Storage Tank Design Codes and Standards
We supply tanks and vessels designed, manufactured, inspected, tested and certified to the
following codes and standards:
• The Pressure Equipment Directive 97/23/EC (the PED)
• PD5500 construction category 1, 2 or 3
• ASME VIII Div. 1 (non code stamped)
• BS EN 13445 press vessel
• BS EN 12079/DNV 2.7-1 Offshore containers and associated lifting sets
• BS EN 12285-1 & -2 (horizontal storage tanks, steel)
• BS 799-5 (oil storage tanks, steel)
• OFS T200 (oil storage tanks, steel)
API 650 (< 2.5 psig, up to 500ºF = 260ºC) / EN 14015 (max. 500 mbar or about 7.25 psig)
treats flat bottomed tanks
API 650 storage tanks are often designed to work at temperatures of up to 500ºF (260ºC).
For these higher temperature designs, the allowable stress of the material decreases. As a
result, the required wall thickness increases in a linear fashion when using the 1-foot method
and in a slightly non-linear fashion when using the variable point method.
API 620 (< 15 psig, (maximum design temperature of 250˚F.)
The design configuration of API 620 requires that you have an elevated or flat bottom on
which to store it. The tank has a single, vertical, centered axis of revolution with a minimum
material thickness of 3/16 inch.
ASME VIII (with or without stamp)
UL142 (cover steel primary, secondary and diked type atmospheric storage tanks intended
for the storage of noncorrosive, stable flammable and combustible liquids with a specific
gravity (spg) not exceeding 1.0 (H2O2 50% sg = 1.2) in aboveground applications, except
for tanks storing liquids with a specific gravity that exceeds 1.0, covered in Section 12.)
(API-650 only pertains to vertical axis, flat bottomed tanks)
Of the three standards, UL-142 is the "minimal" way to go. (In my opinion, suitable only for
atmospheric storage of petroleum products)
The process chemical industry uses ASME-VIII a lot....
DIN 6616 - Horizontal single-wall and double-wall steel tanks for the above ground storage
of flammable and non-flammable water polluting liquids (FOREIGN STANDARD) Standards
Connect.
BS EN 12285-2:2005
Workshop Fabricated Steel Tanks. Horizontal Cylindrical Single Skin And Double Skin Tanks
For The Aboveground Storage Of Flammable And Non-Flammable Water Polluting Liquids
(British Standard)
not applicable for the storage of liquids having dangerous good
Explosives Class 4.2
Substances liable to spontaneous combustion Class
4.3
Substances which in contact with water emit flammable gases Class
5.2
Organic peroxides Class 6.2
ASME vs PD 5500 and EN 13445 = ASME heavier, others lighter and more efficient vessels.
FEA Analysis = Finite Element Analysis, verify the design
ASME VIII Div. 1 is best suit for hydrogen peroxide storage in a horizontal tank for it is
volatile, unstable, caustic, prone to pressure build up etc.
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Horizontal axis, dished end tanks are ALWAYS more expensive than flat bottomed,
vertical tanks for low pressure liquid storage. You should have a good reason to be
selecting this type of tank..... "my boss said to do it this way" is not a good reason.
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Flat bottomed tanks are limited to 2.5 psig design pressure under API-650 and ASME
VIII tank rules are for storage at 15 psig and above.
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Horizontal tanks (sometimes called bullets) are economically supported on two
saddles and must resist the bending stresses generated by this type of support as
well as the concentrated stresses at the horn of the supporting saddle.
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Based on this, the answer to your question is that low pressure horizontal tanks are
commonly designed to the rules of ASME VIII with a minimum pressure of 14 psig.
No code stamp or certification is required.
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The tank cost will, of course, also be controlled by your selection of diameter, length
and accessories.
Use of ASME section VIII (no code stamp) will cover ALL TANK SIZES, ALL LIQUID
SGs and provides complete, conservative and competent designs....... like it has for
the past 75 years !
All four specifications were produced to provide guidelines for design storage tanks;
however, each specification was produce to give a specific area of the storage tank.
