MontanaChinook Posted July 13, 2014 Share Posted July 13, 2014 I started smelling propane yesterday...checked all the connections and they seemed fine. Then I notice a noise...a hissing sound that lasted about a second, and repeated three or four times in about a ten second period. Hiss, Hiss, Hiss...Then nothing for a while. It's the relief valve on my tank. Horizontal mounted tank. I opened the valve and let a bunch of pressure out, and it hasn't happened since. Is this something to worry about?? I'm at about 40% in the tank. How does the valve work? When screwed closed, it just vents when over pressurized? And when unscrewed, it'll let all the propane out? Or will it only let pressure out until it's at a safe level, then stop venting, even though it's unscrewed a bit? I'm just wondering if it should have stopped venting eventually when I had it unscrewed, or what. If this has happened before, I never knew about it. So it would have only happened when driving. I would have noticed if it happened before when I was parked. It was 100 degrees yesterday, if that matters... Quote Link to comment Share on other sites More sharing options...
whyverne14 Posted July 13, 2014 Share Posted July 13, 2014 No it will never stop venting until all the propane is gone. What is venting is the gas that you want to use. It's a liquid in the bottom of the tank that changes to a gas in the top of the tank. Sounds like the vent is doing it's job. This is why you never want to store propane inside. It's very susceptible to temperature changes. Quote Link to comment Share on other sites More sharing options...
zero Posted July 13, 2014 Share Posted July 13, 2014 I started smelling propane yesterday...checked all the connections and they seemed fine. Then I notice a noise...a hissing sound that lasted about a second, and repeated three or four times in about a ten second period. Hiss, Hiss, Hiss...Then nothing for a while. It's the relief valve on my tank. Horizontal mounted tank. I opened the valve and let a bunch of pressure out, and it hasn't happened since. Is this something to worry about?? I'm at about 40% in the tank. How does the valve work? When screwed closed, it just vents when over pressurized? And when unscrewed, it'll let all the propane out? Or will it only let pressure out until it's at a safe level, then stop venting, even though it's unscrewed a bit? I'm just wondering if it should have stopped venting eventually when I had it unscrewed, or what. If this has happened before, I never knew about it. So it would have only happened when driving. I would have noticed if it happened before when I was parked. It was 100 degrees yesterday, if that matters... A 40% filled tank should not be doing that at 100 degrees F. In fact, a "100%" filled tank shouldn't either. I used quotes because a tank, by volume, gets a safe fill at around 80% of its total capacity. A typical 20 lb. tank when filled @ 80 % holds 20 lbs. It actually could hold 25 lbs. but not safely. So I'm calling a 20 lb. tank with 20 lbs. of propane a 100% fill even though it's really only at 80%. Now adays the exchange bottles have less and less gas in them . Walmart sells them with a 15 lb. fill Sounds like you've got a problem unless you got overfilled somewhere. Lot of BS flying at some gas-fill places. Some will tell you a 20 lbs. tank is safely filled at 16 lbs. because 16 is 80% of 20. Nope . They are called "20 lbs." because they hold 20 lbs. when safely filled at 80%. Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 13, 2014 Share Posted July 13, 2014 Your horizontal tank has a bleeder screw that has to be opened in order to fill the tank if it's not opened it won't fill it's about a 1/2" around if it is not tightly screwed down after a refill it most likely was leaking. It is a bleed off valve and when the tank is filled it is left open until liquid comes out the pump is then shut off and the bleeder closed. Just keep an eye on it it's not an over pressure valve. The pressure mostly remains the same as long as there is some propane in it propane boils at around -45* so anything above that is pretty well pressurized yes it will climb when it hot out but not dramatically. So if there is propane in the tank as soon as the valve is closed it will return to the prior pressure you really can’t bleed it off until there is no liquid propane left. Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted July 14, 2014 Author Share Posted July 14, 2014 So because I can be a little thick on this, maybe make it more clear...I didn't really see an answer in there, or maybe it's how I phrased the question. My tank was not doing this before. Within the last couple days, there is propane coming out of the bleeder valve. I smelled it multiple times while I was driving today, and have smelled it since I parked today, and I've only been parked for about a half hour. I turned the screw till propane was venting out, then screwed it back in until it was tight, and no more was coming out. But it still vents now and then. Like I mentioned in the first post, I know it's coming out of the bleeder valve, and I screwed it out and back in yesterday to make sure it was closed. It's not a constant flow. It just comes out in pulses here and there. So you're saying just "keep an eye on it"? Nothing to worry about? Now that I think back, the last time I had it filled, the guy mentioned something about it being strange that no propane came out the bleeder, even though it was full. It was the most full anyone has filled it since I've owned it. Usually it's only about 3/4 full. This time it was completely full and nothing came out the bleeder. Is this a problem? Something to just have checked out when I get into a town, or something to run away from fast because it's about to explode? I only ever pay for the gallons they put in, so whether it's 80% or 100% doesn't matter so much to me. I pay for what I get; no more. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 14, 2014 Share Posted July 14, 2014 This is how a propane cylinder vents:- Quote Link to comment Share on other sites More sharing options...
