Water Filling Rate

[hamidun]

Dear All,

As per API STD 650 section 7.3.7.5, in tank portion column, there are two tank portion for bottom course thickness less than 22 mm, can someone help me the difference between top course and below top course. How those portion have different maximum filling rate?

If we have tank with 7 shell ring course, which one is top course and below top course, please help, I don't get what this section means.

Thank you.

 

[JStephen]

The section is saying that you reduce the filling rate as you approach full capacity.
For a tank with seven courses in the "less than 22mm" group, you use the higher filling rate until the water reaches the top of the 6th course, then reduce the rate while filling the remainder of the tank.
For example, if each course is 2m high, you fill it 12m deep at 460mm/hr, then the remaining 2m at 300mm/hr.

 

[hamidun]

Jstephen,

If it is like that, when we have a tank with 44 m diameter, 14 m height, each course is 1,828 m, it will take 260 hrs = 11 days to fill one course of the tank, with filling rate 300 mm/hr?

Is my math correct?

 

[JStephen]

Presumably 1828 mm per course, but 1828 mm/ 300mm/hr = 6.1 hrs for a course.

 

[hamidun]

But we have to adjust with the pump as well, right?

So, in my math for a tank with 44,6 m diameter, 12,8 m height, each course is 1,828 m, if we want to satisfy API 650 requirement, we need a pump with capacity around 500 m3/hr for each course.