به نام خدا introduction to storage tank MD DEPARTMENT Heidary.firstname.lastname@example.org
Table of content • Introduction • Applicable code • Parts of AST • Types of AST • Construction • Typical damages of AST • Cryogenic storage tank
Introduction • Storage tanks are a familiar part of our industrial landscape. They are used to store a multitude of different products and come in a range of sizes, from small to truly gigantic. • The ability to store large quantities of liquid and gaseous products was an essential element in the development of a number of industries. • More recently the liquid natural gas (LNG) trade, accounting for the bringing to markets of some 20% of the world’s natural gas, would not be possible without the development of large scale cryogenic storage units at both export and import terminals.
PARTS OF TANK • Bottom • Shell • Roof • Annular plate • Wind girder • Stairway • Flash type-clean out fitting • Rafter • Girder • Water spray sys.
Types of above ground steel storage tank • Foundation construction • Shape of the bottom • Type of the foundation construction • Double bottom • Material • Detection • Fixed roof • shape • Supporting • Floating roof • position • construction
Types of steel tank (foundation) • Foundation construction • Shape of the bottom cone up cone down flat with slope flat without slop
Types of steel tank (foundation) • Foundation construction • Type of the foundation construction • earth foundations without a ringwall • reinforced concrete ring wall foundation • reinforced concrete slab
Types of steel tank (bottom) • Material ( steel, polymer) • Detection • passive system • continuously activated vacuum system
Types of steel tank (fixed roof) • Self-supporting roof • cone roof - they are economical when the volumes are up to 2 000 m3 • dome roof - they are economical when the volumes are bigger than 2 000 m3. Steel dome roof could be applied when the volumes are up to 70 000 m3 ( diameter D < 65 m ). • Supported roof • cone roof – they can be applied in all existing volumes of the tanks; • hanging roof - they are still experimental.
Types of steel tank (floating roof) They are applied when store volatile products and/or the tanks themselves have big volumes • According to their position:- external floating roof- internal floating roof • According to their construction:- single deck floating roof;- double deck floating roof.
FRANGIBLE roof A Frangible roof is a roof to shell joint or junction that is weaker than the rest of the tank and will preferentially fail if the tank is over pressurized.
Shell CONSTRUCTION • rolls method • sheet by sheet (classical) method • lifting method • Tank Jacking
TYPICAL DAMAGES OF ABOVEGROUND STEEL TANKS Settlement of the tank
TYPICAL DAMAGES OF ABOVEGROUND STEEL TANKS elephant’s foot buckling
TYPICAL DAMAGES OF ABOVEGROUND STEEL TANKS floating roof damage
TYPICAL DAMAGES OF ABOVEGROUND STEEL TANKS Collapse under vacuum
GRYOGENIC STORAGE TANK • TYPES OF STORAGE • PRESSURIZED STORAGE • SEMI-REFRIGERATED STORAGE • ATMOSPHERIC PRESSURE STORAGE
LIQUFIED GASES BUTANE -0.5 BUTADIENE -4.5 AMMONIA -33 PROPANE -42 PROPYLENE -47 ETHANE -88 ETHYLENE -103 METHANE -161 LNG -162 NITROGEN -195
special parts in a cryogenic TANK • Expansion bellow • Anchor strap • Suspended deck • Cool down nozzle • In tank pump • Insulation • Base heating system • LTD measurement
Types of cryogenic tank • •Containment addresses the question: • What if the tank leaks? • SINGLE CONTAINMENT • DOUBLE CONTAINMENT • FULL CONTAINMENT • MEMBRANE TANK
⑥ ⑤ ⑦ ① ⑧ ② ④ ③ ⑨ 1 primary container (steel) 6 roof (steel) 2 bottom insulation 7 loose fill insulation 3 foundation 8 outer steel shell (not capable of containing liquid) 4 foundation heating system 9 bund wall 5 suspended roof (insulated) SINGLE CONTAINMENT
⑦ ⑥ ⑩ ⑧ ⑨ ① ② ③ ⑤ ④ 1 primary container (steel) 6 suspended roof (insulated) 2 secondary container (steel or concrete) 7 roof (steel) 3 bottom insulation 8 loose fill insulation 4 foundation 9 outer shell (not capable of containing liquid) 5 foundation heating system 10 cover (rain shield) DOUBLE CONTAINMENT
FULL CONTAINMENT 1 primary container (steel) 5 suspended roof (insulated) 2 secondary container (steel) 6 roof (steel) 2 bottom insulation 7 loose fill insulation 3 foundation 8 concrete roof 4 foundation heating system 9 pre-stressed concrete outer tank (secondary container)
Ammonia tank • What makes ammonia storage special? • Flammability • Toxicity • Latent heat • Electrical conductivity • Stress corrosion cracking • The truly lethal nature of the gas means that special measures are required for the design, • construction and especially the operation of storage facilities.
Concrete storage tank Prestressed concrete has become the most commonly used Material for the outer containers of full containment low temperature tanks.