Gas pipes in bilge/floorspace

[Positively4thStreet]

Hi,

 

I have another question regards lpg pipes on board; is it allowable to run an LPG line under the floor (fully inspectable and securely afixed, of course) to reach a kitchen island. Though the BSS guidelines that I have read through do not explicitly state that it is not allowed, I am under the impression that it would be picked up under one of the more ambiguous criterea concerning the avoidance of explosions and the like (which is obviously useful) because of the obvious issues with leaks filling the bilge and the like. But recently I have seen a photograph of a new build widebeam with a gas hob on a kitchen island and no overhead pipework so I am assuming it is run beneath the flooring. Does anyone have any knowledge on whether I can run a gas line under the floor.

 

Any help is greatly appreciated.

 

Cheers

 

Gregg

[ditchcrawler]

As far as the BBS is concerned I suggest you email them with full details of your proposals. they will answer you and if they say yes you will have the paperwork to show any future inspector who may think it wrong.

[Paul C]

Yes underfloor is fine. The entire pipe pathway must be accessible for inspection - if there is a straight run hidden, its assumed to be unbroken (and will pass); if a corner is hidden, its not assumed to be unbroken, and will fail based on incomplete inspection.

[David Mack]

A leaking pipe in the bilge poses no more of an explosion risk than a leaking pipe higher up.

 

The current BSS requirements for private boats (here - Section 7.8) do not prohibit pipes through bilges, as long as you meet the other requirements for pipes to be securely fixed, protected when passing through bulkheads, joints to be inspectable etc.

[Tiggs]

A leaking pipe in the bilge poses no more of an explosion risk than a leaking pipe higher up.

 

I think that they do. There is a good chance of smelling the leak if the pipes run in the traditional place just below the gunnels. If the pipe was under the floor the bilge could fill with gas before you had a chance to smell it.

 

I agree with what you say about the BSS but personally I would not put gas pipes under the floor with taking further precautions in the detailed design - i.e. prevent any leak getting into the bilge.

[ditchcrawler]

2 question

1, How many boats have exploded due to a gas leak in a length of copper pipe that is correctly clipped with no joints.

2, How many boats have exploded due to gas leaks while changing cylinders?

[alan_fincher]

...........if there is a straight run hidden, its assumed to be unbroken (and will pass);................

 

Is that now explicitly stated somewhere, because I don't recall ever seeing that.

 

I thought it all had to be so that it could be inspected if they ask to, or has that changed?

[FadeToScarlet]

My old boat had one, running under the floor to where there was previously a gas fridge.

 

Two surveyors, and two BSS inspectors, didn't spot it! Neither did I, until I removed the electric fridge from in front of it.

 

Very dodgy indeed.

[Paul C]

 

Is that now explicitly stated somewhere, because I don't recall ever seeing that.

 

I thought it all had to be so that it could be inspected if they ask to, or has that changed?

 

No its not but when I had my BSS done, the inspector verbally explained it - in fact he failed the boat first time, it needed work doing (other stuff) and also it needed a bunch of stuff removed to reveal the corners of the gas pipework. He wasn't worried about looking at every inch of the straight runs though.

[alan_fincher]

 

No its not but when I had my BSS done, the inspector verbally explained it - in fact he failed the boat first time, it needed work doing (other stuff) and also it needed a bunch of stuff removed to reveal the corners of the gas pipework. He wasn't worried about looking at every inch of the straight runs though.

 

OK, but I believe you are into the territory of interpretation by an individual inspector, rather than a hard and fast relaxing of what the book actually says.

 

A bit like whether properly labelled flexible spill rails are allowed on something like a BMC engine - it is sometimes necessary to take such matters to the BSS office for a verdict if different inspectors have different interpretations.

[blackrose]

 

Is that now explicitly stated somewhere, because I don't recall ever seeing that.

 

I thought it all had to be so that it could be inspected if they ask to, or has that changed?

 

I once had an inspector say this to me - but only because I told him it was an unbroken pipe run an he couldn't be bothered to get on his hands and knees and look inside a length of cupboards. I don't believe it's officially stated anywhere in the BSS guide.

[MtB]

If this is a new boat you'll need to comply with BS5482-2005 Part 3, which says gas pipes must be fitted as high as 'practicable' in a boat, or words to that effect.

 

 

 

(Edit to correct a worm or two.)

Edited November 9, 2015 by Mike the Boilerman

[David Mack]

If this is a new boat you'll need to comply with BS5482-2005 Part 3, which says gas pipes must be fitted as high as 'practicable' in a boat, or words to that effect.

 

 

 

(Edit to correct a worm or two.)

 

One could argue that means the gas pipes must run at ceiling level, rather than under the gunwale where they usually are...

[nicknorman]

If this is a new boat you'll need to comply with BS5482-2005 Part 3, which says gas pipes must be fitted as high as 'practicable' in a boat, or words to that effect.

