hi,
lets say your U value is 152,88 cbm(vapour space of the tank at required innage level) and LR value is 800cbm/h(loading rate of the tank in cbms) so;
CT: 3600/(152,88X800)=29,4sec
I hope this might help

Hello,
Can some here explain the use of formula
In item 18.8.2 of IGC code for the calculation of ESD valve closure time.
Formula:
3600 U/LR
Where U ullage volume at operating signal level and LR maximum lloading rate.