Freeboard Requirement per Add. 4 1

[jramosjr]

Hi,

I'm currently designing an API 650 tank that has been assigned to SUG I. Per Table E-7, the minimum required freeboard is 0.7d if SDS < 0.5g. What happens if SDS >= 0.5g? The table does not specify what to use if SDS >= 0.5g. Should the freeboard be equal to the wave height should this be the case? Also, the statement in E.7.2, “The purchaser shall specify whether freeboard is desired for SUG I tanks” does add confusion to the situation. The title of Table E-7 is “Minimum Required Freeboard.” Could someone shed some light this direction?

Jorge, Jr.
Alonso & Carus Iron Works, Inc.
Euro-American Steel Co., Inc.

 

[JStephen]

Refer to the similar, but more complete, Table 15.7-3 in ASCE 7-05.

For SUG I, it still shows "no minimum freeboard is required" for SDS>0.5g.

 

[jramosjr]

Thanks JStephen. I checked teh ASCE 7-05 and you are correct.

Jorge, Jr.

Jorge L. Ramos, Jr., MSCE, PE
Alonso & Carus Iron Works, Inc. (

http://www.alonsocarus.com)

Euro-American Steel Co., Inc. (

http://www.euroamericansteel.com)

 

[jramosjr]

I wonder why API 650 App. 4 did not include the same table as in ASCE 7-05. Why have they chosen to left out the condition for SDS >= 0.5g? Does anyone know?

Jorge L. Ramos, Jr., MSCE, PE
Alonso & Carus Iron Works, Inc. (

http://www.alonsocarus.com)

Euro-American Steel Co., Inc. (

http://www.euroamericansteel.com)