UNDERGROUND VS ABOVEGROUND DIESEL FUEL TANK FOR STANDBY GENERATOR

[nkyprianou]

I am working as a site mechanical Engineer in a Housing Project in Saudi Arabia (Hot and Humid Climate) which will accommodate more than 3000 people. We have 5 standby generators in the
project and each one is feeded by a built-in day tank and 1 diesel fuel storage tank (around 3000 gallons-11356 liters). According to the
specifications (copy attached) our main fuel storage tanks shall be of underground type.

Unfortunately one out of five tanks could not be installed underground due to civil construction
obstructions on the specific spot (it is an enclosed yard next to a sports complex where there are
HVAC Package units located near the tank 2-3 m close distance and around 15m
away from the Generator enclosure that is also in the same yard), also cannot be moved to another location.

My specific questions are:

1. Do you believe would be fissible to install the tank aboveground taking into account the above conditions?
2. Why the specifications of the site mention that the tanks have to be of underground type?
3. Are there any limitations on the capacity of the diesel fuel tank that can be installed above ground?
4. Can you give me any arguments/points to support the installation of the above mentioned tank above ground?
5. Can you send me written proofs from any specifications to support the installation of emergency/standby generator diesel fuel tank above ground?

Thank you in advance,

Regards,

Nicos








30.34.10 Fuel Supplies



(a) Main Fuel Tank



The main fuel tank shall have the capacity for 72 hours continuous operation of the generating set at full load.

It shall be of the underground type and shall be installed a safe distance from the engine generator set.

 

[civilperson]

You want us to do your job for you? OK, Aboveground tanks require secondary containment for spills, (and fire protection), and the volume increase due to temperature rise can not be used for topping off the tank.

 

[Zambo]

civil person is correct. You will need a bund wall around the tank which provides containment for 100% of the tank volume.

Of course the foundation, tank and supports must be designed.