API 650:
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API-650 is a general specification for designing welded steel storage tank for oil
storage
Large size storage tank
Temperature: -40F to 500F
Pressure: up to 2.5 psig
API 620:
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Design and Construction of large welded low pressure storage tank
Large size storage tank
Temperature: -325F to 250F
Pressure: up to 15 psig
API 12D:
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API 12D is field fabricated tank of production liquids
Smaller in size compared to API 650/620
Temperature: Ambient
API 12F:
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API 12F is shop fabricated tank of production liquids
Smaller in size compared to API 650/620
Temperature: Ambient
API 12F is intended to use for oilfield service mostly
For further consideration regarding storage tanks
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API 12B - Bolted Storage Tanks of Production Liquids
API 12P - Fiberglass Reinforced Plastic Tanks
UL-142 - aboveground steel storage tanks are designed for storing flammable and
combustible liquids
API 653, Tank Inspection, Repair, Alteration, and Reconstruction
NFPA 430, Code for the Storage of Liquid and Solid Oxidizers
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Examples of NFPA Class 2 oxidizers include:
calcium chlorate.
calcium hypochlorite (50% or less by weight)
chromic acid (chromium trioxide)
1,3-dichloro-5,5-dimethylhydantoin.
hydrogen peroxide (27.5 to 52% by weight)
magnesium perchlorate.
nitric acid (concentration greater than 40% but less than 86%)
Comparison of Welded Steel Tank Design Standards
Standard
Description
AWWA
D100**
API 650*
API 620*
API 12F*
API 12D*
Welded
Carbon Steel
Tanks for
Water Storage
Welded
Steel
Tanks for
Oil Storage
Design and
Construction
of Large,
LowPressure
Specification
for Shop
Welded
Tanks for
Storage of
Specification
for Field
Welded
Tanks for
Storage of
Storage
Tanks
Production
Liquids
Production
Liquids
Product Stored
Water
Wastewater
Any Liquid
Any Liquid
Any Liquid
Any Liquid
Configuration
GroundSupported
Bottom
Open or
Closed Roof
Elevated
Tanks
GroundSupported
Bottom
Open or
Closed
Roof
Any
configuration
that has a
single
centered,
vertical axis
of revolution
GroundSupported or
Skirted
Bottom
Closed Roof
GroundSupported
Bottom
Closed Roof
Shop/Field
Erected
Field Erected
Shop
(Appendix
J) or Field
Erected
Field Erected
Shop
Erected
Field Erected
Tank Sizes
Any
Any
Any
Only sizes as
listed
in Table
1 (7’-6
Diameter to
15’-6
Diameter)
Only sizes as
listed in
Table 1 of
API 12D
(15’-6
Diameter to
55’-0
Diameter)
Temperature
Range
Ambient
-40 Deg. F
to 500 Deg.
F
-325 Deg. F
to 250 Deg.
F
Ambient
Ambient
Maximum
Pressure
Atmospheric
2.5 psig
(pounds
per square
inch gage)
15 psig
As shown in
Table 1 (8 –
16 oz/in^2)
based on
tank size
As shown in
Table 1 (3 –
8 oz/in^2)
based on
tank size
Materials
Carbon Steel
Carbon
Steel
Austenitic
Stainless
Steel
Duplex
Stainless
Steel
Aluminum
Carbon Steel
Austenitic
Stainless
Steel
Nickel Alloys
(Low Temp
only)
Carbon Steel
Carbon Steel
Uses/Industries Primarily for
municipal
water storage
or wastewater
process but
also found
industrially
Oil, Gas,
Chemical,
Water, and
Bio-Fuel
storage.
API 650
tanks are
API 620
tanks are
used for
product that
needs high
internal
pressure
12F tanks
are
standardized
shop tanks
built in
accordance
with API 12F,
12D tanks
are
standardized
tanks built in
accordance
with API
12D,
when water
storage is
necessary
some of the
most
common
welded
steel tanks
used in
industry.
Most tanks
in
Refineries,
Terminals,
Pipelines,
and other
process
facilities
use these
tanks.
*API – American Petroleum Institute
**AWWA – American Water Works Association
such as LNG
tanks or
Cryogenic
tanks.
including
dimensions
and internal
and external
pressures.
Primary use
is for the
storage of
production oil
& produced
water.
including
dimensions
and internal
and external
pressures.
Primary use
is for the
storage of
production oil
& produced
water.