CNG Questions

[BluePelican]

There are several threads discussing CNG filling adapters and the incompatibility between the traditional 72 CuFt steel tank's 2250psi and the vehicle filling station's 3000psi.

Does anyone know if a 3000 psi CNG tank (similar to an 80 CuFt scuba tank) is readily available? I am assuming the smallest built-in vehicle tanks are too heavy to be portable. Comments from any experts in this field would be appreciated.

Also, does anyone know of a CNG fill or swap location in South or Central Florida? I used to get my tanks filled at a marine shop on the Miami River for $20, but they have gone out of business. Guess I wasn't paying enough or using enough gas.

 

[Bill Roosa]

The tanks are called 20 hour bottles
they have a 3600 psi working pressure, 4000 psi filling and 4800 max assured pressure without bursting. it should be stamped on the top shoulder of the bottle.
filling stations have 3600 and 3200 psi service for the public. Utilities and private can have any pressure but will have the correct and not interchangeable adapter to prevent connecting the wrong filling pressure to the tank.
The tanks are avalable on the internet. $300 / bottle if memory serves

http://www.osh.dol.govt.nz/order/catalogue/archive/gascylinders.pdf
for tank specifics
and
http://www.cngprices.com/station_map.php
for locations.

 

[Steve Dion]

Try this for CNG stations cngnow.com/stations

 

[BluePelican]

Bill & Steve,

Thanks for the input.

When I Google "CNG 20 hour" the only product that comes up is a "20 hour" tank from Corp Brothers which is the standard 2250 psi cylinder. Can you suggest other key words for the 3600 psi tank you are describing?

CngNow.com shows three fill locations in Fort Lauderdale and two in Tampa. I have been unable to locate the FLL locations by their street addresses, the phone numbers go to voice mail, which does not produce a return call. Wondering if they are out of business. The web site seems to be out of date.

I see that postal, county and garbage trucks are going to CNG in this area. Does anyone have any leads on fill stations that may be open to the public?

 

[Chris Patterson]

I'm not trying to be a wise-ass here, I swear not. But if that stuff is that hard to locate, wouldn't an alternative "power" source possibly be in order?
Around here, you can buy propane at the liquor store..

 

[BluePelican]

Chris,

I am just looking for some CNG and was hoping to leave the LPG topic to other threads; but since you brought it up...

If you google "propane boat explosion" and look at the pictures you will see why I would change to electric cooking before installing propane on my boat. Its fine for RVs where a heavier-than-air propane leak will pour out onto the road. Not a good idea where the only place for it to flow is into the bilge to accumulate and wait for the next spark. Sure, there are safety devices, but how much did you pay for that solenoid? The manufacturer guarantees it will work perfectly ... for the next 90 days. How many people regularly test the safety devices?

Just one boater's opinion.

 

[Steve Dion]

Many of these stations are public fill stations. You need to call the number listed on the CNG site and ask them. I also think that some of the places that UPS fills some of their vehicles is also open to the public.

 

[Gunni]

As long as we are considering all of life's many risks, let's consider the latent energy of a 3600 psi gas pressure vessel stored aboard...full of highly combustible gas. If the launch kinetics don't kill you, the explosion surely will.

 

[Richard19068]

As long as we are considering all of life's many risks, let's consider the latent energy of a 3600 psi gas pressure vessel stored aboard...full of highly combustible gas. If the launch kinetics don't kill you, the explosion surely will.

Yes, but hopefully less chance of explosion with the CNG compared to propane.

 

[BluePelican]

Gunni,

Hundreds of 3000psi SCUBA tanks are filled, tossed around in pick-up trucks, car trunks and on boats in the Florida Keys afternoon sun every day. In fact, people even strap them to their backs and jump into the ocean.

Curious minds want to know: What the heck are you doing to your tanks that is causing them to explode???

 

[Gunni]

Gunni,

Hundreds of 3000psi SCUBA tanks are filled, tossed around in pick-up trucks, car trunks and on boats in the Florida Keys afternoon sun every day. In fact, people even strap them to their backs and jump into the ocean.

Curious minds want to know: What the heck are you doing to your tanks that is causing them to explode???

The first tank explosion I saw was in a refill location on the Lower Florida Keys, probably 30 years ago. A worker filling the cascade system somehow jostled the tanks, a valve was broken off and the tank left the building via a block wall and leaving a hole in an adjacent roof. The tank came to rest several hundred yards away in a car. Since that time aluminum tanks have become very popular, there is a well documented history of inferior alloy that has led to many catastrophic failures. While most tank failures occur during filling, there has been an alarming number of aluminum tanks fail while sitting is storage.

