Noticed a strange smell around our bus today while checking on it. Finally realized it was the smell of LP.
I checked on the tanks, which I'm positive I had firmly shut off before the recent cold spell. We have two horizontal tanks. One was about 2/3 full last time I looked. When I opened the cover on the tanks, the tank which was full has a coating of frost on the end of it, with a small pile of what looks like fine snow built up under the fill valve. Pressure gauge on both tanks now reads zero.
I'm assuming that the tank which was partially full leaked out.
Is this something that can be connected in some way to the sub-zero weather or just coincidental? Can tanks leak like this because of extreme cold? If so, any precautions to be taken?
First time having LP so I'm not sure which way to go on this. I'm guessing that one of my stops once the weather warms and I'm back on the road will be to the local propane dealer to have the tanks serviced, but I sure would like to know what's going on and what to expect.
define cold.
propane won't gas/vaporize, below a certain temp.
at 30 below you can tell the content level 50 feet away by the frost line...
Quote from: eagle19952 on January 02, 2018, 03:37:32 PM
define cold.
propane won't gas/vaporize, below a certain temp.
at 30 below you can tell the content level 50 feet away by the frost line...
Been as low as -10 F this week. Today ranged from -4 F to a high of 5 F.
It definitely sounds like you have a leak - that's why they put the odor in there - so you will know when it is leaking. One possibility is a valve with a very slow leak which refrigerates the valve, shrinks it and effectively "opens" the valve further. Or a similar process on a fitting somewhere.
The "right" way to test it is to pressurize the system with compressed air and start looking for leaks. Personally I'd probably wait for warm weather, buy some propane and use the system pressure to test it. Either way you need to find the leak.
The system was filled in the warmer weather. Did a leak test and could find nothing leaking. I've been around the bus regularly and haven't noticed anything until this week when the smell became apparent.
The tanks are 30-pound horizontal tanks.
Can the extreme cold weather cause a leak to start that wasn't there during warmer weather?
This is what they look like right now. The top tank is the one that was partially filled until this week. There were absolutely no leaks that I could find prior to this.
I'm a little (okay, a lot) concerned about this. Not so much for the safety issues, as I know enough not to use the things until this is resolved. More so I'm concerned that if they need replacing I won't be able to replace with similar tanks. I don't see anything out there that's for sale now that has 30-pound capacity, is horizontal, and has the fill valve and access ports on the end. Maybe I'm panicking early - don't really know. But, I do know that I'll need to get these taken care of before hitting the road for our early season trips since the only heat is LP.
(https://uploads.tapatalk-cdn.com/20180103/f6e3e8e2994987a75a9e8db151adb4b1.jpg)
Richard
1974 GMC P8M4108A-125 (Current bus)
1964 GM PD4106-2412 (totalled Sept 2017)
Located in beautiful Wisconsin
KD9GRB
The cold works on propane pressure backwards:
"Propane pressure is directly related to the ambient temperature. For example, any volume of propane contained in a propane tank at 80 degrees Fahrenheit, the pressure is about 128 psi, at 50 degrees Fahrenheit, the pressure is about 78 psi and at zero degrees Fahrenheit, the propane pressure can reduce to 24 psi."
Looks pretty easy, haul those tanks out and trade 'em in for younger ones with fresh seals and fittings.
They look like regular forklift tanks?
happy coaching!
buswarrior
Its unlikely there's anything wrong with the tanks. They don't spontaneously develop leaks. The most likely culprit is the onboard plumbing followed by the tank valves and fittings. And yes, the cold could bring on a leak. Metal shrinks when it gets cold and once a leak starts the gas evaporating refrigerates the leak location which tends to make it worse.
This is the fill valve, and this is where the gas is leaking. Not sure how it's supposed to work, but right now the pressure is so low that I can easily push the center of the valve to release the seal by hand. Is there anything that keeps the seal pushed out other than the pressure of the gas? Is there supposed to be a spring in there? Either way, I'm wondering if the super low temps didn't reduce the pressure enough to cause this valve to let loose enough that the remaining LP seeped out. Maybe it wasn't as full as I thought it was. Either way, if it is the valve then I'm seeing them online for only about $15 each. Shouldn't be that tough to change out from the looks of things. Maybe someone else has had to do this?
