Maximun working level for a Butane storage tank (52 ft sphere)

[airbus]

How will you determine the maximum working level of a Butane (51.6 psia @ 100°F) storage tank (sphere) which has PSV's set a 100 psig? How will this level vary with higher vapor pressure (i.e. say you store material with a 72.2 psia)?

 

[Compositepro]

If I recall correctly, propane tanks are not to be filled more than 80%. I would think that butane has the same requirement. The issue is not really vapor pressure but that liquid density changes quite a bit with temperature. If you run out of vapor space the pressure will rise very quickly due to liquid expansion.

 

[MJCronin]

I am guessing a bit here.....

But I assume that no design drawings are available from the original sphere fabricator ?

Did your company purchase the facility with any records ?