Bob C Posted July 14, 2014 Share Posted July 14, 2014 Liquid propane should have come out of the bleeder when it got to 80% full. Unless you totally emptied the propane tank before getting it refilled, the tank was full of propane GAS (vapor) with liquid in the bottom of the tank. When they added LIQUID PROPANE, propane GAS (vapor) should have come out of the vent. They do not add gas (vapor) they add liquid but it displaces the vapor which comes out of the bleeder vent. If they filled to tank to 100%, they would have filled it to above the level of the bleeder hole which is not possible without the liquid spraying out of the vent. Quote Link to comment Share on other sites More sharing options...
zero Posted July 14, 2014 Share Posted July 14, 2014 Is this a problem? Something to just have checked out when I get into a town, or something to run away from fast because it's about to explode? I only ever pay for the gallons they put in, so whether it's 80% or 100% doesn't matter so much to me. I pay for what I get; no more. I'd try to find out if there is something wrong with the bleed valve. The percentage of fill can matter a lot - regardless of cost - if someone fills your tank beyond its safe capacity. A bit more touchy with a built-in tank since they can't just stick it on a scale and verify weight. Liquid valve must be used. My Chinook has a sideways tank that is removable. I don't know what you have. If it was mine and I could take it out - I would. Get the Tare Weight specs off the tank as well as the water capacity specs. TW (tare weight) is the weight of the tank when empty. WC (water capacity) is the volume of water that will fit into the tank. Propane weighs 4.2 lbs. per gallon. So knowing the TW and weighing the tank will tell you if it's overfilled or not. Note the liquid-valve should never leak unless it is opened. The relief valve is something totally different. If that leaks - it's either defective or the tank is overfilled. Get the TW and WC specs that are stamped on the OD of the tank. My Chinook tank has a TW of 18 lbs. So when it has 20 lbs. of propane it will weigh 38 lbs. Note that some "20 lb" tanks hold 20 lbs. and some only 18.5 or 19 @ 80% fill.. You have to check the TW and WC numbers. Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted July 14, 2014 Author Share Posted July 14, 2014 Ok, thanks. It's the bleeder valve, so far as I can tell. It's what I think I've been seeing the guys unscrew whenever they fill up my tank. My tank is horizontal, and yes, it's "removable", like any part on my camper is removable...it won't just come right out, but with a lot of PB Blaster and getting some bolts out, it will come out. Well, the fact that it showed it was completely full on the gauge, and the guy mentioned that it was weird that the bleeder didn't vent any gas, and now there is some gas coming out of there every now and then, I guess it's probably a good idea to get it checked out. Quote Link to comment Share on other sites More sharing options...
