pplbb2012
Structural
- Dec 2, 2009
- 10
I am not sure whether API can be discussed in this forum, but hope i can get your great support.
Story comes from my confusion on item 7.3.13 of API RP 2030:
Atmospheric storage tanks generally do not warrant fixed water spray protection and (with the exception of horizontal
tanks) do not readily lend themselves to this type of protection. When reviewing an atmospheric storage tank’s protection from an external fire the design personnel should recognize that cooling water is of potential benefit only for the exposed portions of the roof and for those portions of the shell that are not in contact with the liquid contents. Those portions of the tank most likely not to be in contact with liquid include the roof of cone roofed and covered floating roof tanks and the upper portion of the shell on all tanks. If spray is used, typically only the upper 12 to 24 ft (3.7 to 7.4 m) of shell is sprayed; up to 12 ft (3.7 m) of rundown is allowed on inclined and vertical surfaces. If there are wind girders at the top of the tank, spray nozzles should be placed below each girder ring.
In my current design of water spray for a 20,000m3 ADO tank (with other ADO and ULP tanks surrounded), tank height has been up to 26m, i am not sure whether the protection shall focus on 12ft to 24ft only, or the full height above 12ft shall be guaranteed.
Can someboday teach me how to apply this code request into my design? Thanks.
Story comes from my confusion on item 7.3.13 of API RP 2030:
Atmospheric storage tanks generally do not warrant fixed water spray protection and (with the exception of horizontal
tanks) do not readily lend themselves to this type of protection. When reviewing an atmospheric storage tank’s protection from an external fire the design personnel should recognize that cooling water is of potential benefit only for the exposed portions of the roof and for those portions of the shell that are not in contact with the liquid contents. Those portions of the tank most likely not to be in contact with liquid include the roof of cone roofed and covered floating roof tanks and the upper portion of the shell on all tanks. If spray is used, typically only the upper 12 to 24 ft (3.7 to 7.4 m) of shell is sprayed; up to 12 ft (3.7 m) of rundown is allowed on inclined and vertical surfaces. If there are wind girders at the top of the tank, spray nozzles should be placed below each girder ring.
In my current design of water spray for a 20,000m3 ADO tank (with other ADO and ULP tanks surrounded), tank height has been up to 26m, i am not sure whether the protection shall focus on 12ft to 24ft only, or the full height above 12ft shall be guaranteed.
Can someboday teach me how to apply this code request into my design? Thanks.