Businesses dealing with petroleum products, gasoline, and other chemicals require specialty storage tanks that are up to the job and must be either API 620 or API 650 rated to pass regular oil tank inspections.

Published by the American Petroleum Industry or API, these standards ensure that companies storing petroleum and other dangerous liquids use tanks able to withstand the varying pressures of these liquids.

Although both standards relate to lower-pressure tanks used only for storage, the pressure and temperature limitations for each design differ.

An experienced oil storage tank service can help you determine those needs so your business investment is on tanks that adhere to all government and safety standards required for storing your product.

API 620 0-15 PSI Storage Tanks

The API 620 tank standard regulates the design and construction of large chemical and oil storage tanks at least 300 feet in diameter that can house contents up to 15 PSI such as liquefied natural gas (LNG), cryogenic liquids, and other low-temperature -325 to 250 degrees F, higher-pressure liquids, gases and vapors.

Because API 620 design must withstand a higher internal pressure, approved tanks installed by oil storage tank services must be cylindrical, constructed on a flat bad or elevated base, and constructed from steel that is a minimum of 3/16” thick.

Construction materials may be carbon steel, austenitic stainless steel and low-temperature nickel alloys only, an ASME welding certification is required of the manufacturer, and tank inspections by an approved non-third-party inspector are required.

API 650 0-2.5 PSI Storage Tanks

The API 650 tank standard regulates the design and construction of smaller cylindrical storage tanks in various sizes and capacities that can hold oil and petroleum products, chemicals, treated water, biofuel, and other contents up to 2.5 PSI but which have a higher temperature from -40 to 500 degrees F.

API 650 tanks installed by oil storage tank services for lower-pressure indications may be constructed from carbon steel, austenitic duplex stainless steel, and aluminium that is a minimum of 3/16” in thickness with a maximum design process temperature of 200 degrees.

They may be open or close-topped but must have an evenly supported bottom.

As with the API 620 standard, API 650 tanks also require tank inspections by an approved, non-third-party inspector and the manufacturer must hold an ASME welding certificate.

Choose the Best Tank for Your Storage Needs

Although there is a little bit of overlap in what contents each of these storage tanks may hold when considering that API 650 tanks can be upgraded to store higher-pressure contents, each is designed to safely handle two different conditions.

  1. API 620 standard storage tanks are safe for low-temperature liquids, gases and vapors up to 15 PSI.
  2. API 650 standard tanks should contain only liquids up to 2.5 PSI.

Because critical requirements such as construction materials and processes, support bases, and other details differ, each must receive tank inspections by approved professionals to ensure their safety.

Plan your purchase with an oil storage tank service to be certain that your facility is safely equipped with the right tanks!

Oil Storage Tank Questions in Oklahoma, Texas, or Surrounding Areas?

Contact Dunham Engineering For Oil Storage Tank Services and Inspections!

Call 979-413-4687 to Discuss Your Needs!