zero Posted July 15, 2014 Share Posted July 15, 2014 Ok, thanks. It's the bleeder valve, so far as I can tell. It's what I think I've been seeing the guys unscrew whenever they fill up my tank. My tank is horizontal, and yes, it's "removable", like any part on my camper is removable...it won't just come right out, but with a lot of PB Blaster and getting some bolts out, it will come out. Both my Chinooks have a wing-nut on a clamp that makes the tank pretty easy to remove. Not like my Minicruiser that has the tank hard-bolted in. Maybe your's just hasn't been out in a long time and is rusty. Recently I got the built-in tank on my Minicruiser filled. It seems it had not been filled in many years. The gas guy was cursing because the liquid valve was at first stuck. Then when he got it opened with Vise-Grips - and filled the tank - it leaked after he closed it. I fooled around with it and opened and closed it several times and finally it stopped leaking. Just dirty, worn, corroded, or whatever. So far - after that . . is hasn't leaked - yet. I suppose you've got a similar issue. Overfilling cannot make that liquid valve leak. Only the relief valve. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 15, 2014 Share Posted July 15, 2014 Removable horizontal tanks are supposed to be removed to fill. They are supposed to be filled in the upright position but used horizontally. If yours isn't coming out did they fill it in place? Might be the problem Linda S Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted July 15, 2014 Author Share Posted July 15, 2014 I just wanted to get it out so I could bring it someone to have checked out, instead of asking them to crawl under the camper. It's always been filled in-place, with me standing there holding the hatch open for them while they fill it. Honestly...I'm not sure which is the "bleeder" valve and which is the "vent". Or if I definitely have both. But I'm assuming that the visible, easily unscrewed bolt is what the guys have been messing with whenever they fill my tank, so that must be the bleeder. I guess I haven't got over to it when I've heard it venting fast enough to verify that it is definitely the bleeder which is venting. Just not sure if it's the temp swings doing this, or something wrong with it. It just started the last couple days, and it's been 95-100 degrees all those days, dropping down to the 50s or 60s at night. Anyway, I'm back in the "home town" for a couple weeks, so maybe I'll get it checked out. Time to work on a few things I've been putting off while I was on the road. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 15, 2014 Share Posted July 15, 2014 I'd sort the possible propane problem 1st. Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted July 15, 2014 Author Share Posted July 15, 2014 Not sure of the best way to "sort" it without removing the tank first. It's coming out of one of (if there are more than one) vents. Sorting out seems much easier with the tank removed. Quote Link to comment Share on other sites More sharing options...
zero Posted July 15, 2014 Share Posted July 15, 2014 Honestly...I'm not sure which is the "bleeder" valve and which is the "vent". Here are some photos. I've got three Chinook/Chalet tanks here. All pretty much the same except the Chalet tank has no gauge. You need to read the two specs stamped on your tank collar. TW and WC. TW is the empty weight and my 1978 Chinook it is 22.5 lbs. The WC looks like it's stamped 48. That means it holds 48 lbs. of water. That means the tank when properly filled at 60 degrees F takes 20.1 lbs. of propane and will weighs 42.6 lbs. total when properly filled. Any tank place will have a conversion chart on the wall. All they need is the TW and WC specs. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 15, 2014 Share Posted July 15, 2014 Lots of writing on that label in last pic. Any chance we could see it closer? Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted July 15, 2014 Share Posted July 15, 2014 Lots of writing on that label in last pic. Any chance we could see it closer? Linda S Here it is. States that the tank must be filled and used when horizontal only. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 15, 2014 Share Posted July 15, 2014 Thanks I didn't know there were different types of removable tanks. All I ever heard of was the ones that have to be filled upright. I only have ASME tanks on my RV's Linda S Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 15, 2014 Share Posted July 15, 2014 I believe John (Waiter) had a horizontal (in operation) tank that could be filled in either the horizontal or vertical position. Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 15, 2014 Share Posted July 15, 2014 If you have a regulator near the tank it may well be a single stage regulator they do vent and you could be smelling that the newer two stage won't. I believe the horizontal tanks that have an offset valve does not have a float to keep it from being over filled all though it is hard to do as long as the bleed valve is open and I also think they can not be recertified only the tanks with the valve in the center can. I really do not believe it is venting it takes a lot of pressure to make them vent however the bleeder valve certainly can leak. I used to use MR Bubbles and a spray bottle to check for A/C leaks it blows really big bubbles if some thing is leaking! Quote Link to comment Share on other sites More sharing options...
zero Posted July 15, 2014 Share Posted July 15, 2014 Thanks I didn't know there were different types of removable tanks. All I ever heard of was the ones that have to be filled upright. I only have ASME tanks on my RV's Linda S The horizontal tank in my 77 Chalet (also made by Chinook) is quite different then the two tanks in my 77 and 78 Chinooks. Regulator setup is different too. Chalet has two separate regs - a high and a low. That's something I've rarely seen in RVs. That being said, a two-stage regulator like most all RVs use now is basically similar. Just two regulators crammed together. Quote Link to comment Share on other sites More sharing options...
zero Posted July 15, 2014 Share Posted July 15, 2014 I believe the horizontal tanks that have an offset valve does not have a float to keep it from being over filled all though it is hard to do as long as the bleed valve is open and I also think they can not be recertified only the tanks with the valve in the center can. The older horizontal tanks like Chinooks have with Prestolite fill-valves are exempt from the regs requiring a float and overfill prevention device. When inspected and recertified - they just get a new warning sticker alerting the filler that the tank has no overfill protection device. I've got two old tanks here that were recertified recently. One just a few months ago. Quote Link to comment Share on other sites More sharing options...