In my opinion high pressure vessels (scuba tanks, CNG tanks) are like balloons, you only get so many fills before they go bang. I've seen tanks with expired certs get filled. But those are just full of compressed air. I wouldn't own an old 3,600 psi CNG tank, even if it was certified last year.

 

[Steve Dion]

.....and I guess that we have a host of owners that would not have a propane tank aboard their boat either!

 

[Chris Patterson]

Truth is, I wasn't going to "debate" it at all, as I couldn't care less if people cooked on open fires in the cockpit floor with a black iron kettle. I was working on a boat just YESTERDAY that had three small bottles inside the boat, in a locker, one with a torch still attached. It's an owners acceptability of risk. I've also found many liquor bottles, drugs, high-powered automatic weapons, and various painful looking love toys. Do I care? You've gotta be kidding me.

I just thought that if it was that hard to find...

 

[Stu Jackson]

It seemed only hard for that skipper to find. Steve Dion has solved his issue by building a refill adapter and finding a "gas" station that refills it. If it was me, I'd call the folks that use the stuff as mentioned in an earlier post, and find out where they refill. I've had CNG on our boat (since 1986, we bought it in 1998), have a swap place within 1/4 mile of our marina, and have been generously offered the use of Steve's refill adapter, too. This "where do I find" CNG comes up regularly, and most folks finally find it after a little digging. I don't know if the www.safgas.com website is up anymore, since I haven't had to use it.

I offer that this discussion is not what is the safest fuel to use, but where the OP can find the fuel he has on his boat.

Chris will supply the love toys. And I used to cook on an open fire in the cockpit - it was a small Habatchi!

 

[BluePelican]

Thanks for the input Stu.

I had a look at the safgas.com website. It lists about eight locations in Florida. Most are out of business, and of the remainder, only one knows what CNG is, but does not know where to get it any more.

The industry has to be driven by CNG vehicles and it appears to be a dead concept on the lower East coast. Cannot find a public fill station anywhere.

The only option I have found to this point is to ship cylinders to/from Corp Brothers in Providence, RI.

Still open to input.

 

[BluePelican]

The people at the gas utility companies have proven to be very helpful contacts. However, you have to reach somebody in the engineering department. One girl in the front office clearly showed her exasperation as she patronized this dummy on the phone and explained to me in detail that their gas is delivered to homes and businesses through pipes in the ground to be used for kitchen appliances. It could not be compressed. That was obviously some other kind of gas.

Wise Gas finally returned my call. They will fill a tank for $40 in Fort Lauderdale. wisegasinc.com and go to the marine page for the phone number to arrange a pickup.

Stu and Steve, I see the adapters on EBay and design instructions online, but none of these include pressure regulators. How do you control the fill pressure when you are using a 3000psi pump?

Someone said that I would have to replace my existing regulator if I upgraded to a 3000psi tank. Fact or myth? The difference between 2400 and 3000 does not seem all that large. What pressure are safety rupture disks set for? Anyone? Thanks.

 

[Old Skool Neil]

To further Gunni's post, that's why ALL SCUBA cylinders are required to be visually inspected annually (internally) and hydrostatic tested every 5 years. Aluminum tanks have additional cautions: dissimilar metals corrosion at the valve threads and exposure to high temps (not really that high).

For example, powder coating an aluminum SCUBA tank takes the risk of destroying it. Even the relatively low temp (~ 475° ?) required to bake the powder will alter the strength of the aluminum to result in the picture Gunni provided. I heard of a tank failure on filling that took off the operators legs (side breach) and another that launched through multiple walls (valve neck failure).

The safety of a tank exchange arrangement is this testing is done regularly. If refilling your own via adapter, the fill station operator should be checking for test dates stamped into the neck of the tank.

 

[AustinClarke]

Hello I agree with Steve Dion statement, So please vist cngnow.com

 

[Bill1565]

Thanks for the input Stu. I had a look at the safgas.com website. It lists about eight locations in Florida. Most are out of business, and of the remainder, only one knows what CNG is, but does not know where to get it any more. The industry has to be driven by CNG vehicles and it appears to be a dead concept on the lower East coast. Cannot find a public fill station anywhere. The only option I have found to this point is to ship cylinders to/from Corp Brothers in Providence, RI. Still open to input.

City of Sunrise, fl. Used to fill tanks for the public, by appointment at their municipal CNG station.

 

[BluePelican]

Sunrise Location?

City of Sunrise, fl. Used to fill tanks for the public, by appointment at their municipal CNG station.

Thanks, Bill. Do you have any contact information, or know where the Fill station is located?