NFPA30 Section-4 Storage Tanks

[MGO1]

Here is the situation:

Client purchased a facility that was shutdown about 5-years ago. There are (3) 66' diameter x 44' tall API-650 Storage tanks that they wish to use to store Ethanol.

This is Class 1D flammable liquid.

The tanks are inside a containment dike and are situated in a straight line. There is only 12 ft between the middle tank and each end tank.

NFPA-30 Section-4 states (paraphsed from table) that: The space between tanks shall be a minimum of 1/6 the sum of the diameters of adjacent tanks.

THis appears to mean that the space between the middle tank and either end tank needs to be 1/6 x 2 Tanks x 66' diameter = 22 ft.

Conclusion is that only the 2 end tanks can be filled at any one time with Ethanol.

QUESTION: Is there any way around this? i.e. installation of other systems like foam, water spray, etc. that would allow for closer spacing? Or am I interpreting the code incorrectly.

P.S. The tanks were originally used to store Sulfuric Acid so there was no need for NFPA-30 in the original intended use of the tanks.

Thanks!
Mike

 

[JStephen]

Assuming the installation needs to meet NFPA 30, it looks like you are interpreting it correctly.

When going from acid tank to an ethanol tank, check into emergency venting also.