kgibson4 Posted July 15, 2014 Share Posted July 15, 2014 (edited) This is the tank in my '87 Odyssey. It apparently needs to be removed and set vertically to be filled. The regulator seems to be a 2-stage and is separate from the tank. I haven't yet had to fill it. Edited August 5, 2014 by kgibson4 Quote Link to comment Share on other sites More sharing options...
linda s Posted July 16, 2014 Share Posted July 16, 2014 This is the tank in my '87 Odyssey. It apparently needs to be removed and set vertically to be filled. The regulator seems to be a 2-stage and is separate from the tank. I haven't yet had to fill it. Your regulator by the way appears to be in the wrong position. There is a vent on one of those metal circles that needs to be facing up. Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted July 16, 2014 Share Posted July 16, 2014 Your regulator by the way appears to be in the wrong position. There is a vent on one of those metal circles that needs to be facing up. Linda S I can't see which regulator is one there but the vent is supposed to point down. Never up. Regs come with vertical vents or horizontal vents. I can't tell which is on that tank. Maybe your eyes are better then mine. Quote Link to comment Share on other sites More sharing options...
whyverne14 Posted July 16, 2014 Share Posted July 16, 2014 I hate to say anything about propane because it can be so dangerous. But I do have some experience. Over 2500 flights as a hot air balloon pilot. I still maintain that your safety vent vented at 100 degrees plus and that's a good thing. It means it works. The valve is on a spring and if internal pressures get too high it vents a bit out, then the spring closes the valve again. It's hard to make all springs exactly the same so some are more sensitive than others. I would have six tanks in a hot trailer and some would vent, some wouldn't. Too many variables to know why. A common misconception is that a full tank is under the most pressure. That's not necessarily true. A full tank is 80% full of LPG, Liquid Petroleum Gas. When it is a liquid, it is -40 degrees. It's pretty hard to warm that up. But a tank that is nearing empty has mostly propane vapor in it, much easier to heat up, causing a pressure build up. I would often hear that an empty tank is the more dangerous; because unless you drain them totally with the vent, there is always some gas in there which will expand with higher temperatures and create high pressures. A friend of mine burned down his house by taking an "empty" tank inside. BTW when you say that propane is -40 degrees, you don't have to say C or F cause they're both the same at that temperature. Quote Link to comment Share on other sites More sharing options...
zero Posted July 16, 2014 Share Posted July 16, 2014 I still maintain that your safety vent vented at 100 degrees plus and that's a good thing. It means it works A properly filled tank at 100F is not supposed to be forcing open the relief valve. Having one leak does not necessarily mean it's working. If the tank was overfilled and it cracked open - then yes, it's working and that's a good thing. If the tank was properly filled - and the relief valve cracked open - then it's not good and the valve is defective. A full tank at the -40 C or F that you mentioned has 0 PSI. A full tank at 32F has approx. 60 PSI. A full tank at 72F has 130 PSI. A full tank at 100F has 200 PSI. Note the relief valve on a standard DOT propane tank has a relief valve set to crack open at 375 PSI. An ASME tank at 250 PSI with some variations. The tank in this guy's Chinook is a DOT tank and has a 375 PSI relief valve. Besides all that - he is not sure if it's the relief valve or the liquid valve that is leaking. Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted July 16, 2014 Author Share Posted July 16, 2014 Whichever it is, "leaking" still doesn't seem like the right description to me. I don't have propane experience, so obviously I'm not the one to make the call on this, but like I mentioned, I can hear when it does this. It is absolutely not a leak like any of the leaks I've found in my system before, where I can smell propane, and find a steady stream of bubbles when I use soapy water. This is an actual audible hiss, three or four or five in a row, then nothing. Either way, I'll see what the local propane place thinks. Whether or not it was overfilled, it's down just below 40% right now. So I don't think that it would be venting from overfilling, still, unless there's something I'm missing (completely possible)... Thanks. Quote Link to comment Share on other sites More sharing options...
