The sub tank and master tank are tanks which are placed in the outer container (Master tank) filled with thermal insulation material in a certain arrangement after several (three or more) inner containers (sub tanks) containing medium are connected in parallel. It is generally designed and constructed for large volume and pressurized storage.

Content container

The pressure vessel used to hold medium is usually vertical cylindrical leg structure.

Outer container

The outer metal shell, which contains the inner container and forms a circular insulation sandwich with the inner container, is usually a cylindrical flat bottom vault structure.

Content container

The design and calculation of the structure and strength of the inner container are carried out according to the relevant provisions of GB150.

Vacuum leak detection is not used in the inner container, so it is not necessary to design the external pressure stability. However, considering that the diameter of the inner container is generally large, it is necessary to ensure the rigidity in the production and transportation engineering, so the inner container still needs to be set with reinforcing rings, and the spacing between the reinforcing rings is 2m ~ 3M.

The inner container should be equipped with anti vortex device and diffusion plate; Stiffeners shall be set at the legs of the lower head.

The legs of the inner container must be designed with thermal insulation, and the thickness of the epoxy glass cloth plate shall not be less than 150 mm. In order to ensure the static evaporation rate of the secondary and primary tanks and the piping space of the sandwich pipe, the height of the legs should be high enough (the height of the lower head of the inner container from the ground should not be less than 1500mm).

The short circuit of cooling capacity caused by cold bridge should be avoided, and the connecting bolt of outrigger should be equipped with insulation gasket. Through calculation, the temperature of the bottom plate of the outer vessel should not be lower than the minimum temperature that the bottom plate material of the outer vessel can use.

The aseismic design and calculation of the inner container shall be carried out in accordance with sh3048 "aseismic design and calculation of petrochemical steel equipment". The calculation process does not consider the influence of the pipe connection between the inner vessels and the surrounding insulation materials.

Outer container

The design and calculation of the structure, strength and external pressure stability of the outer container are carried out according to the relevant provisions of SY / t0608.

The connection between cryogenic pipeline and outer vessel wall adopts the structure of vacuum pipe and bellows.

configuration parameter

Volume: 300 ~ 3000m ³ Pressure: 0.3 ~ 1.6Mpa

Insulation method: pearlite accumulation insulation

Number of sub tanks: 3, 4, 7, 10, 12

Design、manufacture and acceptance criteria

TSG R0004-2009 Supervision Regulation on safety technology of stationary pressure vessel volume: 300 ~ 3000m ³ GB 150-1998 steel pressure vessels

Gb24511-2009 stainless steel plates and strips for pressure equipment

GB713-2008 steel plates for boilers and pressure vessels

GB / T14976-2002 seamless stainless steel tubes for fluid transport

Gb22724-2008 design of liquefied natural gas equipment and installation onshore installation

Code for design of arson in petroleum and natural gas engineering (GB 50183-2004)

Code for design of automatic sprinkler system (GB 50084-2001)

JB4708-2000 welding procedure qualification for steel pressure vessels

JB / t4709-2000 welding specification for steel pressure vessels

JB / T4730-2005 nondestructive testing of pressure equipment

SY / t0608-2006 design and construction of large welded low pressure storage tank

Sh3408-1999 code for seismic design of steel equipment for petrochemical industry

Specification sheet