How do you fill a CNG cylinder

Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
You will want to understand what pressures your tanks are rated to and what the filling station provides. There are older CNG bottles that are only "certified" to 2600 PSI (the old standard) and all filling stations are now 3000+ (3000 and 3600 if memory serves) psi. The certified pressure is stamped on the bottle.
With all that said and noting that I've been in several war zones and have an engineering degree..(stress is something a little more exciting than filling bottles with flammable gasses)... the actual bursting pressure, filling pressures of these bottles does not change with certification. Those are PHYSICAL properties of the bottle that do change over time with corrosion and the number of times you fill them (pressure stress). The date of last testing for cert is also on the bottle.
I'd recommend you do a little homework BEFORE you attempt to fill YOUR bottles with CNG
The pressures encountered when filling my 2004 cert 2600 psi 20 hour bottles was really close to 4000 psi. That goes down as the bottle cools after filling to something like 3000 psi which is still over the cert rating. My bottles where in good condition and came to me with 3000 psi in them so my stress level was only moderate when I eyeballed the 4000 psi filling pressure. I had to go to an older filling station that had the 3000 psi pumps. Now if you hooked up a 2600 psi cert bottle to a 3600 psi pump..........That might result in some elevated level of stress for yourself and those nearby.
FWIW
 
Oct 1, 2008
12
Hunter 40.5 Port Charlotte
I am in FL, does anyone have a location for filling tanks. My Tampa vendor is gone.
 
Mar 5, 2012
152
Hunter 37-cutter Saint Augustine
BUY. lpg its cheaper and safe, how would you like a bottle go off on a rough sea. plus it hard to get. it a no brainer
 
Mar 11, 2009
199
Hunter 40 Saint John
Lyel:

The filling station nozzle plugs into the filling adaptor. You just push the botton and it is filled. Of course the valve needs to be open.
$8 DOllars, I live in SAint John New Brunswick, Canada, I have no choice but to go to Southwest HArbour Maine, to get a bottle and that cost me 80 bucks US for the small bottle....
 
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Oct 1, 2008
12
Hunter 40.5 Port Charlotte
More research on where to fill CNG tanks in FL. There appears to be only one location in FL - Ft Pierce Utility.
 
Oct 1, 2008
12
Hunter 40.5 Port Charlotte
Google shows there are loads of CNG stations. Many are private, many are listed and don't exist and others are open to the public for vehicles systems, not for tanks. If anyone knows of a specific location to fill a cng tank - let me know
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
There is one near BWI Airport, so maybe same thing in your area? I think they run those baggage carts or such.
 

nfg2u

.
Feb 13, 2016
92
Hunter Legend 35.5 Fort Pierce
Ft. Pierce Gas and Electric no longer fills CNG tanks, their machine broke and they are not replacing. I just had my two tanks Hydro tested. Bought an adapter and will be filling at Opis Energy. Opis is a public CNG auto fill station that takes a Credit Card at the pump. If you don't have an adapter give them a call. They will meet you at the pump with one.

Opis Energy
1126 Hammondville Rd
Pompano Beach FL33069
(954) 636-4291

Hydro tested my bottles for $50 each.

Hydro-Stat Inc.
1111 SW 1st Way
Deerfield Beach FL 33441
(954) 428-7677

Steve
 
Jun 11, 2004
1,621
Oday 31 Redondo Beach
Ft. Pierce Gas and Electric no longer fills CNG tanks, their machine broke and they are not replacing. I just had my two tanks Hydro tested. Bought an adapter and will be filling at Opis Energy. Opis is a public CNG auto fill station that takes a Credit Card at the pump. If you don't have an adapter give them a call. They will meet you at the pump with one.
Steve
Steve, where did you buy your adapter?
 
Oct 2, 2008
3,807
Pearson/ 530 Strafford, NH
Ft. Pierce Gas and Electric no longer fills CNG tanks, their machine broke and they are not replacing. I just had my two tanks Hydro tested. Bought an adapter and will be filling at Opis Energy. Opis is a public CNG auto fill station that takes a Credit Card at the pump. If you don't have an adapter give them a call. They will meet you at the pump with one.

Opis Energy
1126 Hammondville Rd
Pompano Beach FL33069
(954) 636-4291

Hydro tested my bottles for $50 each.

Hydro-Stat Inc.
1111 SW 1st Way
Deerfield Beach FL 33441
(954) 428-7677

Steve
Thanks Steve

All U Get
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
No it doesn't; propane leaks into the propane locker, which is vented overboard.
Not necessarily true, jviss. The point is, it will settle to the lowest place it can find, the worst being the bilge/cabin and go ka-boom. Watch the movie Masquerade.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Not necessarily true, jviss. The point is, it will settle to the lowest place it can find, the worst being the bilge/cabin and go ka-boom. Watch the movie Masquerade.
In a poorly designed, improperly installed, defective or otherwise poor or dangerous installation, propane can settle in the bilge, sure. Do you realize that the vast majority of boats with ranges use propane? A leaky tank or tank whip will leak into the propane locker, which is vented overboard, not into the bilge. My solenoid is only energized when the range is in use. I test if often, by turning off the solenoid before turning off the burner. I have a propane sniffer. All very safe when properly maintained. This is true of any system. That kid in the video, filling the CNG tank, sent chills up my spine. I would much rather deal with a propane leak than have to try to fill a 3000 psi CNG tank at a self-service station with my own adapter, and quickly overpressure it by 17% as that knucklehead did. CNG tanks do explode. At a self-service station, who's making sure the tank is in-hydro, with no external signs of corrosion or other damage?

I'll pass on the movie, thanks anyway.