FM Approved Tanks

FM Global is one of the leading property insurance companies in the world, and their approval for steel tanks is a clear mark of quality. This third-party certification from FM is to ensure that the particular tank that is being designed is to the highest standards.

Their approval is based upon a satisfactory evaluation of the product and the manufacturer in the following major areas:
  • The structural integrity of the tanks needed to withstand anticipated design conditions
  • The ability of the manufacturer to properly design, fabricate, and install bolted steel tanks in accordance with industry regulations
  • The ability of the manufacturer to provide a highly reliable and durable structure for the storage of water for fire protection purposes

FM 4020 are essentially the same provisions for steel tanks, but to a higher degree. In order to be approved, facilities and building materials must be tested, inspected, and certified according to FM QC requirements. The manufactured tank as well as the drawings and calculations must be stamped to prove that they are up to FM’s standards.

FM approves specific types and sizes of tanks to be installed in various designated seismic zones and categories/occupancies.

FM recognizes the following five earthquake seismic criteria:
  • 50-year
  • 100-year
  • 250-year
  • 500-year
  • >500-year

These seismic categories are based on the return period of a seismic event of damaging ground motion.


FM 100 YR Tank

  • 42’ x 34’ 300,000 Gallon Fire Water Tank