(https://uploads.tapatalk-cdn.com/20180103/2610dc3e9e59238675c8d08d7e1ca7f4.jpg)
Richard
1974 GMC P8M4108A-125 (Current bus)
1964 GM PD4106-2412 (totalled Sept 2017)
Located in beautiful Wisconsin
KD9GRB
It would be easy to replace them with 2 upright 30 pounders that can be taken to the propane retailer with the towed for refills. It is on my list to yank out my built in tank and use the space for portable cylinders. Driving the bus to get propane can be a hassle. Taking the cylinders with the towed while camped without moving the bus would be much easier.
If you want to retain your current set up, just take it to someone that can replace the valves and re certify them.
JC
I'd go with changing out the tanks followed by a visit to the local fire house. The FD will have sniffers to spot propane leaks and probably will welcome the chance to train with them----of course if they find a leak they will insist you fix it and they'll want to check it again. Can't get any better (or safer) than that. Jack
Due diligence?
Local propane regulations?
Many jurisdictions have regulations regarding age since last pressure test and re-valved.
edit: Those are not built in tanks, they are portable tanks, same as go on forklifts, etc. important to not get vapour and liquid feeds mixed up, and must be mounted in proper configuration, up and down are critical for not feeding a slug of liquid into a vapour system. end edit.
Here in Ontario, beyond 10 years, vendor is not allowed to re-fill, and being portable tanks, they would have to be removed from the coach to be filled.
Of all the DIY available to do on a bus conversion, repairing a leaking propane tank may be better left to the pros?
happy coaching!
buswarrior
We've got a good propane vendor in town, and a visit to them is on my list. I'm seeing filler valves all over the internet, so I'm going to assume that in theory they can be changed. I'll let them advise the best way to go about this, if it's actually necessary. The fact that it was all sealed up tight as a drum till the recent cold snap has me wondering exactly what the cause is.
From what I've been able to read online about certification, etc., it seems that permanently mounted horizontal tanks don't have the same re-cert requirements as portable tanks. I'll confirm that at the propane store as well. They (I assume) will be able to at least start the conversation with the photos I've got and at least be able to give me an idea of what the options are.
I'll have them do the work if necessary. Otherwise I'm not afraid of doing basic work on LP plumbing if they say it's a DIY project. I'm hoping that they just let me know about some common weather-related problem or the like.
I thought about changing out the horizontal tanks for a pair of vertical, but that would require a lot more re-plumbing to move the regulator and get the hoses to the tanks. I'd also have to remove the tanks each time they needed filling. Since we do not have a towed vehicle with us, it won't add any convenience since our only way to get the tanks filled is to drive the bus to the filling station. With two 30-pound tanks we should be able to go at least through a weekend on a fill, so I'm hoping to fill the LP when we fill the diesel and/or when we empty the black tank.
Richard, I had the same thing happen on the main tank in our coach last winter (horizontal). We only use the main tank as a backup and use the 10 gal portable as the main. There are 2 'O' rings in that filler valve and the inside one dries out and shrinks when it's old and cold. You can buy a kit for it--but don't waste your time. The valves just screw in and out and they're readily available at your LP dealer or Ebay. I bought one on Ebay for @14.00 free shipping. The socket to replace it cost me $28.00 bucks. Took all of 2 minutes to replace using teflon tape. You definitely need the right socket though because you can't get on it properly with anything else. And you're absolutely correct, horizontal tanks aren't included in the Overfill Protection Device law that requires 12 year inspections. We discovered ours was leaking when I was out shoveling snow. I thought the sewer had frozen and backed up. Unfortunately, we had an almost full tank (naturally) so what we did, and I DO NOT RECOMMEND THIS :o is we switched to the leaky tank and used it for almost 3 months until it was empty. Not sure what else we could have done short of opening it and just blowing it off. Anyway, we're still here so obviously it worked for us. Of course, we didn't have any neighbors at the time so we didn't have to worry about smokers, etc.
HTH Will
They do look like regular forklift tanks and can be easily replaced if needed.
When you tested the propane system did you do a pressure drop test?
It is where they pressure the LP system and have a pressure gauge attached and let it sit for certain time frame to see if there is even a small leak somewhere and the pressure drops on the system.
