CNG Refilling

[Guenter Retkowski]

100cu ft , really ?

Fortunately the actuarial odds usually are in our favor (until there not).Discussions with insurance underwriters (regarding recent surveys) indicated that they do not
"grandfather" systems like CNG or LPG. There is no pleasure in delivering negative survey findings.

Dedicated locker is required when tank capacity is >100cu ft. There are separate standards for devices using cylinders <16oz.
22.7.4.7 For CNG installations that include an attached combined capacity of greater than 100 cubic feet (2.8 cubic meters), the cylinders, and connected valves, regulating equipment, and safety devices shall be located on the exterior of the boat where escaping gases can flow directly into the atmosphere outside the boat, or
22.7.4.7.1 the cylinders and connected devices shall be installed in a dedicated locker.
22.7.4.7.1.1 Dedicated lockers shall be vapor tight to the hull interior, and
22.7.4.7.1.1.1 vented to the open atmosphere outside the boat, and
22.7.4.7.1.1.2 constructed of or lined with corrosion resistant materials, and
22.7.4.7.1.1.3 equipped with a means to discharge incidental accumulated water.
22.7.4.7.1.2 Dedicated lockers shall be equipped with a cover that
22.7.4.7.1.2.1 opens directly to the atmosphere, and
22.7.4.7.1.2.2 latches tightly, and
22.7.4.7.1.2.3 is capable of being quickly and conveniently opened without tools, and for operating the cylinder valves, testing the system for leakage, and viewing the pressure gauge.

I provide my survey clients with the text of the ABYC standard relevant to the survey discovered deficiency.

FYI ABYC membership starts now at $255.00 per year.

Sorry for getting in late on this conversation, but I am in the middle of thinking whether to convert my CNG system on my 1986 C34 into propane or to build the CNG adapter. Here on Lake Michigan absolutely nobody fills those tanks anymore - Larsen Marine in Chicago has build a nice monopoly with an exchange program - hand your empty tank in and get a filled one back. For ONLY $120 !!! So, CNG adapter it is.

Also, the ABYC directive cited here does not apply to pleasure sailors. Do the math. >100cu ft. is huge ! The CNG tank on my Catalina is a 10 liter tank, identical size to a scuba tank. 10 liters = 0.01 Cu m = 0.35 Cu ft. , therefore far , far below the directive's measure.

My tank lasts me about 1 season ( which is short up here).

BTW, my surveyor tried to talk me into a vented locker and a switched safety valve years ago - just like for a propane set up. But the boat industry called CNG safe gas for a reason back then. All of those things don't need to be done. Except, the tank needs to be pressure tested ( just like scuba tanks) in , I believe, 5 year intervals. Too bad it didn't hold up - propane has a much better infrastructure in the US. But other than that......

 

[Guenter Retkowski]

Re: 100cu ft , really ?

I might add - at 2,500 PSI this tank capacity is at 88.28 cu ft of CNG and still under the 100 cu ft

 

[Sailor_Jeff]

Guenter, thanks for the post. It never occurred to me to do the math.... Thanks again.

I might add - at 2,500 PSI this tank capacity is at 88.28 cu ft of CNG and still under the 100 cu ft

 

[Guenter Retkowski]

Guenter, thanks for the post. It never occurred to me to do the math.... Thanks again.

Sorry Jeff, didn't intend to sound like a smarta$$ - I am new to the forum and didn't see page 2 and 3 - other people addressed this long before me as I see now.

The important thing to know is - we CNG users don't need to modify our boats by adding vented lockers, safety shut off valves and such - that's for the propane folks. When Catalina and Hunter build boats in the 80s, the ABYC was around back then and wouldn't have approved a set up as it was , if it would have not met their directives. There are thousands of these boats built that way.

I will build me one of those adapters instead of converting my perfectly fine gas stove and CNG set up - and become independent of those handful of Marina's in the US that take advantage of their customers.

 

[Stu Jackson]

CNG finis

1 ...........There are thousands of these boats built that way.

2 I will build me one of those adapters instead of converting my perfectly fine gas stove and CNG set up - and become independent of those handful of Marina's in the US that take advantage of their customers.

Guenter,

1 Yup, mine's one of them, and Guenter's C34 is actually older than mine! :dance::dance::dance:

2 Good idea. When you're ever out this way, come by for a ride and we'll go meet up with Steve and refill our CNG tanks!!!

 

[Guenter Retkowski]

Guenter,

1 Yup, mine's one of them, and Guenter's C34 is actually older than mine! :dance::dance::dance:

2 Good idea. When you're ever out this way, come by for a ride and we'll go meet up with Steve and refill our CNG tanks!!!

I will take you up on that, Stu ! Thanks

 

[Enoosh]

We keep our CNG in scuba tanks and we need to refill but the nozzle at the refilling station doesn't fit. Need suggestions for an adaptor.

I saw an adapter on ebay if you look up CNG fill adapter but although it is with the CGA-350 threads I dont know what threads are on your scuba tanks