Turning Gas On And Off At The Bottle

[sailingjupiter]

I'm just in the process of trying to get my boats gas installation upto the BSS standard.

I now have a dedicated gas bottle holder with a lid and drain. The only place in the locker to put the container means that the lid is difficult to get on and off.

So my question is - when leaving the boat is it necessary to turn the gas off at the bottle or is it OK (and safe) to just turn the gas off at the tap mounted just outside the bottle?

I know that "belt and braces" says to turn it off at the bottle but is it usual to leave switched on at the bottle and just isolate at the remote valve? Is this what everyone else does?

Thanks

 

[Piers]

On my previous boat (which had gas) I always used to turn the gas off at the bottle to reduce the pressure in the line in case of leakage.

 

[Norman_E]

My boat has a remote controlled electric gas valve, which I turn off each night, and only need to screw down the manual valve when I leave the boat. Trouble is I don't know where you buy those remote solenoid valves.

 

[lw395]

Personally I turn off at the bottle if leaving the boat for more than a few hours. If you don't have this much confidence in the installation, you have to ask yourself why.
I am fairly religious about turning off at the tap upstream of the cooker, in my not so humble opinion, this tap should be in plain view not in a locker like many boats.
If you can leave the bottle on and your gas doesn't leak away in a fortnight's cruise, then the system doesn't leak too much!
Perhaps I should buy a gas detector. Or another opening porthole!
The two aims of getting the bit of paper and not blowing yourself up may not be that closely related?
I think its important to check over the pipe work a few times a season, make sure its not corroding etc, make sure its not come loose and will not get broken by other gear in rough weather etc.
Gas systems are pretty safe if treated with a little respect.

 

[boatmike]

Theory:
If gas is able to escape from any union including the tap itself and cannot "drain" to sea rather than bilge it ought to be turned off at the bottle.
Practice:
As my gas tap is on the bulkhead inside the boat and all pipes from bottle to there drain down to a locker with a big 'ole in the bottom, I can't be arsed to keep going all the way out in the cold to turn the booger off. When at sea I have a solenoid valve that needs turning on before using gas. When I leave the boat I turn off the tap at the bulkhead.

 

[dansar]

Have been on quite a few boats with the remote controlled electric gas valves fitted and on most of them the valve was already u/s or it packed up. So when we bought our first boat, the gas pipes etc were all replaced but we left out the valve, which means a visit to the gas bottle every time gas is required. At least we know its off or on!!!


dansar

 

[chas]

I always turn the gas off at the bottle when it is not being used. It is just not worth the risk not to. I have about a foot of orange ribbon in the gas locker which, when the bottle is turned on, is left showing outside the locker so it is obvious that the bottle is turned on.

 

[FAITIRA]

[ QUOTE ]
I'm just in the process of trying to get my boats gas installation upto the BSS standard.

I now have a dedicated gas bottle holder with a lid and drain. The only place in the locker to put the container means that the lid is difficult to get on and off.

So my question is - when leaving the boat is it necessary to turn the gas off at the bottle or is it OK (and safe) to just turn the gas off at the tap mounted just outside the bottle?

I know that "belt and braces" says to turn it off at the bottle but is it usual to leave switched on at the bottle and just isolate at the remote valve? Is this what everyone else does?

Thanks

[/ QUOTE ]

I turn off at the bottle when leaving the boat for any length of time, also have a good detector, (google www.nereusalarms.com) which I feel is indispensible if you have gas etc aboard. Bill.

 

[oldsaltoz]

G'day David,

We keep 2 large bottles in a dedicated drained locker up front, fitted with an on-off solenoid that gets turned on and off 4 or 5 times a day (live aboard). also a manual bottle change over valve.

Both must be several years old and never had a problem with them, though we did have a bottle empty itself via a leak near a weld on the base last year.

Sniffer is on 24/7 and tested once a month, also no problems to date.

I think if we found ourselves in a situation that resulted with no one on board for weeks at a time long term I would consider removing the shut off solenoid as they like to be operated frequently to stay free and work properly.

Avagoodweekend......

 

[rogerdog]

Off at the bottle - that way any leakage has to be contained within the vented locker so it (should) drain overboard safely. In addition, to be super safe venting the gas line when leaving the boat is another additional routine you could use when laying her up. A small amount of gas in a confined space will go with a big bang !

 

[Nickcf]

The experts also say not only turn off at the bottle, but turn off the bottle whilst the gas is still ignited at the burner. Obviously important to watch the flame die out and then turn off the burner tap as well!!
This ensures that the pipe is not left pressurised which may gradually leak gas into the bilge.
I would never take any chances with gas.

 

[VicS]

[ QUOTE ]
This ensures that the pipe is not left pressurised which may gradually leak gas into the bilge

[/ QUOTE ] But is only a very smal quanity of gas. Somone will say it'll build up overtime, possibly but i doubt it. However if the gas leaks into the bilges when the bottle is turned off it is leaking into the bilges all the while the bottle is turned on. Thats serious!

 

[boatmike]

Agreed. Thats why I said any leakage possible into the bilge is a no-no. However, proper gas isolator valves are much more efficient than the screw down taps on bottles. These things can leak slowly over time and seep gas into the line and into your boat. IF your gas bottles are installed in a properly draining locker, the pipework in that locker is no risk BUT you need a fully approved isolator valve either in that locker or immediately outside it to shut the system off within the boat.Even if you shut the bottle tap off you should have one of these to ensure the supply is totally isolated. The taps on the top of bottles are there basically to shut the supply off when changing bottles. They SHOULD be able to be relied upon to isolate the bottle but how many times have you seen one corroded to the point that the plastic knob turns independent of the valve or the valve wont turn at all? I have no problem with people turning them off when they leave the boat. Good practice in fact. Don't rely on the boogers though. fit a seperate fully approved gas isolator valve as well. Then if it isolates all pipework inside the boat the worst that can happen is the gas bottle leaks to atmosphere.

