When it comes to storing oil, vapors, and other liquids, two common options are the API 620 and API 650 steel storage tanks. The American Petroleum Industry (API) has established rigorous standards for design, fabrication, and construction of these tanks. Deciding which tank is right for your specific requirements depends on several factors, including pressure, size, and temperature parameters.
API 620 Configuration
API 620 storage tanks can have an elevated or flat bottom. These tanks are made from carbon steel, stainless steel, or nickel alloys (if storing at lower temperatures). They feature a single, vertical central axis of revolution with a minimum material thickness of 3/16″. Additionally, all API 620 tanks must undergo inspection and receive welding certification. Due to their size, API 620 tanks are generally field erected and typically have diameters larger than 300 feet.
Benefits of API 620 Tanks
API 620 tanks are the industry standard for products with high internal pressure, such as liquified natural gas and cryogenic products. While capable of storing any liquid, API 620 tanks excel in storing contents at higher pressures and lower temperatures.
API 650 Configuration
API 650 tanks, on the other hand, are typically smaller cylindrical storage tanks. They have specific requirements regarding design, material, construction, and testing. API 650 tanks support the entire bottom of the tank evenly in non-refrigerated service, with a maximum design temperature of 200 degrees Fahrenheit, regardless of whether the top is open or closed. These tanks have a minimum material thickness of 3/16″, similar to API 620 tanks. Carbon steel, austenitic duplex stainless steel, or aluminum are commonly used materials for constructing API 650 tanks. Inspection is mandatory for all API 650 tanks, and they can be either shop or field erected.
Benefits of API 650 Tanks
API 650 tanks have the advantage of accommodating a wide range of sizes and can store contents at lower pressures but higher temperatures compared to API 620 tanks. They are widely used in the oil industry for storing oil, gas, chemicals, water, and biofuel.
Choosing the Right Tank for Your Project
Determining the ideal storage tank for your project depends on considering configuration, size, pressure, and temperature parameters. While both API 620 and API 650 tanks require inspection and can be made from carbon steel, stainless steel, or nickel alloys, their key distinctions lie in their specific applications. API 650 tanks are commonly found in refineries, pipelines, terminals, and process facilities, while API 620 tanks are designed for cryogenic or LNG storage requiring high pressure.
It is essential to consult an expert who can assess your specifications and intended usage to guide you in selecting the appropriate tank. A fabrication expert will consider configurations and pressure requirements to fabricate a tank that complies with regulations and ensures the safe storage of materials.
For your custom storage tank needs, ProgramMatek offers decades of experience in fabricating high-quality tanks for various industries. Contact us today for a quote on your next storage tank project.