Challenge
A refinery contacted Envent to have a 150,000 barrel internal floating roof degassed for inspection. The tank contained gasoline, which has a high BTU/cubic foot, so a correctly sized thermal oxidizer is critical.

Solution
Envent’s engineers properly sized a thermal oxidizer for the tank degassing using the product’s BTU content as well as flow capabilities of the tank design. Envent also informed the customer that water washing cannot occur until the LEL level is below 50%. Envent matched the outgoing flow of the pump once the roof was landed so the tank vapors could be captured and destroyed without collapsing the roof because of too much vacuum applied to the tank.

Benefit
The refinery was able to learn from Envent that water washing above 50% can be dangerous. Envent showed the customer that tank degassing can be done safely and quickly. The refinery was able to do the tank inspection before the inspection date limit to avoid a costly fine.