Gas

vyv_cox

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I think SS work hardens also so any movement in it would make it more and more brittle. The hose pipe protection might be worth a thought. Would it risk trapping moisture next to the copper and promoting corrosion?

Almost all metals work harden, but 'work' in this context means plastic deformation, not a bit of elastic deflection. Unless you are frequently bending the tubing it will not work harden. Copper is rather better at this than stainless steel but it is a scenario that should never occur in a properly designed system.

And yes, our hoses and regulators are replaced at five year intervals.
 

Tranona

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Can you vent it from high up in the locker as long as and route to the bilges is above the vent?

No. Gas is heavier than air so the vent has to be below the level of the bottom of the cylinder as the BSS diagrams show. The easiest way to achieve this is to have a gas tight top access locker - you can buy them ready made, mount in the stern of the boat just below the deck with the drain to a vent on the transom above the waterline. On my Bavaria the cockpit is completely open and drains through the open transom, so my locker is a GRP moulding under the sidedeck but with an open access door into the cockpit - easy and neat solution but not possible on a boat with a traditional cockpit and transom.

The problem you will find with your Honeybee is that there may not be enough depth in the stern locker to get the gas bottle under the deck with the bottom of the bottle above the waterline. Same problem on my Eventide, so I have a Taylors paraffin cooker and no gas.
 

VicS

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A couple of diagrams from an old PBO which in conjunction with the BSS Scheme might be useful.

(btw you have found the full archived version of BSS Chapter 7, not jut the revised notes for inspection?)

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No. Gas is heavier than air so the vent has to be below the level of the bottom of the cylinder as the BSS diagrams show. The easiest way to achieve this is to have a gas tight top access locker.

Not strictly true.

If the vent can't be at the bottom of the locker ie due to it being below the waterline, you are allowed to fill the area around the cylinders to a level of your vent (there is probably a limit as to how high you can go)
The material spec eludes me I'm afraid, but call your local BSS examiner, I'm sure they can help

Taken from bss checking procedures
Any area in the cylinder locker below the drain that could retain leaked LPG must be filled with LPG-resistant material.

I'm not convinced that the locker even needs to be gas tight. Gas is heavier than air so sinks to the bottom of the locker
Mine has a lift out wooden panel with no seals, she passed the BSS 2 weeks ago. Side entry would obviously be a different matter

And yes I would fit a bubble tester. It's not there to constantly look at, it is there so you can see if you have any system leaks when you turn on the gas supply
 
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Vara

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Addition to note eight in the diagram Vic posted. Open, ie turn on all gas burners on cooker and the operate bubble tester so that it tests the function of the cooker as well as integrity of piping. From Alde instructions.
 
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(btw you have found the full archived version of BSS Chapter 7, not jut the revised notes for inspection?
Yes, I found it 20 minutes ago. https://www.waterways.org.uk/pdf/bss_guide
Interestingly Chap 7 recommends that pipes are fixed at least every 500mm. The PBO suggestion is to fix every 150mm.
I do wonder if fixing by loosely passing through a short length of hose pipe is the best way of doing it. A length of 8mm copper pipe would still be able to vibrate if it were held in place by a 13mm hose. Maybe a more rigid fixing...ie a proper pipe clip...is better?
 
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Talulah

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... A length of 8mm copper pipe would still be able to vibrate if it were held in place by a 13mm hose..
In practice, when the copper tube is unrolled you never get it perfectly straight so as you pass it down a conduit it is in contact on the inside of the conduit at various places preventing it from rattling around.
 

VicS

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Interestingly Chap 7 recommends that pipes are fixed at least every 500mm. The PBO suggestion is to fix every 150mm.
I'd not noticed that discrepancy before.
One seems unnecessarily close, the other not really close enough

The PBO diags ( IIRC from an article by Peter Spreadborough of Southampton Calor Centre) are pretty old, maybe predating the current BSS. Perhaps the close spacing is appropriate for a sea going vessel whereas the BSS is targeted at boats using rivers and canals etc
 
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I'd not noticed that discrepancy before.
One seems unnecessarily close, the other not really close enough

The PBO diags ( IIRC from an article by Peter Spreadborough of Southampton Calor Centre) are pretty old, maybe predating the current BSS. Perhaps the close spacing is appropriate for a sea going vessel whereas the BSS is targeted at boats using rivers and canals etc

The BSS spec does say that a pipe must be securely fixed at more more than 150mm from any connections; presumably to prevent vibration from affecting compression joints.
Maybe the writer of that article misread the BSS rules or has simply decided that a little over-specifying is a good idea? TBH my gut reaction would be to go for 150mm.
 

