vyv_cox
Well-known member
I think cunifer is used as a substitute for steel Bundy pipes because it is corrosion resistant but has considerably greater strength than copper.
Gas
- Thread starter pmagowan
- Start date
I think cunifer is used as a substitute for steel Bundy pipes because it is corrosion resistant but has considerably greater strength than copper.
prv
Well-known member
It's interesting to note that the UK standard (mostly driven by the BSS) is copper pipe wherever possible and minimise the amount of flexible hose - but in the US they instead prefer to minimise the number of joints. This means that, if you have a gimballed stove, you have a continuous length of flexible hose running from the stove right up to and into the gas locker, and only join it to a manifold (or direct to the regulator) there. I have to say I find the US approach intuitively more convincing - thick-walled, fibre-reinforced hose feels more robust than thin copper tube, and each of the compression joints in a standard UK system is another potential leak.
Because of their no-joints philosophy, the US also lack the isolating tap next to the cooker that we all have. Instead, they have a 12v solenoid-operated valve back in the gas locker, with a control switch in the galley. Again, this seems like an improvement on our approach, where we isolate the last couple of feet of the system (the part which is visible, and where we would probably notice a leak anyway) and leave pressurised the concealed and un-checked run through the boat. Even if I was installing UK-style copper pipe, I think I would adopt the solenoid switch in a new system. In the unlikely event of complete electrical failure I imagine you can probably operate the valve manually with a screwdriver, or if not, install a manual bypass valve in parallel.
Pete
Because of their no-joints philosophy, the US also lack the isolating tap next to the cooker that we all have. Instead, they have a 12v solenoid-operated valve back in the gas locker, with a control switch in the galley. Again, this seems like an improvement on our approach, where we isolate the last couple of feet of the system (the part which is visible, and where we would probably notice a leak anyway) and leave pressurised the concealed and un-checked run through the boat. Even if I was installing UK-style copper pipe, I think I would adopt the solenoid switch in a new system. In the unlikely event of complete electrical failure I imagine you can probably operate the valve manually with a screwdriver, or if not, install a manual bypass valve in parallel.
Pete
Avocet
Well-known member
No, it has a lid (though the lid is by no means gas-tight). The tops of the sides, however, do come up a bit higher than the top of the regulator
pmagowan
Well-known member
Interesting. That is the current setup in my system. Flexible tube direct from the stove to the gas regulator on the bottle. My system is not good as I have no gas locker but I turn the gas off at the bottle. I don't have the 12v solenoid as it is easy to reach in and turn off the bottle. I like the sound of a failsafe solenoid to keep the gas off when not in use. I wonder could it even be wired to the gas alarm so that if a leak is detected it turns off the gas. The only worry would be having something electrical in the gas locker and the potential for a spark although I am sure this can be safely accomplished.
prv
Well-known member
Fair enough. The solenoid allows you to carry on doing the same in a bigger boat with the locker further away.
Yes, there are products available that do exactly this. I'm not sure if the alarm and valve come as a set, or if you simply buy the right gas alarm which has an output for the valve.
Since the solenoid valve is specifically designed to be installed in the gas locker, it's certified as "intrinsically safe", ie will not ignite an explosive atmosphere.
Pete
RobWheatley
New member
The main problem with flexible hose is that it is easier to damage by heat and abrasion than solid metal, yes there are less joints but generally more chance of failure (and it would all have to be replace every 5 years). We have the isolation valve (required under GSIUR 1998) so that if the flex fails it can be isolated at that point for safety (it also HAS to have a proper fitting to convert from copper to flex (barbed)) plus if you have another appliance there will be joins in it.
The use of a solenoid IS a very good idea if connected to the gas alarm and also with emergency stop buttons however it is not a requirement under our regs.
pmagowan
Well-known member
I do like this solenoid idea. That is the way forward. It would be possible to link it in to fire alarms, gas alarms, CO alarms etc. It could even be wired to the main cabin lights such that when you go to bed you always know the gas is off! This may be getting a little complicated! 
prv
Well-known member
In the US model they don't, they run each appliance's hose back to a manifold in the gas locker. The only permitted joints outside the gas locker are between a hose and the appliance it feeds.
