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Discussion Starter #1
A friend of mine has a new used boat that has a propane cook stove.
I recommended that he put extra effort into checking the propane setup.
This is the email he sent me:
"The propane works perfectly. I left the main valve open for 6 months and (with a good deal of cooking) there’s still propane in the tank."

This is a very smart guy who is planning on sailing with his family. The above comment may have been a joke, a bad one, but assuming it is not, would you guys make some recommendations as to how to setup the propane and what to do and not do. I'm pretty sure I can get him to get an account here.
 

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Telstar 28
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Generally, the tank's valve should be shut off unless you are using the propane.
 

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Telstar 28
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Even with a solenoid, I'd prefer to manually shut off the tank when not in use.
 

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He should probably install an electric solenoid shutoff valve. Then the only effort required would be to flip a switch :)
Agree. I have one in the gas locker switched from the main panel and another near the stove with a switch in the galley (I have a jaundiced opinion of the reliability/durability of electrical stuff at sea).

We switch the outdoors one on when we come aboard and then manage the gas from the other one. We generally switch the solenoid off to douse the last flame on the stove, burning off the last of the gas in the line.
 

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Splashed
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Even with a solenoid, I'd prefer to manually shut off the tank when not in use.
Totally agree, and I think Omatako's way is great. They should probably also install a gas detector.. With that laid back approach, it seems like he might need all the extra safety stuff he can get? :D
 

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Freedom 39
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Tell him to continue with the practice of leaving the propane on if he is satisfied with it. However, he should install blowers that turn over the air every few minutes 24/7, including the bilge, and have a large automatic fire suppression system installed in case the blower fails. The fire suppression system won't prevent the impending explosion but may be able to douse any still smoldering bits that are still floating. If he is a real safety "nut" a gas monitor might be good too.:D

Propane should be off when not in use, period.

I think I read the sentence correctly were your friend was described as "smart". Perhaps you meant to say "educated", there is a vast difference between the two terms.:)
 

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Hi,

My 'new' boat has propane. There are two bottles in a sealed container (inside a lazarette) that is vented outside. The lines run through an electronic solenoid and into the cabin, where it is connected to the stove and oven.

During the off season I close the valves on the bottles. When the boat is in the water, I open one of the valves, but I leave the solenoid off unless I am cooking.

It would be safer to open and close the tank valve each time, but it is not easy to reach, and it is not easy to close the seal on the container.

I do test the solenoid periodically, and it does work (no gas flows when the switch is off).

BTW, I had to update both tanks to the Overflow Protection Device (OPD) valves when I had the tanks filled.

Barry
 

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Just turn it off at the tank each time. You don't always remember, but most of the time you will.
I used to have an electrical solenoid, but seawater got into it, so manual it is.
 

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"The propane works perfectly. I left the main valve open for 6 months and (with a good deal of cooking) there’s still propane in the tank."[/COLOR][/FONT][/SIZE]
Your friend is lucky. Clearly there are no leaks in his system.

But the obvious reply to this attitude is that a leak can DEVELOP.

None of us operates our propane system with a known leak. But we turn the gas off after each use (via the solenoid) because a leak could develop before we have a chance to detect it.

Turning the propane off at the source is a precaution against, not a remedy for, leaks.
 

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David's trying to protect my identity and doing a fine job of it. That was me he sent the email too. I did not mention to him that we have a solenoid on the line. Due to his tutelage, he now has me turning off the valve at the tank when away from the boat for longer than a day. That and other good practices too.

Note that my setup is just like Barry's except I'm not sure about the Overflow Protection Device (OPD). I don't think I have that. To re-use Barry's typing, this is what I have:

There are two bottles in a sealed container (inside a lazarette) that is vented outside. [Only one is connected to the hose at a time. The other stays unconnected and shut.] The lines run through an electronic solenoid and into the cabin, where it is connected to the stove and oven.

During the off season I close the valves on the bottles. When the boat is in the water, I open one of the valves, but I leave the solenoid off unless I am cooking.

Ulinke Barry's mine are easy to reach, So I could turn them off at the tank's valve.

I do test the solenoid periodically [unwittingly when we try to start the stove without flicking the switch], and it does work (no gas flows when the switch is off).

We don't turn off the switch first, to clear the lines. Is that what ought to be done?

Here's the picture from the owner's manual:



Regards
 

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It doesn't really matter whether you turn the switch off before shutting down the stove/oven. I do this as an extra precaution, but the volume of gas in the lines is minimal -- and frankly I'm not sure that it pulls through the line after the solenoid closes without pressure behind it. My stove seems to shut down almost instantaneously when the solenoid closes.

Also, I do not close the tank valve except during the winterized season and when pressure testing the system. I am confident in the operation of the solenoid (which is one advantage to shutting it off before turning off the stove -- you get to test it).

What you do need to do is pressure test the system several times a year (monthly is best). We have some other good threads here on SailNet that discuss pressure testing, if you need help with that.

OPD (overfill protection) valves are something internal to the tank -- it was a precaution added to propane tanks about a decade ago (to prevent overfill -- room for expansion is required). In most cases (horizontal tanks being an exception), you can't fill them anymore unless they've been retrofitted with the OPD valve. More than likely yours have.
 

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Be aware that this isn't a valid test of whether the solenoid is sealing properly. There could still be some gas flowing past the solenoid, but in insufficient quantity to allow the stove to start. However, over a long period of time, it could be enough to cause the boat to blow up. :) A stove needs a minimum amount of gas flowing to it to ignite the burners. Any flow below that amount will be a false negative. This is why you really should turn the propane tank valves off when they're not in use.

