Generator AUX fuel Tank

[Chainbreaker]

On my #2 spare MEP-002a on M116A2 trailer I knew it needed an onboard auxiliary fuel tank installed but I hadn't gotten around to it. This notion was further reinforced last winter when this unit was brought into action when my #1 generator had a malfunction in the midst of a week long power outage during a really bad power-pole snapping ice storm. It got old really fast hefting full Jerry cans up to trailer height and holding in place to refuel the tank everyday.

So the search was on this summer for an all aluminum fuel tank! While cruising through Craig's List I found a used aluminum 50 gallon Dura Craft "reefer tank" for $60. It had quite a bit of road grime and the cradle brackets and straps were badly rusted. But I figured for $60 it was worth a shot at repurposing this old semitrailer tank. Before I agreed to make the drive to buy it I had the seller check that it was good on the inside and did not have any baffles. If it had baffles it would make it pretty much impossible to pressure wash the inside. The seller said it was shiny new looking inside and had no baffles inside.

So I made the hour drive to pick it up and it checked out, so I brought it home and began work on it. As I power washed it big flakes of rust came off the brackets and straps. I power washed the tank inside and out. The outside road grime, comprised of old sticky diesel and road tar, was impossible to get off. So I took an angle grinder with flap wheel to outside knowing I was going to paint it so swirl marks were not an issue. I used OSPHO acid treatment on the steel brackets and bands to treat the remaining surface rust. I then primed the tank, brackets, bands with two coats of primer sanding between each coat. I put two final coats of Rapco 383 Green on it and installed new rubber on bands and brackets. I purchased all the necessary fittings, hose and a desiccant breather for the vent. After rotating brackets 180 degrees from the original "hanging position", it mounted on the trailer deck nicely leaving lots of breathing room for airflow into genset cooling intake. I now have approximately 170 hours of runtime fuel onboard (including genset day tank).

A couple of nice features with this tank is it has a 2nd draw tube (I plugged it closed) that could be used as return line if using as a "primary tank" along with a fuel gauge and a nice drain sump to collect water and sediment. Anyway, just wanted to let others know that these aluminum Dura Craft reefer tanks make excellent aux tanks for trailers or possibly other applications.

 

[robson1015]

Super nice !!!

 

[uniquify]

Anyway, just wanted to let others know that these aluminum Dura Craft refer tanks make excellent aux tanks for trailers or possibly other applications.

Nice job! That turned out great!

I've been thinking about doing something similar on a trailer that my nephew and I are building. What are the dimensions of that tank?

 

[Chainbreaker]

...I've been thinking about doing something similar on a trailer that my nephew and I are building. What are the dimensions of that tank?

My tape measure dimensions are as follows:

Tank Barrel length = 33 1/2"

Tank Barrel + fill neck length = 37"

Tank barrel diameter = 22" *

* Drain sump = 10" Long x 3" Tall x 3" Deep (not included in above tank barrel dia)

Tank height as mounted from trailer deck to top of fill neck = 27 1/2"

 

[Chainbreaker]

Here is a photo of the tank placard. Its a 2006 tank with a P/N: 9207C03C01 if that helps:

 

[Chainbreaker]

Exact dimensions, located under 50 gallon "design print" are found here under view product:

American Mobile Power | 22" Diameter Reefer Tanks

I googled "reefer tank" and got several hits. If anyone were to find a used tank without brackets & straps... do not despair, they sell the brackets and straps individually:

https://www.4statetrucks.com/fuel-t...m-reefer-tank-60-gallon-reefer-tank_29531.asp

edit fixed broken 404 link etc.

 

[1800 Diesel]

Chainbreaker,

Great installation--I need to do the same thing on two of my generators mounted on trailers. I was wondering about the third photo (on post #1) showing the line coming out at the bottom. Is this the supply line feeding the aux pump? Does it run up and back down to near the bottom of the tank? If it pulls directly off that "sump" area you'll end up sending water from condensation straight to the main tank. Maybe I don't have the right understanding of the setup but wanted to mention my concern. Hopefully I've got the wrong picture of how the lines are configured. Bottom line it's a very clean and well done installation...now I have some inspiration!

 

[jbayer]

Chainbreaker,

Great installation--I need to do the same thing on two of my generators mounted on trailers. I was wondering about the third photo (on post #1) showing the line coming out at the bottom. Is this the supply line feeding the aux pump? Does it run up and back down to near the bottom of the tank? If it pulls directly off that "sump" area you'll end up sending water from condensation straight to the main tank. Maybe I don't have the right understanding of the setup but wanted to mention my concern. Hopefully I've got the wrong picture of how the lines are configured. Bottom line it's a very clean and well done installation...now I have some inspiration!

He covered it, first post, 4th paragraph.

"A couple of nice features with this tank is it has a 2nd draw tube (I plugged it closed) that could be used as return line if using as a "primary tank" along with a fuel gauge and a nice drain sump to collect water and sediment. Anyway, just wanted to let others know that these aluminum Dura Craft reefer tanks make excellent aux tanks for trailers or possibly other applications."

 

[Chainbreaker]

Yes, jbayer is correct that is sump drain line. I just added a clear hose long enough so I can drain off the trailer into a waste diesel bottle. The clear hose allows me to see when the fuel is no longer cloudy and when tube runs clear, I can quickly shut off. The nice thing about the enclosed sump at bottom is that it has a ~quarter size hole in bottom of tank that allows water & sediment to drain into sump to be captured there. When you refuel you are not stirring up sediment off the bottom of tank. The tank being round, as opposed to a flat bottom tank, concentrates sediment/water in the tank valley where it is more easily captured into sump.

