Question on if a Day Tank is Needed??

[michael333]

I have question on whether or not I need to remove an installed day tank?

I have an aboveground 5K gal fuel storage tank,
a Pryco 150 gal day tank, and a generator set that's all installed outside on a concrete pad. Both tanks and generator set are all on the "same level" conc pad. Level of fuel in the 5K gal tank is approximately 5-6 feet above the top of the day tank.

20 feet separates the 5K gal storage tank and Pryco day tank. The Pryco day tank is installed within 3 feet of the generator set.

Bottomline: If I eliminate the day tank, THEN the transfer pump that comes with the generator set package must be able to transfer fuel between itself and the 5K gal fuel storage tank?? Only answer that I know of.

I've looked at the IMC-2003 and NFPA-30 and found nothing
that states you must have a day tank between the storage tank and generator set. Is there another NFPA section that I need to look at for this application?

Any input from someone out there would be greatly appreciated. I don't deal much with these type of applications.

 

[flyrfan]

I would contact Prefered Utilities,

http://www.preferredutilities.com/

they manufacture fuel oil distribution components and know the applicable NFPA codes for your application.

Good Luck.

 

[Bribyk]

NFPA 37 "Standard for the installation and use of stationary combustion engines and gas turbines"?

 

[quark]

As far as I know, the return line from the injector shouldn't have any lift. Just check if your day tank return entry is below the injector level. If that is the case, better to keep the day tank. What does the Generator manufacturer say?

 

[AbbyNormal]

the best thing a day tank does is it let's diesel warm up

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[willard3]

Also, if you have a storage tank pump failure, the day tank gives you enough time for orderly shut-down.

 

[stookeyfpe]

Pryco tanks are crap. In every installation I dealt with using Pryco equipment, I condemned the installation as the local AHJ. As a result I enjoyed lots of meetings, talking to Pryco staff who really had no clue, and the contractor sniveling all the way through the process.

A Pryco tank can be specified as being listed or as not being listed, the emergency vents were designed by idiots and were not in compliance with NFPA 30 or NFPA 37. Low bid, low quality components.

Also, if this an aboveground and outdoor installation, why not use a conventional UL 142 generator sub base tank and avoid all of the extra pipes and components?

 

[cry22]

NFPA 110.

 

[EEJaime]

Micheal333,

Well since it is already installed as you stated, some of the options listed in this thread aren't feasible, but we find that the day tank is generally a good idea as it allows for very quick startup and regular fuel replacement and there is very little question that the fuel pump on the generator can handle the head in the fuel line.

I am assuming this is a Standby generator? The one thing that you need to watch with a day tank is that the unspent fuel that gets pumped through the generator is heated, and if it is returned to the day tank, the generator may need to be derated as the diesel engine is less efficient with hot fuel. We have pumped the hot fuel back to the main tank to let it mix with the greater volume in there thus minimizing the temperature rise. I think Caterpillar had problems with this issue.

 

[alehman]

I've been told the most important item is to keep the fuel level in the tank (day tank, or main tank if no day tank) below the level of the injectors.

It's fairly common to use a fuel cooler when a day tank is involved to help with heating. They can be installed in front of the engine radiator or as a separate box with an electric fan.