Propane leak and ABYC considerations

[dirtniron]

Being new to my 1987 32' Grand Banks in September 2023, last year the 10 lb. propane tank ran out at mid-summer last year. This was the second time of premature run out. Although the consumption seemed excessive there is not much experience with the onboard three-burner stovetop. I again refilled the tank and reinstalled.

A few weeks later, we were undoing the large canvas fly covering the upper seats and steering station. That is when the strong odor of propane was obvious. I then turned off the valve and went into the cabin areas to check for fumes - none. After free air venting, I turned on the tank valve and could smell the propane coming specifically from the diaphragm right at the regulator and not the tank connection. I thence removed this unit and immediately replaced with a brand new one of different and popular manufacture.

The new one is UL listed, the old is not. The old has its assembly rim compressed on using numerous "staking" indentations. It is here for about two inches along the rim that very fine stress cracks could be seen. The leakage could be from here or an internal failure thru the small vent hole. But a leak is a leak, and it is not known if continuous. The new unit is crimped together without stress induced staking.

The old unit is made by NINGBO WANAN model RJ-A. Both are made in China.

Some thoughts:

1. Check your regulator for condition.
2. The C1987 original Grand Banks flybridge under-seat factory propane installation was very effective and kept propane out of the cabin and bilge on several occasions. This also gives thought to why current ABYC requirements are what they are - leaks do happen.
3. I now turn off the propane at the tank when off the vessel for a length of time. We also shut off the electric solenoid valve when stove is not in use.
4. There is no close-to-the-floor bilge fan air venting as found on gasoline powered vessels. The engine room vent fan is mounted high to the ceiling on the port side and is not effective for this low floor venting.
5. I would recommend the installation of a "gas vapor detector" system with two sensors - one below the propane stove and another in the low spot of the bilge, considering bulkhead structure locations.

End

 

[TJM]

I have a Propane fireplace and have many safe guards. Propane sniffers (replaced every 3 years), Carbon Monoxide monitors and smoke detectors. ABYC A-1 Standard is worth the read and compliance.
Xintex-Fireboy makes a few solenoid systems that automatically turn off the Propane fuel source if propane or CO is detected over a certain PPM. I test mine monthly with butane.

 

[tiltrider1]

Oh, that’s very scary, the lack of adequate flammable fume detection around the propane bottle. I can’t imagine not having an auto shut off device with a sensor under the stove and at the base of the propane bottle. Hope you take your own advice on safety sensors.

Propane is heavier than air, the stink to help you discover a gas leak is not heavier than air. Meaning the propane could be in the bilge why the stink is in the flybridge.

 

[Portage_Bay]

Interesting. Something to keep in mind regarding safety with propane. Thank you.

Propane is heavier than air, the stink to help you discover a gas leak is not heavier than air. Meaning the propane could be in the bilge why the stink is in the flybridge.

 

[Comodave]

You should periodically check that the system is holding pressure by pressurizing it and letting it sit and then come back and see that the pressure hasn’t leaked off. There is likely a spec as to the time and pressure but I have never had propane on any of my boats so I don’t know what it is.

 

[Clark]

Leaking regulator failure is common and I've had to replace several on my boats. I don't know why, but all of them seem to be made of material the are prone to rust and corrosion.

 

[BruceK]

Perhaps the apparatus extracting propane/LPG from the tanks has not been checked recently. Suggest you check the tank(?bottle) valve and tank itself. Here at least, these come with a compliance expiry date after which they will not be refilled but it can be extended after testing ok.

 

[Portage_Bay]

I was told by my surveyor that the time to check for leak down is 5 minutes. For what it's worth the leak down in my system is days. I don't think I'd be comfortable with 5 minutes.

You should periodically check that the system is holding pressure by pressurizing it and letting it sit and then come back and see that the pressure hasn’t leaked off. There is likely a spec as to the time and pressure but I have never had propane on any of my boats so I don’t know what it is.

 

[DDW]

Hoses too - I've had two hoses leak at the crimp on the boat, and two at home on the BBQ. These weren't old, less than 2 years. Made In China....

 

[jgwinks]

I've had a couple "marine grade" regulators fail. The cheap backyard BBQ type from the hardware store seem to last as long or longer, I quit buying the expensive ones. I do a leakdown test periodically, at least when changing tanks (I carry two) or more often if I think of it.

 

[Bmarler]

Abyc recommendations do indeed specify the inclusion of a pressure gauge on the system. A leaky regulator will show up pretty quickly when you shut the tank valve.

 

[Fleming]

The old Grand Banks with their under-flybridge seat propane compartments are notorious for not being ABYC compliant. Tanks should be in a sealed compartment, with no other items stored with them, with a top opening lid with a gasket seal. There should be only one opening, at the bottom and vented overboard. There should be a pressure gauge and the line from propane locker to stove should be continuous with no breaks or valves in between.
You aren't required to have an electric solenoid shut off, but it's a really good idea.

 

[jgwinks]

When I converted my motor yacht to propane I looked at how so many have the tanks up under the fly bridge, I knew that was a no-no so I put the locker out on the swim platform. Takes up some space but I think is easier to access than up on the bridge.

 

[Comodave]

When I converted my motor yacht to propane I looked at how so many have the tanks up under the fly bridge, I knew that was a no-no so I put the locker out on the swim platform. Takes up some space but I think is easier to access than up on the bridge.

And much safer too…

 

[dirtniron]

Here are some additional thoughts on making the mid 1980's Grand Banks 32-foot trawlers propane safer and leaning towards the current ABYC recommendations.:

1. The port side flybridge seating is essential a "propane locker" designed decades ago.

2. The copper feed line to the salon stove may not be easily replaced with the current lines that have large diameter 3/8" fittings.

3. There is an access hole, about 4 inches above the floor, that leads into the inner flybridge port structure, on the forward port side. This should be taped off to make this "locker" sealed and allow any propane leakage to vent in other locations.

4. There are two primary areas under the forward steering station that could allow any fumes that propagate there to move down to the salon (The main steering and electrics piping and starboard windshield wash plumbing) Seal these areas up.

5. Add a floor level 3/4-inch drain hole to outside this flybridge locker. location where there is already a cut in the inner structure. Cover the outside with a metal "clamshell", venting aft. Above this area and slightly forward is a factory installed larger vent to the outside, but it is about 7 inches above the flooring and not ideal for propane venting.

6. With number "5", above, the salon sliding windows below and near this new venting should be kept closed. One technique would be to drop a small diameter wood dowel cut to length into the window channel to prevent opening or vibrating open. The vessel has plenty of other windows that function.

7. I use the "10 Pound" steel propane tank kept where it was designed to be. IF a surveyor did not accept the above and/or an insurance company did not accept same, a tightly filling fiberglass "locker" could be fabricated that fits the tank with an extension made for the extended gauge-regulator- electric valve units. At the locker bottom a 1/2" ID drain line could be plumbed to the vent in "5", above. Enough room is available on top and below the seat base for a flat lid and secured to the 'locker". A large drawback would be the tank valve is not readily accessible to shut off the tank as I originally described at the beginning of my post.

Bottom line for me is I feel the original G.B. design and installation is safe. But the above makes it "safer" and that's what is comfortable for us.

End.

 

[SteveK]

HERE is a 2022 thread with answers, if the rules are still the same.
@Steve DAntonio explains

 

[dirtniron]

HERE is a 2022 thread with answers, if the rules are still the same.
@Steve DAntonio explains

Thank you. I looked at and copied that previous thread you mention. I am thus comfortable with what I now have as described above..

Geoffrey