AnsweredAssumed Answered

Does double wall tank need overflow pipe and a secondary containment?

Question asked by imkevinliu on Oct 23, 2016

Dear Sir/Madam,


I am design a diesel distribution tank with 15 m3 live capacity. The tank receives diesel by piping from a 10 m3 diesel transfer tank which receives diesel from truck.

The diesel distribution tank would be a double wall tank sharing a dike with other elution and carbon regeneration equipment in a gold mine project. Ambient temperature is from 1 to 50 degree C.

Tank overfill protection: The tank will get a level transmitter to plant PCS with alarm and a level switch to stop transfer pump working when tank reaches high level. 

Is an overflow pipe with a secondary containment tank (3 m3) required? One of my colleague argues that if level transmitter fails, overfill will occur.

My opinion is: diesel distribution tank will receive diesel once the tank level is below 5 m3. With the max. 10 m3 diesel transfer tank, diesel distribution tank will get max 15 m3 diesel. So, there is no possibility of overfill. With tank overfill protection device installed, I think it would be sufficient.

Or, if it is an issue, how about to get another level alarming system installed on the tank in case of level transmitter failure?


Thanks a lot!