Comparison of Welded Steel Tank Design Standards

We are often asked about the differences between the varying tank standards and when they are used. Below is a simple table which provides a quick review of the several welded steel storage tank standards. The list is not all-inclusive, there are tanks which fall outside these parameters. However, we have covered some of the more popular standards used. If you have questions in regards to this list or would like further information on welded steel storage tanks please visit our website www.advancetank.com or by phone at (970) 568-3444.

 

Standard

AWWA D100**

API 650*

API 620*

API 12F*

API 12D*

Description

Welded Carbon Steel Tanks for Water Storage

Welded Steel Tanks for Oil Storage

Design and Construction of Large, Low-Pressure Storage Tanks

Specification for Shop Welded Tanks for Storage of Production Liquids

Specification for Field Welded Tanks for Storage of Production Liquids

Product Stored

Water

Wastewater

Any Liquid

Any Liquid

Any Liquid

Any Liquid

Configuration

Ground-Supported Bottom

Open or Closed Roof

Elevated Tanks

Ground-Supported Bottom

Open or Closed Roof

Any configuration that has a single centered, vertical axis of revolution

Ground-Supported or Skirted Bottom

Closed Roof

Ground-Supported 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 when water storage is necessary

Oil, Gas, Chemical, Water, and Bio-Fuel storage. API 650 tanks are 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 620 tanks are used for product that needs high internal pressure such as LNG tanks or Cryogenic tanks.

12F tanks are standardized shop tanks built in accordance with API 12F, including dimensions and internal and external pressures. Primary use is for the storage of production oil & produced water.

12D tanks are standardized tanks built in accordance with API 12D, including dimensions and internal and external pressures. Primary use is for the storage of production oil & produced water.

*API – American Petroleum Institute

**AWWA – American Water Works Association