zero Posted July 16, 2014 Share Posted July 16, 2014 I have no way of knowing what's going on. But - here's what DOES happen at times. The relief-valve often sits for 10-20-30 years without ever opening. Many if not most have never opened since new. It is only there to open in an emergency high pressure situation. Like any valve that goes unused for many years - when it DOES open - it may not want to close all the way and seal again. It's not something that is supposed be opening EVER if the tank is always properly filled and your RV hasn't gotten super-heated. My point being - if someone accidentally overfilled it recently and that relief valve cracked open for the first time in 30 years - it may now be a chronic leaker. All it is a a piece of metal (or plastic) against a seat with a spring holding it closed. If the spring wears - it opens prematurely. If that seat gets any crud in it - it won't close again and seal properly. Ever turn on a water-valve that hadn't been used in years and then find out when you turned it back off it leaked? That's common and not much different then a relief valve. Same for the temp-pressure relief valves in water-heaters. Let them crack open once after years of being closed - and sometimes they close fine and sometimes never close right again and they have to be replaced. The difference is - hot water heater safety valves are supposed to be exercised manually and open at least once a year. The valve in a propane tank gets no exercise until an emergency takes place. Quote Link to comment Share on other sites More sharing options...
WME Posted July 16, 2014 Share Posted July 16, 2014 Bubble check everything around the fill valve and see what is actually leaking. Quote Link to comment Share on other sites More sharing options...
kgibson4 Posted July 16, 2014 Share Posted July 16, 2014 I can't see which regulator is one there but the vent is supposed to point down. Never up. Regs come with vertical vents or horizontal vents. I can't tell which is on that tank. Maybe your eyes are better then mine. Linda and JD, Thank you so much for alerting me to this situation. I never would have known. Here's a better pic of the regulator. I take it that bell-shaped business on the left side with the screen over it is the vent and it should point down. I will take care of that! Thanks Quote Link to comment Share on other sites More sharing options...
zero Posted July 16, 2014 Share Posted July 16, 2014 Linda and JD, Thank you so much for alerting me to this situation. I never would have known. Here's a better pic of the regulator. I take it that bell-shaped business on the left side with the screen over it is the vent and it should point down. I will take care of that! Thanks Looks like you've got the wrong type of regulator if you've it screwed in straight into the tank. Supposed to have a regulator made for a horizontal mount (with a vertical vent). Main thing is that vent points straight down so it cannot collect any moisture. The regulator in your photo is for a vertical type mount. The terminology is a little confusing. A new regulator sold as "horizontal" has a vertical vent when installed horizontally. Quote Link to comment Share on other sites More sharing options...
kgibson4 Posted July 16, 2014 Share Posted July 16, 2014 Actually, the regulator was just loose, flopping around in the propane compartment and connected to the tank and the main coach supply line by rubber hoses. I intend to mount it vertically to the side of the compartment, provided of course, that I can get the tank out past it when refilling. This was apparently all cobbled together when the tank and regulator were replaced sometime after '02. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 16, 2014 Share Posted July 16, 2014 Whichever it is, "leaking" still doesn't seem like the right description to me. I don't have propane experience, so obviously I'm not the one to make the call on this, but like I mentioned, I can hear when it does this. It is absolutely not a leak like any of the leaks I've found in my system before, where I can smell propane, and find a steady stream of bubbles when I use soapy water. This is an actual audible hiss, three or four or five in a row, then nothing. Either way, I'll see what the local propane place thinks. Whether or not it was overfilled, it's down just below 40% right now. So I don't think that it would be venting from overfilling, still, unless there's something I'm missing (completely possible)... Thanks. Believe I would replace the regulator. Quote Link to comment Share on other sites More sharing options...
zero Posted July 17, 2014 Share Posted July 17, 2014 Actually, the regulator was just loose, flopping around in the propane compartment and connected to the tank and the main coach supply line by rubber hoses. I intend to mount it vertically to the side of the compartment, provided of course, that I can get the tank out past it when refilling. This was apparently all cobbled together when the tank and regulator were replaced sometime after '02. Many companies that sell regulators say to change them every 10 years. But hey . . they want to sell their products. Some new studies show regulators can last at least 25 years and still be safe. I changed mine this year. The original 2-stage was working fine but 25 years old. I opted to buy a new one and the new one last two days and started leaking. To Camco's credit - I called them up and they sent me a new replacement right out. Got a person on the phone who spoke English and was in the USA. They did that with me having no receipt or proof of purchase. I just emailed them a photo of my failed regulator and they sent me a new one right away. For $18 - it's a cheap investment. If you don't want to replace your's - you might consider buying a spare and keeping it with you. Quote Link to comment Share on other sites More sharing options...
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