CNG Refill Trailer

[Dick]

I know it is illegal to pull a trailer with CNG tanks connected to the tow vehicle.

How about pulling a trailer, stopping and using the trailer CNG tanks to refill the main CNG tank located on the tow vehicle?

Would some kind of a pump be necessary to make the transfer or would the pressure differential between the full tank and empty tank be enough to accomplish the task.

Just curious.

Thanks for any advise or info.

[afvman]

Re: CNG Refill Trailer

Hello New Member,

I don't think it's illegal! My understanding of NFPA-52 Vehicular Fuel Systems Code is that it is permissible unless its changed recently. Para. 6.5.10 of the 2006 edition says, "Where a fuel supply container is located on a trailer, the fuel supply line shall contain an emergency breakaway device designed to retain CNG on both sides of the breakaway point."

I've seen several applications of this and would be glad to supply contact info if you want.

In the meantime, here's a picture of an articulated bus we inspected in France that has CNG cylinders on the front and the engine in the back with a connecting hose with breakaways in between.

Interesting,

afvman/Bill

[jblue]

Re: CNG Refill Trailer

Your the best afvman! Thanks for sharing.

[Gerben]

Re: CNG Refill Trailer

Would some kind of a pump be necessary to make the transfer or would the pressure differential between the full tank and empty tank be enough to accomplish the task.

If you have an open connection (with breakaway), then you don't need a pump.

[Amfuel]

Re: CNG Refill Trailer

You need to check with the highway patrol or other regulatory agency. You may be required to have a Hazmat certification to pull a trailer with flamable fuel onboard.

[cowboy]

Re: CNG Refill Trailer

not if it is the fuel system for car or truck if it is hooked up to the motor if it is just a refueling trailer than there you might even have to plakered it and fall under all kinds of regulation why not put tanks on roof this must be done right but a lot less trouble to drive and should use less fuel than pulling a trailer