I do test the solenoid periodically [unwittingly when we try to start the stove without flicking the switch], and it does work (no gas flows when the switch is off).
 

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Be aware that this isn't a valid test of whether the solenoid is sealing properly. There could still be some gas flowing past the solenoid, but in insufficient quantity to allow the stove to start. However, over a long period of time, it could be enough to cause the boat to blow up. :) A stove needs a minimum amount of gas flowing to it to ignite the burners. Any flow below that amount will be a false negative. This is why you really should turn the propane tank valves off when they're not in use.


SD,

One of the safety features of propane solenoid design is that they are supposed to fail only in the closed position. I'm not saying that the scenario you describe above could not happen, only that it seems unlikely.

I've replaced several solenoid valves over the years, and all of them failed in the same manner -- closed. In each instance this was confirmed by pressure testing the system between the tank and solenoid.

The early symptom prior to complete failure was that they failed to fully open when activated, resulting in anemic/irregular gas flow at the appliance. But even during this stage, they always closed fully when shut off.

I will not argue against manually closing the tank at the source -- if it's convenient, by all means. But I think it's even more important to have a properly functioning solenoid with an always convenient switch, and to make using it part of the routine.

Pressure testing the system is a key part of the routine too.
 

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Discussion Starter #15 (Edited)
I found this recommendation.
It is a good idea to have permanently installed pressure gage.
Propane Systems by Don Casey


Testing
If you are using the stove regularly, you should make a habit of testing the system for leaks. Once a week is not too often.
To test the system, operate the stove, then close all the burner valves, but leave the solenoid switch on. Read the pressure gauge, then turn off the manual valve on the tank. After 3 minutes, read the pressure again. If it is unchanged, wait 15 minutes and read it again. Any drop in pressure indicates a leak that must be located (with soapy water) and stopped. If the system is leak-free, reopen the tank valve, light a burner, then shut off the solenoid as normal. For more information about outfitting a galley, consult Dragged Aboard by Don Casey.

I think that the thing that really gets to me is that you could go a lifetime and never have a problem with a propane system. But if you have one leak in one hose the results can be so catastrophic.
 

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Yes, but even the best of valves can leak. :)
SD,

One of the safety features of propane solenoid design is that they are supposed to fail only in the closed position. I'm not saying that the scenario you describe above could not happen, only that it seems unlikely.

I've replaced several solenoid valves over the years, and all of them failed in the same manner -- closed. In each instance this was confirmed by pressure testing the system between the tank and solenoid.

The early symptom prior to complete failure was that they failed to fully open when activated, resulting in anemic/irregular gas flow at the appliance. But even during this stage, they always closed fully when shut off.

I will not argue against manually closing the tank at the source -- if it's convenient, by all means. But I think it's even more important to have a properly functioning solenoid with an always convenient switch, and to make using it part of the routine.

Pressure testing the system is a key part of the routine too.
 

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Thanks David. I have a pressure guage in the line, right near the tanks. I'll do this method.
 

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Discussion Starter #18
Does anyone have any ideas as to how to test the locker itself for being leak-proof. In this bene51 if the locker were to leak I believe it would leak into the cabin.
I'm only being a real calamity Jane about this because I am in the middle of reading "Total Loss" a collection of 45 first-hand accounts of yacht losses at sea. Fun reading.:mad:
 

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I think it drains overboard through a hose going from the bottom of the locker to an outlet at the lower part of the stern.
 

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I have to admit that I do like the way propane stoves/ovens work on sailboats much better then the Origo alcohol stove that is on my little 27' boat but I am not rushing to switch over to propane for a number of reasons that are mostly cost based but some that are safety based.
Here are some:
- if my alcohol stove burner gets blown out while left unattended then it would either empty the tiny tank into the cabin and not likely be more of a threat to anything then my nose. Even if the liquid fuel leaked out it would not be that much in volume and could be aired out as alcohol evaporates.
- propane is heavier than air and will concentrate in the bilge until the level rises up to, say, the running engine.
- I don't have much real estate to house an extra locker that is vented at the bottom for a propane tank.
- I have a gasoline engine with a (currently) slightly leaky carburator that I am working on and MUST fix so I'll stick with the devil I know for now.

There have been some fantastic explosions on boats due to propane leaks and I could only find one on sailnet that did not have the convincing pictures that some reports did include (down to the waterline) but here is one account: http://www.sailnet.com/forums/gear-maintenance/35916-boat-explodes-norfolk-virginia.html
Propane is a modern wonder but if I had my family on my boat I think that it would be worth the 20 seconds it takes to turn off the propane tank when it is not going to be used for a while. I am not sure what a while is in actual time but it will be a subjective thing to everyone as demonstrated by the variety of attitudes expressed here.
I have a boating friend who is not an advocate of automatic bilge pumps (and he used to own a 44' sailboat). His position is that by using an automatic bilge pump you are never made aware of how much water your pump(s) are putting back overboard until the batteries wear down and your boat sinks. Of course, if you do not have an automatic bilge pump you must check your boat regularly (which you should do anyway) to check the bilges and try to find the ingress of water - and run the pumps. I see a parallel argument here for NOT trusting an electric solenoid or a potentially explosive gas/gas line on a boat. Our electrical modern world is marvelous but it can also lull us into a sense of complacency.
The safeguards (solenoid) and bottom draining locker are required for propane but it is easy (in most cases) to just get up and turn off the tank. I also happen to be a smoker so I am more likely then most to start an inadvertent explosion should there be a leak. Perhaps this is why I would err on the side of precaution when it comes to propane. Other better reasons to be prudent are yourself, family, sailing friends and nice sailboat. How long does it take to shut off and turn on the tank?
 
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