Long rubber propane lines okay?

[bornyesterday]

I've just read the Practical Sailor article but it doesn't say whether the rat recovered?

Accidental damage and degradation of the hose or pipe and fittings over time are my main concerns.
Happy to agree that copper is more resistant to rat chewing failure but I would argue that it's less resistant to a heavy falling object and that this is far more likely - on my boat.

Hose would be much easier to examine for damage and degradation - on my boat - than the copper that I have. To examine the copper pipe properly I would need to remove it to see the side which faces the hull or the section at the bottom of a locker.
Thorough inspection of hose is relatively easy if it's left long enough to be pulled through lockers etc.

Replacement of hose - on my boat - I could do in half an hour.
I would argue that the difficulty of replacing copper makes its replacement much more likely to be postponed.

Now if I can just convince my insurance company...

[Cheechako]

Hose or copper, it should be fastened to it's surroundings with P clips etc, not left laying and moving around. Preferably under deck etc where things dont rub or fall on it, not in the bilge.

[bornyesterday]

Originally Posted by Cheechako

Hose or copper, it should be fastened to it's surroundings with P clips etc, not left laying and moving around. Preferably under deck etc where things dont rub or fall on it, not in the bilge.

Yep, "adequately supported" in #5 was intended to say the same thing.

A little extra hose length, just enough to allow the hose to be eased away from the structure for periodic inspection, was what I meant in my last post.

Certainly not in the bilge - and I'd think on it some more before I used hose in/through the engine room too.

[MarkSF]

Originally Posted by Dave Lochner

Before installing rubber propane hoses, you might want to read this recent article in Practical Sailor

Please note that the material I linked to is a thermoplastic, not rubber.

Secondly, the article concludes that the explosion was due to the lack of a remote shutoff with leak detector.

Any system, whatever the tubing type, can develop a leak - that's why current standards require a leak detector.

[Jim Cate]

Re the required ID for hose:

If you look at the device that actually admits the gas into the burner, you will see that it has a metering orifice, through which the gas flows. This orifice is tiny... typically less than 0.03 inch diameter for a stove burner. Thus, a very small hose, say 1/4 inch ID is adequate for the supply line.

Cheers,

Jim

[boatpoker]

How to .... Safe Propane Installations on Boats

[gonesail]

Originally Posted by bornyesterday

Hose would be much easier to examine for damage and degradation - on my boat - than the copper that I have

a 3 minute propane leakdown test is recommended for something like this

[ShaunJ]

I replaced my old copper line after it decided to part ways with itself. After a 10 hour sail down the Chesapeake Bay and docking in St Michaels, I thought a warm meal was in order. I opened the valve on the tank and went below to turn on the solenoid. I heard a bit of a whooch, the copper line cracked where it went thru the locker to the rear berth, yes there was a grommet. It filled the boat up pretty quick as i had to run up and shut the valve at the tank off. I replaced it with a Propane approved hose. I don't want that to happen ever again.

[bornyesterday]

Originally Posted by boatpoker

How to .... Safe Propane Installations on Boats

Hi, thanks for the link, he seems to agree that metal is a poor choice:

"5. Fuel Hose - Type approved (UL21) hose or grade K or L annealed copper in one continuous length from the locker to the appliance, must be chafe protected where it passes through bulkheads and secured with clips (plastic). There must be no other connections to this line outside of the locker other than at appliance and for your families sake, don't run it through an engine compartment. The photos in the next section will show why I don't like metal fuel lines approved or not."

[bornyesterday]

Originally Posted by gonesail

a 3 minute propane leakdown test is recommended for something like this

As far as I know propane pressure will only tell you when there's an existing leak? I don't think it will tell you when your copper pipe has corroded to the point where a leak is just waiting for the next big sea - or that your hoses are starting to harden and crack - but aren't leaking just yet.

A high pressure test of the system might find a weakness - but might also cause a weak component to fail some time after such a test - rather than during it.

