What to do with my propane solenoid?

[raahell]

Hi Everyone,

Still ticking away at my steel boat refit. The "steel" part is going well. Exterior hull refit completed and boat is in water and completely dry. Small miracle considering how many things got replaced or changed below the waterline. Never been so nervous watching a boat get launched!

Now working on inside hull plating, ribs, stringers etc. While I'm deep in the bilges I'm also tackling other aspects of the boat I don't like, including the propane system. Hence this post:

The existing system starts with a stern rail mounted propane bottle with hose that goes to an un-ventilated stern quarter lazerette where the solenoid is located . From there the gas runs along copper lines to the gas stove in the galley. The lazerrette BTW is not sealed from the liveable space. I know, lots of things not to like about this set-up and it's already flagged in PO's surveys.

I've removed all the copper lines and now have a 35' marine propane hose to install. My question, however, is about the solenoid. ABYC regs and common sense dictate that if placed inside the boat it has to be in a space ventilated to outside. Or mounted outside. Looking for advice on where and how to set up the solenoid.

Here's my options as I see it:

1)- Purchase a sealed box for the solenoid, install inside lazerette and plumb it to the transom bulkhead so that it ventilates to exterior. Wires and plumbing also have to plumbed to this box and sealed properly so that gas will not escape to boat's interior. Advantages: everything's protected from the elements and from, getting knocked. Cleanest solution aesthetically. Disadvantage: Chances of seals failing and creating same problem as I have now. Not sure if this will satisfy ABYC/surveyor(??)

2) - Purchase a sealed box, install on exterior of transom bulkhead (boat has a sugar scoop stern so box would be protected from collision and easy to get at). Plumb hose and wiring through gland fittings to box, preferably with glands hidden inside/behind the box to minimize exposure of glands/wiring. Put hole in bottom of box (with screen) to allow it to ventilate. (Advantages:Everything's outside and easier to service. If glands/box seal fails, gas will still vent to outside. Disadvantages: Another box/fitting on transom. More holes to be made in steel plating.

3) - Mount the solenoid on the stern rail, near the bottle. Fit glands on deck or on transom for hose and wiring to lead up to solenoid, probably with some sort of raceway to shield them. Leave solenoid exposed or perhaps sew up a fabric cover to limit exposure. Advantages: Probably least expensive (I sew my own stuff and have lots of scrap to make this for free). Super easy to get at solenoid/wiring/hose. Disadvantages: Least amount of protection from elements/knocks. More visible gear at transom and on rails.

So, any advice out there? Do you have your own solutions that your proud of and willing to share? Does anyone know of any hardware (boxes, glands, hose and wiring routing/shielding products, thru-bulkhead gas fittings, etc. that you think could help make this job secure and satisfy a future surveyor?

Thanks in advance for your guidance.

Going to the boat tomorrow so can post a pic of the transom/gas bottle area if that's needed to get a bearing on the problem.

BTW, boat is located in Canada so please keep this in mind if suggesting sources.

[tkeithlu]

Sure. Put the solenoid in the box with the propane bottle. Vent the box bottom overboard (I like the transom idea). The only thing that comes out of the box is the 35' hose to the stove and the wire to the solenoid. No junctions in the hose after it leaves the box. If you have two uses for propane, then it's two hoses coming out of the box.

Suggestion, maybe not ABYC required (I don't have the book with me): No hose between the bottle and the solenoid - hard plumb it with pipe threads and Teflon tape.

The solenoid is meant to shut down the system. If it is separated from the bottle, then there are all those additional possible places for a pop and a flood of propane.

[wsmurdoch]

Just mount everything outside like this commercial rail mount.



https://www.suremarineservice.com/Ga...cket-Assembly/

[Bill O]

We made our own f/g propane tank holder w/room inside for the regulator, gauge and shut off solenoid. It is sized for 20# tanks, but could easily be made for smaller ones. Here is the link to our write up.

If you had to have the solenoid outside, a box could be good to extend the solenoid life to keep saltwater away from it. On our last delivery I had to change out the propane solenoid that failed due to saltwater intrusion in a "sealed" deck locker. Apparently the deck/propane locker seal failed, even though it was a fairly new boat.

Since the solenoids tend to get very warm/hot, the downside of a sealed box could be from trapped heat. Not sure which would be worst, saltwater exposure or trapped heat.

[Tomodore]

Years ago I Believe it was Maine Sail that recommended a solenoid that was lower power and lower heat, kind of a win/win. Anyone remember details ?

[wsmurdoch]

I don't know about Maine Sail, but a couple of years ago I wrote this in an older thread.

https://www.cruisersforum.com/forums...nt-201760.html

The large capacitor / resistor set up still works. The capacitor gives the jolt to open the valve, and the resistor restricts the current after the valve is open. All the electronic bits are inside a waterproof single outlet box.