You've got a lot of systems that are showing their age. You recently repaired furnace. Just exchange or repair tanks and regulator too. Those are cheap and diaphragms get old and leak. After doing this, you could can then move on to the next system that breaks down due to age. Just part of having an older conversion. We'll, just part of having any RV.
Spend a little money and have the system checked and updated if necessary. You don't want a leak and then have some ignition source light up the propane with an explosion especially in that enclosed area. If you have a fire or explosion you will be changing more than just the tanks. Safety first when dealing with propane or gasoline.
I would replace them with two 40 pound portable tanks and an automatic switchover regulator. While you're at it, get an LP detector for inside which includes an electronic solenoid shutoff.
Those tanks look like standard forklift tanks..
The only way to fill them is standing vertical out of the vehicle.
I don't think there is a vapor valve either, most are a liquid tap.
Move on and install a proper permanent vapor tank designed for a RV.
They look like forklift tanks. I had a problem with mine last year in that it was 25 years old and had to be recertified. I use it for my generator at the house. I took it to the people that test tanks(propane, oxygen ,acetylene) and thet inspected it and recertified it.I think is was about $25. Your tanks probalby either need recertifing now or will in the near future so I would take them to the tester, tell him the problem and they can replace the valves if necessary. The process for inspection involves taking off all the valves and fittings and inspecting the inside with a camera. That way you can be sure of what you have. Propane is great. I have it in my bus and did have a truck on propane. The generator runs on propane as well and is better than gas (or diesel) in that it doesn't go stale when not used for a long period of time. But, like gasoline, you have to treat it with respect.
Just got back from the propane dealer in town, one that I trust.
The valve is apparently leaking. Obviously it shouldn't be. Once the weather warms to the point I can work outside for at least a few minutes (still in single digit temps here) I will pull the two tanks and take them in for repair/inspection/etc. I'll bring the regulator along with me so that it can be inspected as well.
If necessary, I will replace with something else. By the way, these tanks do have a vapor tap and based on how the plumbing is connected I'd guess were designed to be refilled in place (not removed for filling). Not sure how that worked, and not sure if it can still be done that way.
I suppose that the two horizontal tanks could be replaced with two vertical tanks if necessary. I'll have to take measurements to be sure and bring them along with me when I take the tanks in in case we go that route.
Oh - the joy of old machinery! If I didn't love it so much this would be a real pain.
I have a permanen t 50 gal propane tank in the bus. Its filled with a hose designed for cars/trucks. Works fine but if I had to do it over I would put in 2 vertical tanks that you can remove for filling.Also I see one of the tanks has a solid copper line and the other has a rubber hose.I would replace the copper line with hose.Less chance of cracking.
That would also allow you to pull both tanks out for filling. Pretty hard to get the connection with a solid line.
There is no need to re-configure your tank install and change to vertical tanks.
Those "forklift" style tanks that you already have can be either/both liquid or vapour delivery while lying on their correct side. The pipe plug in the picture is where the other valve would be installed.
There is internal piping that is bent to feed from the appropriate side of the tank. That is why mounting orientation is very important.
The level indicator is a float arrangement that rides on the liquid, and gets you pretty close to knowing...
These on-the-side tanks are a blessing for a busnut. Tightly packaged, free access to the fittings, easily visible tank gauge.
For the fastening clamp, fabricate yourself a large wingnut with a large washer welded to the bolt head, and they'll pop right out when it comes time to fill/service/exchange.
happy coaching!
buswarrior
Quote from: buswarrior on January 03, 2018, 03:14:45 PM
There is no need to re-configure your tank install and change to vertical tanks.
Those "forklift" style tanks that you already have can be either/both liquid or vapour delivery while lying on their correct side. The pipe plug in the picture is where the other valve would be installed.
There is internal piping that is bent to feed from the appropriate side of the tank. That is why mounting orientation is very important.
The level indicator is a float arrangement that rides on the liquid, and gets you pretty close to knowing...
These on-the-side tanks are a blessing for a busnut. Tightly packaged, free access to the fittings, easily visible tank gauge.
For the fastening clamp, fabricate yourself a large wingnut with a large washer welded to the bolt head, and they'll pop right out when it comes time to fill/service/exchange.
happy coaching!
buswarrior
I agree - there are two taps on these and one is clearly labeled as 'vapor'. I hope that the propane dealer is able to get the valve changed out and fill the tank. He was only going from photos at this point, but he did indicate that it would be possible to do the necessary work without issue. He was unwilling (of course) to be committal at this point since he hasn't examined the tanks for safety issues though. I'll pull the tanks once I can stand to be outside long enough to do it.
