Water Spray Protection Design for Storage Tanks 2

[jhgf]

Hi Everybody!

API 2030 specifies design criteria for water spray protection for the tank shell of atmospheric storage tanks. It does not give any requirements for the distance from the shell to the open spray nozzles. From my point of view this is necessary due to the impact of wind.
Are there any other documents i can refer to?

Tank you!

 

[DavidCR]

Nozzle data sheets (for example Viking model E, Tyco D-3) include geometric characteristics on the spray pattern, they include recommended distances. What I do is to model in 3D Autocad the pattern as a key to observe the correct location of the nozzle.

For cooling tank walls what has worked to me to avoid wind effect is to consider a good degree of spray overlap, ie. playing with the nozzle to nozzle distance, the distance to the wall is based on the nozzle data sheets. If wind is too strong maybe additional rings will be needed. Some recommend additional rings for tank walls taller that 7m.

If wind can be an issue be careful if you are considering the water rundown.

Depending on the size of the tank, contents and the geometry involved in the fire exposure you are protecting from, the nozzle distribution criteria can change a lot. For example a class I fuel on a small vertical tank needs full spray coverage, a big class II fuel tank that is usually full may need emphasis on spray protection on the upper ring, in aprox terms.

 

[stookeyfpe]

FYI, NFPA 30 doesn't require water spray protection for atmospheric ASTs.

 

[jhgf]

Thanks a lot!