Attached is a rear angle photo showing aux fuel line coming off middle bung which has a draw tube that draws ~ 2" off bottom. The capped bung to right is another draw tube that could be used to return fuel back to tank if tank were to be used as a "primary fuel tank". A person might desire, rather than purchasing a new day tank, to just pull fuel from a large tank such as this one which is aluminum and will not rust out. Using a large tank like this as a primary would also negate having a low fuel auxiliary transfer switch as well as not requiring a aux solenoid valve and fuel transfer pump. Less sensors, pumps & hoses = more reliable fuel feed and less to maintain. However, since all my aux fuel transfer equip is working and day tank is sound I will use as is and only convert to a primary tank if something in aux circuit were to later fail or day tank rusts out.

 

[1800 Diesel]

He covered it, first post, 4th paragraph.

"A couple of nice features with this tank is it has a 2nd draw tube (I plugged it closed) that could be used as return line if using as a "primary tank" along with a fuel gauge and a nice drain sump to collect water and sediment. Anyway, just wanted to let others know that these aluminum Dura Craft reefer tanks make excellent aux tanks for trailers or possibly other applications."

jbayer,

Thanks for clearing that up. In my haste heading out the door this morning I didn't read the whole post. My bad...yep--the drain line works out perfectly and again, Chainbreaker--a great setup and great work! I need to get busy on mine now!

 

[NATCAD]

Looks tight and sweet!

 

[Haoleb]

Nice job. When I added an aux tank to my genset trailer that is the same tank I wanted to get and I actually got one from a junkyard only to find there were holes in it underneath the bands.. After ordering a new fuel gauge and cap of course...

I took it back and got a different tank off of a volvo truck that took me about a week to dissolve the sludge in the bottom and get the inside clean.

About the breather thing you have on there, this is the first time I have seen one of those. Are they necessary? The vent on my tank just has a sort of spill protection check valve and I just have about a foot of hose attached that goes into open air. Wondering if maybe I should just put a ball valve on the breather so I can keep the tank sealed when it is not being used.

 

[TaylorTradingCo]

Fuel tank

I have this really nice stationary fuel tank that would be ideal for a similar application.

 

[DieselAddict]

I have a tank from a MEP003 parts machine that I plan to mount on the trailer with the MEP803.

 

[Bmxenbrett]

Great! Now i need to find a trailer for my set..and a aux tank. Really nice setup you have there Chain.

 

[Chainbreaker]

...About the breather thing you have on there, this is the first time I have seen one of those. Are they necessary? The vent on my tank just has a sort of spill protection check valve and I just have about a foot of hose attached that goes into open air. Wondering if maybe I should just put a ball valve on the breather so I can keep the tank sealed when it is not being used.

Yes the vent on yours, if tank is off a road vehicle, should have a vent on top that has an integrated "rollover valve" incorporated in it. In a rollover accident it prevents the entire contents of fuel tank from draining out because it has a ball bearing inside vent assembly that seals up against a circular seat in vent (think O-ring) when inverted. In normal upright position it sits down in a recessed pocket with vents around the side of it and it acts as a normal vent. A vent is necessary, but a desiccant breather filter is not absolutely necessary. I only added one to insure little to no moisture enters tank, as "water is the enemy" especially if there is any Biodiesel added to fuel; Oregon requires 5% Biodiesel in all diesel fuel, with some stations offering B20. In my installation I removed the rollover vent valve in order to adapt it to accept a brass riser and shutoff valve and then the desiccant filter on top. However, I kept old rollover valve/vent assy in trailer's storage bin in case I ever need to reinstall for road travel. My thoughts were same as yours, in that when not in use I can close off the vent and have it sealed pretty much like a 55 gallon drum. Hopefully fuel will keep longer without the tank breathing every day, especially here in winter we have very high humidity/rain and during summer months it gets quite dusty during haying season. When I have genset running, of course I will have the shutoff valve open so fuel transferred out of tank can be replaced with air that is hopefully de-wetted and filtered.

 

[Chainbreaker]

Also, for those contemplating adding a large aux tank on front section of trailer...a 50 gallon tank adds about 355 lbs. of additional tongue weight when tank is full. So unless your a hulk you won't be lifting the tongue by hand to mount up to hitch. After fiddling with a Hi-Lift farm jack on my other trailer mounted generator with smaller aux tank and nearly having it slide off jack (danger, danger Will Robinson!) I opted for a retrofit jack leg. I believe these jack legs were used on the newer M116A3 trailers as well as others. I was able to purchase two of them from a SS member (CUCVFAN) who had a stock of new ones. Now with those installed, adjusting the trailer height for lunette to mate with pintle is soooo much easier after I swapped the drop landing leg for a jack leg.

 

[Chainbreaker]

Here is the jack leg installed with the old one shown for reference:

 

[Bmxenbrett]

Hi lift jacks are almost always a danger. I hate useing mine for anything.
How much tongue weight do you have with out the aux tank full?

 

[Chainbreaker]

Hi lift jacks are almost always a danger. I hate useing mine for anything.
How much tongue weight do you have with out the aux tank full?

Not sure of tongue weight with aux empty. However, an aluminum 50 gal tank with cradle & straps weighs around ~70 lbs empty. As I recall, with a MEP-002a mounted on M116A2 trailer (no aux tank), the tongue could be raised by one person. I remember it being a bit of a heft to get tongue up but once in the air it felt almost neutral balanced. With an empty aux tank the added ~70 lbs so far forward might make it difficult for one person to raise without assistance.

Yeah, I think Hi-Lifts have their place (4 wheeling) but once you get something jacked high in the air on it, if not stable, stand clear! Once it starts to lean it can go over fast! One of the best uses I had was using it as a spreader bar using a 2x4 or a fence post to extend its reach.