Surely it's best to be able easily to inspect all parts of your system regularly - that way it's more likely to be fixed in good time isn't it?

[Outwest34au]

When I did my automotive LPG fitting course it included the option of fitting THE CORRECT flexible hose instead of copper. I won't call it rubber hose as it is prolly a composition of nitrile/ silicone/ rubber etc etc.
If I remember correctly the outer sheath of the hose has pin prick holes along it so in the unlikely event of hose failure the gas won't bubble up in quantities under the cover till it pops and releases.

[cal40john]

Originally Posted by bornyesterday

As far as I know propane pressure will only tell you when there's an existing leak? I don't think it will tell you when your copper pipe has corroded to the point where a leak is just waiting for the next big sea - or that your hoses are starting to harden and crack - but aren't leaking just yet.

A high pressure test of the system might find a weakness - but might also cause a weak component to fail some time after such a test - rather than during it.

Surely it's best to be able easily to inspect all parts of your system regularly - that way it's more likely to be fixed in good time isn't it?

Yes it won't predict the future. This is why there is the remote shutoff valve. It is supposed to be off when you're not using the appliance. That way if a rat chews through the line there is essentially no pressure in it and almost no propane leaks into the boat.

When you turn on the valve to use the stove you'll notice the stove won't work and you turn off the shutoff valve, so very little propane gets into the boat.

For a given temperature the pressure in a propane tank is constant while there is propane in the tank. The propane pressure test tests for leaks by first pressurizing the system with the remote shutoff on, looking for loss of pressure with the main valve of the tank off.

[Neeltje]

Originally Posted by bornyesterday

Hi, thanks for the link, he seems to agree that metal is a poor choice:

"5. Fuel Hose - Type approved (UL21) hose or grade K or L annealed copper in one continuous length from the locker to the appliance, must be chafe protected where it passes through bulkheads and secured with clips (plastic). There must be no other connections to this line outside of the locker other than at appliance and for your families sake, don't run it through an engine compartment. The photos in the next section will show why I don't like metal fuel lines approved or not."

He also goes on to say that copper doesn't hold up very well in a marine environment (corrosion, vibrations, etc.), and that the French smoke too much.

Assuming both statements are true (and I can attest to the second one), he makes a very good point for the use of monolithic gas-quality hose.

However, I recently replaced an appliance gas hose that was over 40 years old, yet showed no "visible signs of deterioration" whatsoever, but when I cut it off of it's respective bibs, the only thing that didn't turn to dust was the sheathing...

The point I'm trying to make is that a single run of gas hose is probably the best option on a boat, but that a periodic visual inspection isn't going to tell you what condition it's in on the inside.

The French (them again) require that appliance hoses be systematically replaced (whether they look good or not) every few years, and they even stamp them with a production date to make sure you do if you want to maintain your insurance coverage.

Jacques

[boatpoker]

Originally Posted by Neeltje

The point I'm trying to make is that a single run of gas hose is probably the best option on a boat, but that a periodic visual inspection isn't going to tell you what condition it's in on the inside.

Jacques

I agree a visual inspection will not give you 100% of the story but should still be performed at least annually. Like every other hose on the boat, part of the inspection should involve a good manual squeeze. If the hose has gone hard/brittle it is no longer trustworthy.

Anyone who has cruised in salt water knows that salt gets absolutely everywhere. Over time, the salt air sitting on flexible hose, I believe will draw out the plasticizers that keep the hose flexible and vapour tight. I don't think hose in a salt environment will last nearly as long as in a fresh water environment but I am still a big proponent of hose over pipe ... nothing lasts for ever.

[Canibul]

Well, it's official. I' ve checked with every plumbing supply place in this nation. Nobody even knows what I am talking about. They keep trying to sell me 'yellow hose' at 48 cents a foot. I don't know exactly what their yellow hose is, I looked at a sample and it's just some polyurethane looking stuff, no fabric in it, nothing but the plastic. Thin plastic.

I DO know that whatever I need won't cost forty eight cents a foot in a nation with a 46% import duty.