 

What's the thinking behind that?

[Murflynn]

................... in the case of exposed pipes, presumably to minimise the risk of being accidentally damaged

[cuthound]

................... in the case of exposed pipes, presumably to minimise the risk of being accidentally damaged

Not if you put them on the roof and then catch them on a low bridge , or do they say inside of the boat...

[Tony Brooks]

What's the thinking behind that?

 

I think that was the wording in the Old Thames Conservancy Launch Regulations.

 

When we bought boats from the Broads we often had to re pipe the gas at high level. On wooden boats this was usually on the outside of the cabin side and high up. On GRP ones at gunwale level or along the roof - cabin side join.

 

We got more than one Broads boat with the gas running under the floor in long "troughs" made from routed wood and caped with a nailed on wooden cover. More than one had perforated or near perforated pipes with many tiny holes or very near hole type pits. That was enough to persuade me that gas pipes under the floor are not a good idea.

 

As far as the question goes I agree that a verdict is required from the BSS office but I see only two options. Under the floor as stated but with a removable floor section for inspection or across the roof and down. The latter would require a vertical support that may or may not be aesthetically pleasing. If that support included (say) a couple of shelves and a cup/mug rack it could look good and be useful. Otherwise I suspect I would go for the under floor route but would inspect the pipe at least annually.

Edited November 10, 2015 by Tony Brooks

[MtB]

What's the thinking behind that?

 

A leak is more likely to be smelled if the pipework is high in the boat.

 

A leak is almost certain not to be smelled if the pipework is under the floor.

 

Running pipes under the gunwales was a compromise initially IIRC. Now it's considered normal but I doubt a new boat would get an RCD with pipes under the floor, even if a BSS bod finds it acceptable.

[Murflynn]

 

I doubt a new boat would get an RCD with pipes under the floor, even if a BSS bod finds it acceptable.

you mean that a self-certifying builder would not allow himself to do it?

[ditchcrawler]

Now it's considered normal but I doubt a new boat would get an RCD with pipes under the floor, even if a BSS bod finds it acceptable.

Of course it would, the same people who design and fit the boat are the ones who says it complies with the RCD requirements. The same way as you see new Narrowboats with Navigation Lights that don't comply with the CoL regs. The RCD doesn't call for Nav Lights, but if fitted they must comply with the CoL regs.

[nicknorman]

A leak is more likely to be smelled if the pipework is high in the boat.

 

A leak is almost certain not to be smelled if the pipework is under the floor.

I suppose so, but all that presumes someone is on board to smell it. So there is only a gain in safety if a leak occurs whilst the boat is occupied. If it's not occupied but say the owner comes back, opens the door with a fag in his mouth etc, it's going to be just as boom-tastic as it would have been of the pipes were under the floor.

[Paul C]

Surely the advantage of a higher-up pipe being easier to detect a leak is minimal/non existant. The gas is heavier than air, and the pipework is typically enclosed behing panels/units etc. The gas wouldn't leach through the gaps in the panels with any urgency, it would flow down the back of the panel and settle in the bilge. This would apply even if the gas pipe was at roof level behind a panel. Only if it were running centrally down the boat would there be a remote chance of significantly higher amount of gas leaking from behind the panels and into a main cabin airspace to be detectable by nose.

 

To better explain it, imagine it was a water pipe instead of a gas pipe, and think of how detectable it would be if it sprung a leak. Low or high, behind a panel, and its in its own cosy little environment.

[MtB]

Nick asked what the thinking was behind it. I'm just answering the question about the thinking behind the reg, not asserting the thinking is correct.

 

I'd still be very wary about running a gas pipe through the bilges. I think I'd only do it if I could use a single continuous length of pipe with no joints. And even then I'd recommend the whole length be accessible for inspection, if only so a BSS bod could satify himself there really were no joints!

[ditchcrawler]

Nick asked what the thinking was behind it. I'm just answering the question about the thinking behind the reg, not asserting the thinking is correct.

 

I'd still be very wary about running a gas pipe through the bilges. I think I'd only do it if I could use a single continuous length of pipe with no joints. And even then I'd recommend the whole length be accessible for inspection, if only so a BSS bod could satify himself there really were no joints!

Would a trap hole in the floor and mirror mounted below the board to reflect the length of the pipe suffice the inspection requirement?

[Paul C]

AIUI the OP is looking to fit a kitchen island with a cooker on it. So, the gas pipe could be routed in a "normal" place for example just under the gunnel, then vertically descend along the wall behind a removeable panel; then horizontally along the floor (another removeable panel reveals the corners and the floor section of pipe) then into the island (another removeable panel reveals it; or a cupboard door is opened and the gas pipe is viewable within).

 

I am guessing this is a widebeam or some other kind of boat, since a kitchen island in a narrowboat would mean massive compromises for a walkway each side; and if walkway was only one side....its not an island.