Tmin calculation on low pressure storage tank

[MarikaF]

What do I need to take in to consideration when I calculate the tmin of the shell on a low pressure storage tank? Can I still use the plain old API 653 calculation? It's a plain Hemispheroid with a knuckle radius, 2.5 psig internal pressure. This is an existing tank built in 1990.

Any and all help will be appreciated!

Thanks,
Marika

 

[MATEGRITY2009]

Pls check to API STD 620 details.

 

[DSB123]

If it's a FFS assessment then API579 is a more appropriate Code to use. API 620 is for "new" tanks. API579 is for assessment of "in service" equipment.