Elevated Horizontal Tanks

[chicopee]

I had this question in the API forum and had no response--probably the wrong forum.

Horizontal A.S.T.'s, supported by structural steel frameworks, are 10' above ground level. These tanks contain diesel fuel and kerosene and are in a diked area. Dike walls are 48" high.

Should the steel legs supporting these tanks be protected from fire with fire resistant material in order to comply with NFPA combustible and flammable liquid code?

If "yes" what type of material is acceptable and yet be resistant to the elements--rain,snow and ice.?

 

[cdafd]

what size tanks

 

[chicopee]

Each elevated tank is slightly over 10,000 gallons and each contain diesel fuel. There is no dispensing, just bulk storage transfer by trucks.
This location is somewhat isolated and is typical of rural installations prevelant in past decades.

 

[IFRs]

Reinforced concrete footings and pedestals

 

[chicopee]

Volume of each elevated tank is over 10,000 gallons

 

[stookeyfpe]

Fire resistive protection of the columns is required by NFPA 30. The problem with NFPA 30 is that it does not give you any criteria for the protection of the columns. IFR is kind of correct, but my problem with the answer is the thickness of the concrete. I can give you an answer but I don't have enough information to make any reasonable decision.

To protect steel structural elements from an external hydrocarbon pool fire, your selected assemblies should comply with ASTM E 1529. In the US, Carboline makes some off the shelf assemblies, but they are not inexpensive. Second, and as important, is that the column weight/ft. must support the dead load of the insulating material.

 

[chicopee]

I've heard of a substance that can be coated on the steel legs and during a fire, this coating will expand and protect the steel. Any experience with this material?

IFR, are you suggesting that the steel legs be replaced with reinforced concrete or pedestal?

 

[stookeyfpe]

Chicopee

Your talking about an intumescent material. I am not aware of such a product for protecting a steel structure from a hydrocarbon pool fire.

 

[chicopee]

Stookeyfpe, thanks for the tip. I checked the web and there is spray on intumescent material. I'll do a further check of commercially available material for their fire resistance.