[Orion Jim]

Originally Posted by wsmurdoch

Just mount everything outside like this commercial rail mount.



https://www.suremarineservice.com/Ga...cket-Assembly/

This is what I’ve had for about 14 years. I have a Sunbrella cover over it for looks and protection.

[Bill O]

Originally Posted by wsmurdoch

I don't know about Maine Sail, but a couple of years ago I wrote this in an older thread.

https://www.cruisersforum.com/forums...nt-201760.html

The large capacitor / resistor set up still works. The capacitor gives the jolt to open the valve, and the resistor restricts the current after the valve is open. All the electronic bits are inside a waterproof single outlet box.

Very nice!

[Jamme]

Originally Posted by Orion Jim

This is what I’ve had for about 14 years. I have a Sunbrella cover over it for looks and protection.

Beautiful boat BTW!

[RaymondR]

The way those solenoids are constructed is that all the bits in contact with the gas is sealed inside a metal housing with a pressure rating of the pressure rating of the valve. As a result the most likely failure point if you left it in the lazarete is likely to be either a loose screwed connection or the hoses connected to it.

[Tomodore]

Important to have solenoid or other means meet hazardous location standards for ignition or rather lack of ignition. Propane, gasoline and carbon monoxide are 3 items not to take short cuts with.

[Bill O]

Originally Posted by RaymondR

The way those solenoids are constructed is that all the bits in contact with the gas is sealed inside a metal housing with a pressure rating of the pressure rating of the valve. As a result the most likely failure point if you left it in the lazarete is likely to be either a loose screwed connection or the hoses connected to it.

Will add they can fill w/water and not work. This is what happened to the one I replaced during a delivery. Never seen that happen before, but now I can't say that again.

[RaymondR]

Originally Posted by Tomodore

Important to have solenoid or other means meet hazardous location standards for ignition or rather lack of ignition. Propane, gasoline and carbon monoxide are 3 items not to take short cuts with.

True but combustion requires oxygen, fuel and ignition source.

In the locker both oxygen from the atmosphere, fuel from leaking butane in the locker and the possible leaks from connections, holed diaphragms in regulators, stem glands of valves etc are numerous, and ignition source ie the electrical components of the solenoid coil are all possibly present,

However, if the locker containing all the possible, and probable, fuel source is isolated from the probable ignition source as would be the case with the solenoid valve in the lazarette then combustion is far less probable.

However there are often local standards which, if one wants to comply with because a gas certificate may be required by regulatory authorities and insurers one may feel a need to comply with.

[nuku34]

I’ve used LPG with an externally mounted tank (both steel and alloy) on the pushpit for many years on 4 different yachts. Always had the solenoid attached directly to the regulator. Hose from solenoid and wires to it go through glands in the deck. I’ve never bothered to try and keep water off the solenoid; it just is not really practical; any “box” will eventually leak. The steel covering of the coil eventually rusts out and the whole unit needs replacing. I found they last for several years and I always carry a spare. For me its just a mainenance issue, no big deal.

Having the tank on the pushpit has also never been a problem. We had a spare tank mounted on one of the “fanny bars” around the mast on our 12m steel “Joshua” ketch.
The steel tanks eventually rust and/or get out of test date, but again that’s just a maintenance issue. Here in NZ, new steel tanks are dead cheap and they are certified for 10 years. Re-certification/testing is more costly than replacing. Expensive alloy tanks last longer, but they also need to be tested and that may not be cost effective.

KISS (keep it simple sailor)

[raahell]

Thanks for the advice, everyone. Pic shows what I eventually came up with.

I bought a waterproof 4" x 4" electrical box and mounted it to a SS plate mounted to the stern rail (top left of pic). Drilled 3 x 3/4" dia holes in the box, for the propane hose in and out and for the electrical gland. Ran propane hose through a large gland in the deck and another gland in a 2nd hole for electrical conduit, for the solenoid wires (bottom right of pic).

The solenoid is floating inside the box. The hoses going in and out of the box keep it in position. I've caulked between the box and the hoses to seal it up.

I added a large number of very small diameter (1/16") holes in the bottom of the box to allow for venting propane overboard in case of leak, and to allow any water that manages to get inside, to drain.

The final important detail is that I also caulked the interior of the wire gland on the box, as otherwise it would be possible for escaping propane to make its way back down the electrical conduit into the vessel. Didn't think of that possibility until I was completing the install.

Other than the gland for the propane hose (purchased at a chandlery), I got everything else from Home Depot for just a few $$. This is all exterior rated stuff so should last for some time.