water drawoff sumps of API-650 tanks

[erdd]

I would like to know how many water drawoff sump pits should be provided for above ground storage tank (150 FT diameter, 70 FT height, 200,000 BBLS capacity, design temperature 70 C). The tank will be constructed as per API-650. The product is Gasoline and tank bottom is designed to concave up in the center when the tank is full of products (periphery will be lower than center of bottom plate)

I appreciate any advice from API-650 experts, thanks.

 

[786392]

Dear Hello/Good Afternoon,
Kindly do Check first if Height Vs Diameter ratio is within safe limits as per API 650 Etc.

Best Regards
Qalander(Chem)

 

[khardy]

This is an owner / operator preference. I would think (4) would be typical. No less than three.

 

[IFRs]

API-650 is silent on this question. No requirements per code. You could have none, you could have 12. It is, as stated above, an owner / operator preference. One way to look at it is to put one near each shell manway - how many shell manways are there? If you are going to recirculate using piping to the sumps to feed the pump, the hydraulics of the situation might help you decide.