 

[snowleopard]

My solenoid valve died after 7 years as a result of moisture getting into the coil - there is some ferrous metal in there which has rusted and expanded. I got a replacement from a local gas shop that specialises in Calor appliances.

The switch to operate the valve is in the galley and I have fitted an LED to warn when it's on. We turn off after every use of the stove. The bottles are in a locker accessed from the foredeck so not a place you want to go when it's cold, wet and dark.

It's important that whatever valve you use for shutting off should be in the self-draining area so that when the valve is shut you know no gas can leak into the bilge.

It's also a good plan to have a Gaslow valve that will close if you get a major leak, e.g. a fractured pipe.

 

[VicS]

[ QUOTE ]
BUT you need a fully approved isolator valve either in that locker or immediately outside

[/ QUOTE ]
You make some very valid points. However the bottle valve is the valve that isolates the supply from the whole installation and it is normally the only valve on the hp side of the regulator. For those reasons it should be shut when the gas is not in use.

If I fitted an approved isolator I would want to put it in the gas locker, not immediately outside it. I believe that is normally considered where a solenoid valve should go. In any case if you are going to fit an isolator because you cannot trust the cylinder valve then surely you want it on the hp side of the regulator, then it must go in the gas locker and the down side is of course in fitting it you have introduced two more joints with potential for leaks.

There is no mention, as far as I can recall, of any additional isolator being required in the Boat Safety Scheme (BSS), which is the yardstick we all use even if it does not specifically apply. Perhaps you should draw the attention of the people responsible for the BSS to the shortcomings of the cylinder valves as the primary isolation valve and suggest that the scheme is revised to include the additional valve you propose.

Solenoid valves and any other LP isolating valves should be seen as a convenience only and not used as a substitute for shutting off the supply at the bottle and/or at an adjacent HP isolator.

You specify a "fully approved isolator valve" but by whom is this valve approved. Presumably there are a string of specifications with which it must comply etc etc. What should we ask for when buying this valve?

 

[mormargh]

Off at the bottle on our boat. Components in between are going to deteriorate over time or be eaten by the gas, with the possible exception of copper piping. Even that collects the debris from flexible gas hose as it degrades.

 

[snowleopard]

Don't count on copper piping not deteriorating over time. I've had leaks in copper fuel and hydraulic lines and one pipe that ran through a space where the holding tank vent exited corroded and flaked off its outer layers.

 

[boatmike]

If you go to ASAP Supplies website and look for part number 307057 you will see an approved gas shut off valve. Its basically approved by the gas manufacturers/suppliers I believe but you have to ask your Corgi guys for the details of the approval authorities.
It is a spring actuated positive shut off mechanism that detects low pressure or over pressure and shuts the system down or can be shut by hand by a 1/4 turn that releases the spring. It's fail safe (spring pressure opens it so if it were to fail it would fail shut not the other way around) It is recommended to be fitted after the regulator, as near to the bottles as possible. If the regulator malfunctions therefore the system shuts down but it's also a manual isolator..
As I said before if all pipework between the regulator and this valve are vented to a drain then from a safety point of view if anything that side of it leaks it goes overboard. In my case I have the valve fitted on the inside of the bulkhead which means that yes, in theory the union to the upstream side of it is a risk but a very small one. My judgement was that fitting it in the warm and dry interior rather than in the locker means it is not subject to corrosion which I judged as more important than the alternative of fitting it in the locker itself. It is also within easy reach and gets used all the time. The code I believe does not require one at all. Neither (I think) does it require a bubble tester which I also have, so fitting it there is not non compliant, it's an extra. Most installed systems don't have one as boatbuilders never fit anything that costs money that they don't have to fit (they are about £40 each) but I have always thought them essential and fitted one.
Perhaps I should say more strongly that I don't disagree with turning the bottles off at the source. If you don't have a really good efficient shut off valve (not just a gas tap) you always should. How many people shut it off every time they leave the boat to go to the pub, or when underway, or when they go to bed at night though? Mine is right there at hand and the gas is only on when I want to use it and otherwise always off. All I am saying is that if you have such a valve fitted you don't rely on the micky mouse needle valves on the regulators which with camping gaz are very prone to jamming, corrosion and breaking. I just don't trust em! ( note to self.... my regulator and tap are due for replacement anyway as they are indeed corroded)

 

[Dipper]

[ QUOTE ]
How many people shut it off every time they leave the boat to go to the pub, or when underway, or when they go to bed at night though?

[/ QUOTE ]

I do the same as chas (except for the orange ribbon). I turn the gas on at the bottle, cook the food/boil the kettle, then turn the gas off at the bottle. I also have a remote solenoid which I use to turn the gas off if I am going to light the hob again within a few minutes.

One advantage of a smallish boat is that when someone is cooking, the other crew member is usually in the cockpit and can operate the gas bottle valve for you! /forums/images/graemlins/grin.gif

 

[Nickcf]

[ QUOTE ]
[ QUOTE ]
This ensures that the pipe is not left pressurised which may gradually leak gas into the bilge

[/ QUOTE ] But is only a very smal quanity of gas. Somone will say it'll build up overtime, possibly but i doubt it. However if the gas leaks into the bilges when the bottle is turned off it is leaking into the bilges all the while the bottle is turned on. Thats serious!

[/ QUOTE ]

As I said it's what the experts would advise- you don't have to do it but it's sensible. In fact there may not be a serious leak but all pressured systems deflate over time (eg car tyres), so, for example if you use the gas once a week for ten minutes and leave the pipe pressurised (with the bottle turned off) it has a week to leak out every time. It's the risk of a build up you have to avoid.