hi
Well i think there is a confusion in understanding the question.
i need to calculate the breath in and breath out capacity of breather valve dia 6" ?

i have done all other calculations from API 2000. dear i m confused in calculating the capacity of 6" valve.
there are four breather valves installed on the roof of tank.
total breath in requirement including max out flow and thermal breath in are..


for liquid movement out

1673.2NM3/hr =62696.8SCFH

Table 2A
for thermal inbreath

1695.405NM3/hr =63369.6 SCFH

Total=
3368.605NM3/hr =126066.4SCFH



Breather valve rated capacity = -----------

Please help in breather valve capacity dia 6" , 4No.s. so that i can evaluate that existing breather is sufficient or needs to replace......

thx and best regards
JH