Is anyone familiar with recommended API 650 retention times? I am looking for the retention time for a 400 BBL API 650 oil storage tank. The oil is API 35 degree oil.
I cannot find anywhere in API 650 that specifies a retention time.
I suspect this is a process related question and API 650 is not going to address for you. However, some more explanation what you want will get you a better answer.
Maybe you are referring to the time between inspections? This is calculated following an inspection according to API 653 (Tank Inspection, Repair, Alteration, and Reconstruction). API 650 (Welded Tanks for Oil Storage) is used for the construction of your tank.
Inspections according to API 653 need to be done by an authorized inspector, of course all described in given code.
My vote on what retention means is how long the hydro test water must sit in the tank. 24 hours is common, but long enough to ensure that you have adequately inspected all joints. It shouldn't take long. 400 bbl is a pretty small tank.