CNG Refueling Interlock Device

[mravi]

Hi Everybody,

I am Ravi and new to this forum. I have a doubt.

Whether all the CNG vehicles in USA or Europe have refueling interlock device to disable starting of engine while refilling the gas.

Can any one clarify this?

Bye
Ravi

[CraziFuzzy]

Re: CNG Refueling Interlock Device

Ravi,
First, welcome to the forum. To answer your question, no, there is no interlock device on any vehicle I've ever used (be that CNG or gasoline/petrol). I believe most locallities have laws requiring fueling to be done in accordance with posted warnings, and all stations do have signs stating that fueling is not to be done with the engine running, but there is no engineered device to prevent this. It is up to the operator to fuel their vehicle safely (this applies to all forms of fueling).

As a comment to your question, I'd like to point out that there is FAR less risk of any sort of ignition with CNG fueling than with gasoline/petrol, as any small leak from CNG will dissipate faster than it can acucmulated to explosive levels, while petrol fumes will collect on the ground below the car (if not recovered properly) and have a much greater chance of finding an ignition source.

[larrycng]

Re: CNG Refueling Interlock Device

Welcome Ravi.

Yes, there starter interlocks available to prevent a vehicle from being started during fuel and while the CNG fueling hose is connected to the vehicle. These devices are used mostly in fleet application; transit bus is one where I have seen them used.

In the early years of CNG conversions some converters would use them on light duty vehicles (passenger cars and light truck). These devices invloved a micro switch by the vehicle fuel connector that was activated when the fueling nozzle was connected to the receiptical. The switch would activate a relay that opened the cranking circuit of the vehicle. It prevent those who were distracted from driving away from the pump with the hose still connected to the vehicle.

Hope this helps

Larrycng

[mravi]

Re: CNG Refueling Interlock Device

Thanks Larrycng & CraziFuzzy for your inputs. It is very useful.

I would like to know whether any legislations are in force for refueling interlock device in USA / Europe.

I got one document from internet on West Virginia State Legsialtive Rule
126CSR89 mentioning that all CNG school buses should be fitted with refueling interlock device. Is it really followed in West Virginia? What about other States of USA?

Ravi.

[siai47]

Re: CNG Refueling Interlock Device

Just kind of wondering where this is going. Are we looking for more laws to be written? None of the CNG vehicles I have operated had an interlock to prevent the vehicle from being started with the fueling line attached. For that matter, none of the gasoline or diesel vehicles I have driven had an interlock either--so what's the point? The breakaway devices used in the CNG environment are better at shutting off the fuel flow during a drive-off then a gasoline nozzle shoved into a tank. I don't see any point in adding another interlock into our lives. Just use common sense and pay a little attention when operating any vehicle. As a final point, the only vehicle that I own that has an interlock to prevent starting the vehicle while "fueling" is my electric Rav4. Even with this interlock, more then one member on the Rav4 forum has pulled the charging paddle out of the charge port by letting the vehicle roll away from the charger without starting the motor .

[CraziFuzzy]

Re: CNG Refueling Interlock Device

This is why I believe all stalls at all fueling stations (gasoline, diesel, CNG, electric) should have parking boots that have to be installed on the tire, preferably by a certified parking boot installer.. to prevent such tragedies from happening... ;-)

[larrycng]

Re: CNG Refueling Interlock Device

Why even consider interlocks?

It would be much cheaper, simpler,and practical if the individuals who had a tendency to drive off without disconnecting the fueling hose were to simply remove their head from the dark, smelly place in which it resides

Larrycng

[AVSG]

Re: CNG Refueling Interlock Device

Hi All, This is an interesting subject that we at AVSG have been dealing with for sometime. We own and operate all public CNG stations in the NorthEast. The direct problem we have with "drive-aways" is the cost of repairs. Each nozzle costs approx. $2000. If we're lucky there is no damage to the nozzle, hose, breakaway, or vent line. If there is damage, it costs us time and materials. Because our stations are unmanned we have no way of knowing who caused the damage. In one case, a customer did a cross fill ( pulled up to the wrong side of the island , took the hose from the other side and wrapped it around the dispenser to fill) They then drove away with hose attached. Because the hose was wrapped around the dispenser, the breakaway could not function as designed. End result, it twisted the dispenser off its pad and trashed the whole thing. This guy was nice enough to call and tell us, but refused to admit it was his fault. Our insurance, his insurance and 1yr later and still no dispenser on pad. So drive aways are a problem. From a safety stand point, we have never had a leak do to a drive away.
Now to answer the question, yes there are and have been devices designed to prevent accidental drive aways. We have researched some. Most of them deal with splicing into the starter circuit and disabling it if say the vehicle recepticle rubber cover is not installed on the receptical. Drawbacks to these devices is, should they fail, the vehicle would not start no matter what. So we keep looking and researching. We heard some info from other countries as to how they deal with it. One very simple method, they put the filler under the hood. Hood up , you don't drive away.
Anyway, I don't know if this helps, but it is hopefully more info for thought.

Think Clean, Think Green
AVSG

[cngmike]

Re: CNG Refueling Interlock Device

Well stated. This is a major problem for all station operators. I know of one installer of time fill stations that request the the fleet operator installs interlocks.

[cowboy]

Re: CNG Refueling Interlock Device

cant fix stupid just put the fill recepticle in the middle of the stearing wheel and use a large bulky fill hose so the the fool filling the tank cant get in the car LOL but on the other hand it might just work and that my friends is scary

[Curtis]

Re: CNG Refueling Interlock Device

We have camera's installed that can view the dispenser. Any drive off's will find themselves on the receiving end of a bill they won't want to pay. Compared to the expense of repairs to the station, it might just be the lesser of two evils financially.

[larrycng]

Re: CNG Refueling Interlock Device

As a former student once said, "never under estimate the power of human stupidity."

AVSG, I think you've moved to the hart of the problem; damange to the dispenser. You also have identified the solution for conversion kits; put them under the hood. Under hood is probably the safest location in case of an accident (if there is one). Yes, it is inconvenient.

Bottom line: Since you are dealing with human beings, you can reduce the risk, but you will never solve the problem

Larrycng