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We have a top-access bottle locker in the lazarette and it's JUST high enough up to be able to get a drain from the bottom to go through the transom above the waterline. There's not much fall on the pipe tough. A following wave will shove water back up it, but it comes out again. The gas bottle is on a turntable in the locker so I can rotate it round to screw the regulator into it. The turntable also means the bottom of the bottle isn't sat in water.

We replace the short bit of flexible hose and regulator every 5 years. They're obviously within the locker anyway. Also inside the locker is an Alde bubble tester (and a small bit of mirror stuck on so I can see the bubbles more easily looking from above). From the bubble tester, there's a T piece and then I have two copper pipes with no joints in them coming out of the gas locker. One is for the cooker, the other for a Propex heater. The cooker isn't gimballed so there's no flexi hose. The only two unions in the system that aren't inside the gas locker are on the cooker and heater.
 

lw395

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We have a top-access bottle locker in the lazarette and it's JUST high enough up to be able to get a drain from the bottom to go through the transom above the waterline. There's not much fall on the pipe tough. A following wave will shove water back up it, but it comes out again. The gas bottle is on a turntable in the locker so I can rotate it round to screw the regulator into it. The turntable also means the bottom of the bottle isn't sat in water.

We replace the short bit of flexible hose and regulator every 5 years. They're obviously within the locker anyway. Also inside the locker is an Alde bubble tester (and a small bit of mirror stuck on so I can see the bubbles more easily looking from above). From the bubble tester, there's a T piece and then I have two copper pipes with no joints in them coming out of the gas locker. One is for the cooker, the other for a Propex heater. The cooker isn't gimballed so there's no flexi hose. The only two unions in the system that aren't inside the gas locker are on the cooker and heater.

Are you saying that the top of the locker is open to the lazarette?
 

pmagowan

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I'm not sure it sais that. All joints must be visible for inspection but not pipes.
Hoses however are required to be visible along their entire length.

I took this to mean that they should be visible;

Although you will not be required to expose all
the pipework for the BSS examination, it is important that all parts
of the gas system installation pipework on your boat can be
accessed for routine checking, service and replacement. Such
routine inspection of the parts of the LPG system that are not
readily visible is crucial, as damage or deterioration hidden from
everyday view is by its nature a serious risk.
 

pmagowan

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No. Gas is heavier than air so the vent has to be below the level of the bottom of the cylinder as the BSS diagrams show. The easiest way to achieve this is to have a gas tight top access locker - you can buy them ready made, mount in the stern of the boat just below the deck with the drain to a vent on the transom above the waterline. On my Bavaria the cockpit is completely open and drains through the open transom, so my locker is a GRP moulding under the sidedeck but with an open access door into the cockpit - easy and neat solution but not possible on a boat with a traditional cockpit and transom.

The problem you will find with your Honeybee is that there may not be enough depth in the stern locker to get the gas bottle under the deck with the bottom of the bottle above the waterline. Same problem on my Eventide, so I have a Taylors paraffin cooker and no gas.

I took this to mean that it could be higher up the locker as long as the material below it was lpg safe, i.e. not leaky;
Check the location of the cylinder locker drain-openings.
If the drain opening is above the bottom of the locker check that
any area below the drain opening that could retain leaked LPG is filled
with LPG-resistant material.
 
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I took this to mean that it could be higher up the locker as long as the material below it was lpg safe, i.e. not leaky;

Not quite. I think it means, if the drain is a few inches up, that the space must be filled with something to prevent the bottom of the locker acting as a sump in which gas could build up.
 

pmagowan

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Not quite. I think it means, if the drain is a few inches up, that the space must be filled with something to prevent the bottom of the locker acting as a sump in which gas could build up.

I have not looked in great detail but I didn't see a spec for the maximum allowable height so concievably you could fill up the bottom of the locker to whatever height the drain is. What possible reason is there not to let the gas rise up to an appropriate level in which to fit a drain? I know a small amount of gas will be in the locker but it will be minimal and there are no sources of ignition in a gas locker.
 

JumbleDuck

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I think SS work hardens also so any movement in it would make it more and more brittle. The hose pipe protection might be worth a thought. Would it risk trapping moisture next to the copper and promoting corrosion?

Pure copper pipe has a reputation for work hardening and failing as a result of vibration in cars - hence alloys like kunifer for brake pipes. That said, the liquid propane pipe work in my DS is all pure copper, albeit plastic sheathed.
 

AntarcticPilot

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I have not looked in great detail but I didn't see a spec for the maximum allowable height so concievably you could fill up the bottom of the locker to whatever height the drain is. What possible reason is there not to let the gas rise up to an appropriate level in which to fit a drain? I know a small amount of gas will be in the locker but it will be minimal and there are no sources of ignition in a gas locker.


But diffusion will make it likely that you'll have an explosive mixture at some level in the locker, and a spark (e.g. from bottles banging together in a sea) would be bad news.
 
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