I think both systems have their good points, and both their potential failures.
I've not heard of a solenoid being used with an "emergency stop" button, it's usually a "gas on" / "gas off" switch. Typically mounted above the counter-top next to the cooker, so you turn it on before use and turn it off after.
It's interesting that you mention the Installation and Use regs, because I was under the impression they didn't apply to seagoing boats. However, it's a very long time since I last read them.
Pete
prv
Well-known member
It could even be wired to the main cabin lights such that when you go to bed you always know the gas is off! This may be getting a little complicated!
Heh. I wouldn't go quite that far, but it's certainly true that when you're wiring things up from scratch you think of all sorts of useful behaviour that's never included in a production boat.
In my case it would be handy for the gas to turn off when I turn off the master electrics switch - I have been known to forget and leave it on when I leave the boat. I do plan to fit a solenoid and switch one day, but it's a long way down the list.
Pete
pmagowan
Well-known member
We could put motorised valves on all the sea cocks and then you simply flick a switch as you leave and the whole boat shuts down!
NickTrevethan
New member
The whole gas tight locker interests me. We have a none gas tight draining gas locker. It opens on the side but the top of bottles sit 12 inches below the bottom of the door.
Small seepages would drain, but no gas locker I have encountered would contain a major leak due to a failed regulator etc.
Small seepages would drain, but no gas locker I have encountered would contain a major leak due to a failed regulator etc.
pmagowan
Well-known member
I think trying to make a gas locker completely gas tight would be folly. The locker would simply pressurise in the event of a leak and then blow the lid when you went to open it. I don't think it would be a good idea. You could put a pressure release valve but a simple hole is more effective i would have thought.
Rigger Mortice
N/A
I think the idea is that it is gas tight except for the drain.
That's how I made mine which has a side opening door. The door and everything else is air tight but the drain is open to the air.
That's how I made mine which has a side opening door. The door and everything else is air tight but the drain is open to the air.
pmagowan
Well-known member
That makes more sense but only really if the lid opens to somewhere where the gas could drain into the boat. If not then I can't see the point. It would need to be a pretty catastrophic leak for a normal locker to be overwhelmed with a reasonable lid, I would have thought.
JumbleDuck
Well-known member
We could put motorised valves on all the sea cocks and then you simply flick a switch as you leave and the whole boat shuts down!
I'd love some sort of remote control - preferably mechanical - for my engine cooling water inlet, as it is a real stretch for me. Since I am 6'4" I have no idea how titchy people would manage it.
prv
Well-known member
We could put motorised valves on all the sea cocks and then you simply flick a switch as you leave and the whole boat shuts down!
I don't close the seacocks when I leave the boat. I am confident that the hoses and clamps will remain secure against a few inches' head of water. I do exercise them when I'm in the relevant lockers, to prevent the balls crusting up, but the heads outlet in particular is right at the bottom of the cockpit locker so that doesn't get moved very often (also why it doesn't get closed).
Pete
prv
Well-known member
If we ever put a holding tank back into Ariam (which will probably mean never again carrying a dinghy, due to lack of space) then there will need to be an easy way to operate the seacock mentioned in my post above. I think I would make up a quadrant to go onto the spindle in place of the handle, with a sturdy push/pull morse cable driving it.
Pete
Rigger Mortice
N/A
That's exactly what happens in my boat. The gas locker is inside the cockpit locker under the coamings. Any leak would drain into the cockpit locker from where some of it would inevitably drain into the cabin. In the event of a catastrophic failure of the regulator I would hope that the gas would be forced out through the drain. It would be interesting, if it ever happened, to put a light to it to see how far the flame would go!!!
RobWheatley
New member
RUN.....................................................
NickTrevethan
New member
Motorised ball valves exist. I looked at one for about 600 700 pounds to close my exhaust on a sailboat which when heeled could scoop water in. Poorly designed exhaust run that I couldn't reroute.