Help wanted with gas fittings on boat

RichardS

RichardS

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I've decided to replace the gas hose which runs from the regulator to the cooker. I'm going to need about 8m of suitable hose so feeding it through from the gas locker at the back of the boat is going to be a tricky job and I need to make it as easy as possible.

The current black "rubber" hose is stamped "Accuflex BS3212 1991 / 2 / 6.3 High Pressure LPG March 2006". The external diameter of the pipe is around 16 - 18mm.

The cylinders on the boat are blue butane R907.

This is the fitting which is on each end of the gas pipe:

IMG_7174.JPG


The fitting is stamped "FF 3/8 SAE". I don't think that I'm going to be able to feed the new pipe through with this fitting on each end, although I could obviously feed it through with the fitting on one end only.

My questions are:

I assume that the ID of the pipe I require is 6.3mm (1/4in)? The smallest approved OD I can get will make feeding through easier, of course.

I assume that the end fittings are imperial 3/8 thread and the FF refers to the domed sealing surface?

I won't be able to crimp on the fittings myself, although I could have it done somewhere, but at one end only. However, if I cut off the current fittings will I find a proper spigot inside the pipe so I can simply push it onto the new pipe and secure it with a couple of jubilee clips, or similar, at each end?

If I can't use the existing fittings, what DIY replacements do I need?

Many thanks for any assistance. :)

Richard
 
Unfortunately I don't think you'll get any recommendations for replacement hose.

I know you don't have to comply with the Boat Safety Scheme but the diagrams and requirements are rather a good guide for starters.

https://www.boatsafetyscheme.org/boat-examination-and-certification/boats-with-gas/

Clicking on the link to the 'Chapter 7 of the BSS Examination Checking Procedures', then scrolling to section 7.9.4, you'll see that it's 1m maximum for the flexible hose.

I think any recommendations will be to replace with copper. This should be easy to pull through if pre-fed into some clear hose but will still need supporting at more than just the bulkheads.

[Apologies for deleting previous answer.. Editing the post on the mobile just seems to delete the post instead].
 
It is sometimes possible to feed a 15mm plastic pipe, plumbing, such as water or cistern overflow, then shove 8mm copper through. Simple compression fittings then, with a bayonet type cooker connector or adaptor copper to hose.
 
Martin_J said:
Unfortunately I don't think you'll get any recommendations for replacement hose.
Click to expand...

I'll be able to buy the hose at BES or similar so it's only the confirmation that I required 6.3mm ID and can use the same fittings once I've cut them off.

I'll need to replace the current flexible pipe system, which is fitted to thousands of cats, with a similar replacement as it will not be practical to change over to a completely different architecture when the boat is over 1000 miles away. There is no way that copper pipe could be supported with individual brackets as that would required separating the bridge deck from the hulls so it would just rattle around inside the 3 inch conduit. That's fine for thick rubber hose but I doubt whether it would be acceptable for copper pipe. :(

Richard
 
If only we could get clear solid (overflow) pipe then the gas pipe would remain inspectable throughout it's length.

It would also be good having clear electrical conduit for any cables for a similar reason. :)
 
What kind of gas appliances o you have.

When I fitted out distantshaws I fitted an instant gas water heater that required 3/8 i/d gas tube due to the gas consumption and flow rate through the feed pipe.
 
That's why I said plastic water pipe, it is semi rigid and self supporting, also protects from abrasion. I can see, however, that it might be outside of regs or recommendations.

Sorry, (edit) I mean blue alkathene or similar.
 
Last edited:
Rogershaw said:
What kind of gas appliances o you have.

When I fitted out distantshaws I fitted an instant gas water heater that required 3/8 i/d gas tube due to the gas consumption and flow rate through the feed pipe.
Click to expand...

I had to use 15mm instead of 10mm copper for LPG when the length became too great, about 10mts.
 
The fitting does seem the type where there would be a ribbed spigot for the pipe to go over. Removing the existing crimp part is straightforward but a bit time consuming. I don't thing that you are ment to use jubilee clips on gas hose but the round clips that you close up using a pair of pinches. I think that this is to save damaging the pipe but I have used jubilee clips in the past with no problem.
 
Rogershaw said:
What kind of gas appliances o you have.

When I fitted out distantshaws I fitted an instant gas water heater that required 3/8 i/d gas tube due to the gas consumption and flow rate through the feed pipe.
Click to expand...

We only have a two ring cooker, grill and single oven so probably not a huge throughput unless everything is on at the same time.

I assume that your 3/8 id pipe bigger than the 6.3 mm that I think I have at the moment?

Or are you referring to the 3/8 stamped on the end fitting? I thought this probably referred to the thread of the domed/cone fitting but perhaps I've got this wrong?

Richard
 
RichardS said:
We only have a two ring cooker, grill and single oven so probably not a huge throughput unless everything is on at the same time.

I assume that your 3/8 id pipe bigger than the 6.3 mm that I think I have at the moment?

Or are you referring to the 3/8 stamped on the end fitting? I thought this probably referred to the thread of the domed/cone fitting but perhaps I've got this wrong?

Richard
Click to expand...

3/8 " or 10 mm i/d tube either copper or flexible.

I think most of my fittings are 3/8 BSP.

