Does anyone know if an aux tank that will hold diesel needs to have a roll over/tip over valve? and if it does, where I could get one?

I built a fuel tank, roughly 50 gallons and I'm going to be installing it shortly.

I have a cap like the one on on the tank in this pic..
Contico Liquid Storage Tank — 37-Gallon, Black | Fuel Transfer + Storage Tanks | Northern Tool + Equipment

If I would flip the tank upside down the cap will leak out fuel because of the way it vents. The reason I bought it is because all of the tanks I have seen at Northern Tools and the farm store here in town use it.

I was on the Northern Tools webpage looking for some stuff and I noticied that they now call these tanks "transfer tanks" which aren't DOT approved
vs the aux tanks which are DOT approved. I'm guessing it's because of the roll over valve.

Now either one is going to be in the truck anyhow though, so I'm not sure how that works out?

 

Off topic, sorry, but if DOT approves one as an "auxillary tank" it cannot spill diesel fuel all over the highway in a roll over crash? But, if they don't approve of a "transfer tank" it is still alright to carry in the back of your truck, permanently and it is alright for these tanks to spill diesel all over the highway in a roll over crash?? Did I miss something??? Or is this just another way for someone to make more money?? Sorry again, don't mean to hijack the thread, but that just made me go...."huh????"

 

That's pretty much correct.

I would say after reading the regs, that transfer tanks are not legal to put in a truck that is on the road.

They'd be fine on a farm truck that is just running around the fields to fill equipment.

I just need to find a source for a vent/roll over valve and my tank will be ok.

 

Wondering something here...

If I would "T" into the stock tank vent line, would that work to vent the aux tank??? I'm talking about the vent line that runs along side the fill pipe.

I'm not sure how the stock tanks venting system works exactly, hoping someone knows.

 

I think the reason some tanks are not dot approved is that they have to be double walled.Here in canada anyways

 

I have had an aux tank in my truck now for 3 years, single wall, and the truck needs to be safety inspected every year and has passed every year with that tank in it. I am from canada to, and there is no law where i live that says it has to be double wall,,,, now I have heard they were trying to pass that, but it has not yet,, It does how ever HAVE to be bolted to the frame like a 5th wheel hitch,, cant just be bolted to the box floor. As for the cap,,, your factory cap would leak diesel out if you laid the truck on its side with the fuel cap facing down. Thats because they vent the tank with the cap.

 

The stock cap isn't vented as far as I know.

 

Stock cap HAS to be vented,,if not the vacuum from sucking the fuel out would colaspe the stock tank.

 

Should be a roll over vent on the top of the tank I think.


Anyhow, I found a place in Oregon that sells the roll over valves for ~$10 ea. Also sell caps, etc.

 

If I over fill my main tank from my Aux. tank, diesel fuel will run out of the top of my main tank, so thats maybe where my air vent is or something is wrong. It was that way from day one. My air vent on my Aux. tank is on top of the tank, and it is a pet **** with a plastic tube that sticks down between cab and the truck box. I installed this myself, so when I drain my Aux tank I just open the air vent. waam Holland, Mich.