Propane Question - Should I be Worried?

[Mirage35]

One last issue that I wasn't able to resolve before putting the boat to bed for the winter. Didn't have time to ask the locals before we all go into hibernation.

Propane system may have a leak, but I'm not sure.

It's a typical installation for the Great Lakes and probably elsewhere, standard North American components. What I notice is that in the propane locker I hear a slight hissing sound (with the tank valve open and the solenoid closed) and *maybe* notice a bit of gas smell. The smell might be my imagination, but is the noise a normal part of regulator or other operation?

I know that we were losing gas before I got the tanks re-valved, and am maybe a bit paranoid after that (still a healthy attitude around propane ) but hoped that the problem would then go away. Has it? I'm not sure. I welcome your comments.

(For the propane sceptics: the boat has a well designed gas locker with overboard drain. There is a solenoid valve in the locker controlled by the LPG breaker and sniffers in the galley and forward cabin. We manually close the tank when we don't anticipate an immediate need. We're prepared to live with the residual risk.)

[Dockhead]

The regulator should be silent. Paranoia is an absolutely rational attitudes towards propane on a boat.

If you do have a leak, you should be able to find it with soapy water and an artist's paint brush.

Before opening the valve again, I would suggest doing two things with your gas locker:

(a) make sure that the drain doesn't have any kinks in it where water could stand and form a lock which water can get through, but gas can't. Frighteningly common problem with gas lockers -- don't ask me how I know

(b) Go through your gas locker with extreme care and make sure there are no bad grommets or screw holes or cracks or any kind of communication with the inside of the boat. I know of one case of an extremely well taken care of boat which exploded due to a leak between the gas locker and the hull interior, with the result that one young man lost a leg. The boat was blown to smithereens; it's a miracle no one was killed.

Rather than looking for a leak, you might consider a more radical approach, as an alternative: Just take it all out and reinstall it with new hose, grommets, seals, regulator, and fittings. It's not that expensive, and that stuff should be renewed from time to time anyway.

Good luck and let us know how you get on.

[Mirage35]

Thanks, you've confirmed what I didn't really want to hear. But be assured that the condition and function of the propane locker and drain was the first thing I checked when I started worrying about this.

[Dockhead]

Originally Posted by AnglaisInHull

Thanks, you've confirmed what I didn't really want to hear. But be assured that the condition and function of the propane locker and drain was the first thing I checked when I started worrying about this.

Good for you

If it were me, I'd probably go straight to the radical option. The regulators, hoses, and fittings aren't expensive, and you get a fresh start. Can be done in an hour or two once you've sourced all the parts. Approximately 2-beer job.

Can't be too careful with that stuff, but you seem to know that. My next boat will have all electric cooking.

[Jd1]

If you hear hissing you either have exceptional hearing or you have a VERY substantial leak!
A tiny leak will not give you any sound warnings.
Quickest way to test things would be to do a leak-down test. Leave the solenoid closed, open the tank valve and look at the pressure on the gauge that you hopefully have in that section of circuit. Now close the tank valve. The pressure should stay at the same reading if all is well. If it drops rapidly you have a BIG problem, if it takes maybe half hour or more to leak down you have a problem but IMHO it isn't an emergency (don't quote me on that because in reality any leak is too much of a leak).
If that test shows no leaks than you go to step two .... open the solenoid, shut off all gas consumers on the boat, open the tank valve, register the pressure gauge reading, close the tank valve and see what the gas gauge does. It should again stay at the same reading.

[Mirage35]

Also a good confirmation, and one that seems clear and obvious now that I have my head out of the sand .

Propane system testing and possible refit are now on the list for the spring.

[boatpoker]

I have to assume that you don't have a pressure gauge, if that is correct, install one.

Also having a hand held propane leak detector on board is useful.

[Dockhead]

Originally Posted by boatpoker

I have to assume that you don't have a pressure gauge, if that is correct, install one.

Also having a hand held propane leak detector on board is useful.

I don't have a pressure gauge on my installation -- it's not typical in the UK. What is good for? Leakdown tests? We use bubblers for that.

I will be doing over my gas system during this winter, and that would be a good time for me to add a pressure gauge, if there is some need for it.

[Mirage35]

Originally Posted by boatpoker

I have to assume that you don't have a pressure gauge, if that is correct, install one.

Also having a hand held propane leak detector on board is useful.

Actually I have a pressure gauge - you should instead assume that I wasn't paying appropriate attention to it. Like I said, head in the sand.

[rwidman]

Good advice has been given. I suggest that you work on this sooner, rather than later. In the meantime, turn off the propane at the tank(s).

I would think that if you can hear the leak, you will be out of propane within a few days. That would be a pretty big leak.

[boatpoker]

Originally Posted by Dockhead

I don't have a pressure gauge on my installation -- it's not typical in the UK. What is good for? Leakdown tests? We use bubblers for that.

I will be doing over my gas system during this winter, and that would be a good time for me to add a pressure gauge, if there is some need for it.

What is a "bubbler" ? We probably have different terminology.
Pressure gauge, leak indication at a glance and a really cheap method.

A pressure gauge should be installed installed on the cylinder side of the pressure regulator. This gauge allows you to quickly and easily check the system for leaks via a “leak-down test.” To conduct a leak-down test, turn on the stove or grill, then close all the burner valves, leaving the solenoid switch on. Note the pressure gauge reading, then close the tank valve – the gauge reading should remain constant for at least three minutes. If the pressure drops, then you have a leak (or leaks) and must inspect the entire system before using it again.

[Dockhead]

Originally Posted by boatpoker

Pressure gauge, Leak indication at a glance and a really cheap method.

A pressure gauge should be installed installed on the cylinder side of the pressure regulator. This gauge allows you to quickly and easily check the system for leaks via a “leak-down test.” To conduct a leak-down test, turn on the stove or grill, then close all the burner valves, leaving the solenoid switch on. Note the pressure gauge reading, then close the tank valve – the gauge reading should remain constant for at least three minutes. If the pressure drops, then you have a leak (or leaks) and must inspect the entire system before using it again.

OK, that's what we use a bubbler for. I think I would prefer the bubbler -- which is what I have been planning to install -- as it will show an extremely tiny leak, and will show it instantly, without waiting for the whole tank pressure to change measurably.

http://www.alde.co.uk/itemdetails.php?itemId=53

A lot more expensive than a gauge, but looks to me like worth it.

[a64pilot]

Want is a bubbler? The gauge work as you can leave the valve off for extended times and if there is any leak at all it will show up over time

[Dockhead]

Originally Posted by a64pilot

Want is a bubbler? The gauge work as you can leave the valve off for extended times and if there is any leak at all it will show up over time

See above. A bubbler shows in real time whether even very tiny volumes of gas are passing through the system. You don't have to wait to see if pressure falls measurably.

[TreblePlink]

OK, so without a pressure gauge (which can be used for leak testing) how do you know when you're close to being out of propane?