I agree with you BES is one of the best suppliers in the UK, also in my home town.
 
fisherman said:
That's why I said plastic water pipe, it is semi rigid and self supporting, also protects from abrasion. I can see, however, that it might be outside of regs or recommendations.

Sorry, (edit) I mean blue alkathene or similar.
Click to expand...

Yes, that's what I have. Three long lengths of glassed-in blue plastic pipe about 2 or 3 inch diameter which stretch all the way from the engine compartment at the rear through to the central bridge-deck region. One pipe carries the electric cables and the morse cables, one carries the gas pipe and the other is not used.

I'm not sure that a metal pipe rattling around in there would be a good idea. It wouldn't help if the conduit pipe was clear as you can only see the open ends anyway as the rest is hidden by the boat hull.

Richard
 
Boathook said:
The fitting does seem the type where there would be a ribbed spigot for the pipe to go over. Removing the existing crimp part is straightforward but a bit time consuming. I don't thing that you are ment to use jubilee clips on gas hose but the round clips that you close up using a pair of pinches. I think that this is to save damaging the pipe but I have used jubilee clips in the past with no problem.
Click to expand...

Unfortunately I didn't have my Dremel with me on the boat or I could have removed the fitting before we came home. I can feel that there is something solid inside the rubber pipe which extends beyond the crimped ring but the rubber is so hard with age that it's impossible to feel if it is ribbed and therefore suitable for pushing into a new pipe.

Do you think that my existing pipe is 6.3mm /1/4 in ID? I don't want to buy 8m of pipe and then find when I get down on the boat that the existing fittings are the wrong size.

I'm assuming that the March 2006 date does mean that I really should change this hose? It would obviously be easier to leave it alone but my Wife said that she smelled gas on this last cruise and she's never said that before. I started turning off the cylinder after every use just to be on the safe side. :ambivalence:

Richard
 
I am required to comply with the BSS, our gas pipes (and the pipes taking fuel to the diesel heater) are copper, I think the gas is 8mm. they are each enclosed in a quite close fitting clear plastic pipe (Alkathene?) which does a good job in protecting them from abrasion and impact. When changing the fuel pipes I found it easier to push them through the sleeving before feeding them through the ducting. There is about 1-2 mm, difference between the OD of the pipe and the ID of the sleeve, enough to allow the straightened copper to slip through but tight enough to provide support when bending. The flexible attachment to the cooker is a braided hose with compression fittings but I would be just as happy with a visible gas hose as used at the regulator. The plastic sleeve will harden over time but that should not reduce its protection.
 
I have had 2 sizes of the ribbed spigot for what seemed the same size od pipe. The pipe wall was the difference in the end. One pipe was for high pressure for gas straight from the bottle and the other was low pressure for gas from a regulator. If I was you I would buy the pipe and new fittings just to make sure. Ideally you should have cut the pipe as close as possible to the fitting and taken that home to work on. Can't comment on the date bit, but regardless of what the date means, the pipe if hard, is possibly on its last legs and gas has been smelt so it all needs sorting out.
 
RichardS said:
Yes, that's what I have. Three long lengths of glassed-in blue plastic pipe about 2 or 3 inch diameter which stretch all the way from the engine compartment at the rear through to the central bridge-deck region. One pipe carries the electric cables and the morse cables, one carries the gas pipe and the other is not used.

I'm not sure that a metal pipe rattling around in there would be a good idea. It wouldn't help if the conduit pipe was clear as you can only see the open ends anyway as the rest is hidden by the boat hull.

Richard
Click to expand...

15mm alkathene is only a few mm larger than the copper, gives it proper support, no rattling. It is rigid enough to shove through a very long way
 
fisherman said:
15mm alkathene is only a few mm larger than the copper, gives it proper support, no rattling. It is rigid enough to shove through a very long way
Click to expand...

I misunderstood. I thought that the 15mm you were referring to was the copper gas pipe but you're obviously suggesting sheathing the copper pipe inside 15mm plastic pipe and running that inside the 3 inch plastic conduit.

It's a good thought but I'd rather stick with rubber pipe throughout as the pipe has a very convoluted routing aftwards from the gas locker and then down into the engine compartment and then right angles forward into the conduit before emerging with 3 more right angled turns up into the bridge-deck galley.

Is a long length of copper gas pipe easily bendable to right angles by hand in a confined space? I would then presumably need to fabricate a flexible section to the cooker itself?

I'm not sure that I could do all that in Croatia on the pontoon with tools taken down in the car. I think I'd rather retain the current set-up because once I've done it, it will be easy to replace it every few years as I will know all the fittings and dimensions.

Richard
 
Copper pipe has a specific fitting to be used to go through Bulkheads. The fitting is a compression fitting and prevents any movement.

Steveeasy
 
Your original photo showed a crimped on fitting. This is made using special tool . In reality only a hydraulic hose replacement shop will have one. There is no safe way to reuse fitting.
The brass fitting is most likely a 3/8 bs female thread.
At 2006 the pipe should be replaced, however it is unlikely to have failed, running a flexible pipe through a conduit is not good working practice, 6 or 8 mm malleable copper would be a better replacement however it is apparent you have a challenge.
If a smell of gas, the gas taps on the cooker are most likely problem, failed pipe is further down the list.

Think about a good quality marine gas alarm, if this shows a fault you know you have a gas leek, or leak.
Try gas leak detector fluid on all joints in hose, gas taps on cooker and burner.

Simon
 
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