lower surface of the pontoon is inclined upward to the center of roof in order to accumulate vapor in the single deck part.
The ratio of pontoon area to the total area varies according to the size of the tank, storing product and the accessories.
Double Deck Type
A double-deck type floating roof has two complete decks covering the entire liquid surface. The roof is consisted of a portion divided by the ring and radial bulkheads into several compartments and a portion called the flexible bay.
The flexible bay can be inflated according to filling operations or as rainwater accumulates on the top deck of the roof sloping downward.
The bottom deck slopes upward toward the center so that accumulated vapor is trapped at the center of the roof.
Covered Floating Roof Tank
The covered floating roof tank features affixed roof in addition to the floating roof . Due to the simplicity in design and high strength materials used in manufacture, many years of trouble-free service can be expected.
By the utilization of affixed roof, the floating roof is well protected from the elements, thereby, drastically reducing maintenance costs and preventing evaporation loss. In addition, hardly any accessories are required, permitting the floating roof to be used at lower levels which is almost impossible with conventional floating roof tanks. Even if vapor accumulates, it will not exceed the explosion point since the space above the floating roof is well ventilated.