Do you think I'll have any problems with the regulator? I was considering having it swapped out while I've got things apart. Same with the hard copper line on the upper tank. Makes more sense to me to have a flex rubber line on it.
I have an 8 foot flexible hose on the auxiliary tank so I can lift it out of the bay before having to disconnect, but that one is upright making it impossible to access the valve without removing it. I also have a length of rubber hose connected to the blow off port and routed down through the floor in the bay because like Bus Warrior stated, LP increases in pressure with higher temps and if it's going to blow off, I want that gas going outside.
Good luck with your project, Will
You can buy an auxiliary fill port adaptor which solves your problem. It has a female large Acme thread on one end which screws on to your ACME fill port, and a check valve similar to the one that is leaking, then a male ACME thread the same as your fill port.
Could be a permanent fix for your problem.
Definitely get rid of that copper tube! I had my local propane dealer make me some high-pressure hoses from Parker 7132 hose with crimped-on fittings, and I have some MB Sturgis 5LPN quick-connect gas fittings on the unregulated high-pressure side. I've protected all the HP hoses inside split-loom, and I put a marine stainless louver vent in the propane compartment's door to ensure that any vapor dissipates safely.
John
I got the two tanks taken to the propane dealer today. The tech said that they are in need of updating (and of course repair to the leaky valve). They are still in good condition overall and will not take too much to get up to snuff so that they are safe to continue using. After the repair/upgrades they'll fill them so I can just reinstall and be done.
Regarding the hoses/regulator...
The propane dealer sent me to another shop in town that does LP equipment, hoses, etc. I'm going over there on Thursday to have two new hoses made up to the correct length to replace the current rubber hose and the hard copper tube. I'll also upgrade to a new 2-stage regulator.
After all this things should be good to go. Sure is nice to have local shops that can get this stuff taken care of.
Keep ion mind that when full those tanks are heavy and it appears as though you will have to lift them to mount them.You might think of putting them in empty and then getting them filled.
Here, filling those tanks you are taxed with road tax (yeah, forklifts regularly drive on roads here ???). May not be a significant amount, just burns me to pay yet another unjustified tax. They are filled via a pump that looks like a regular gas pump used for filling propane powered vehicles, thus the road tax.
What chaps me with the people that exchange bottles like the Blue Rhino sold about everywhere you pay a high price thinking you are getting 5 gals and you only get 4 gals at 5 bucks a gal,where I pay under 2 bucks a gal at my dealer.
Some places here in the US will try and hit for road taxes too if you have a chassis mounted tank,I got into with a station in NM and told him to take his propane out and I would go else where I was not going to pay road taxes
Quote from: luvrbus on January 18, 2018, 03:46:22 AM
What chaps me with the people that exchange bottles like the Blue Rhino sold about everywhere you pay a high price thinking you are getting 5 gals and you only get 4 gals at 5 bucks a gal,where I pay under 2 bucks a gal at my dealer.
Some places here in the US will try and hit for road taxes too if you have a chassis mounted tank,I got into with a station in NM and told him to take his propane out and I would go else where I was not going to pay road taxes
But where was he going to put it once he got it back out? ;D
Quote from: PP on January 18, 2018, 08:43:44 AM
But where was he going to put it once he got it back out? ;D
Being the nice real guy I am I told him where he put it
Tanks repaired, updated, tagged, and re-installed.
LP dealer installed new relief valves, fill valves, and POL valves. I installed a new two-stage regulator and had new rubber hoses made to connect the tanks.
A bit of information I gathered in the process, which should apply throughout the US (if what I told was correct)...
There are two type of tanks in use - DOT and ASME. If the tanks are mounted permanently in a horizontal position AND they are ASME tanks, they do not require certification. If they are DOT tanks or not mounted in a permanent position horizontally then they require certification after 12 years. After that, they require re-certification every five years. The relief valves are good for ten years once replaced.
My tanks were permanently mounted and horizontal, but they are DOT tanks and not ASME. Therefore they require certification. The relief valves have never been replaced, so those were overdue. Leaks were found in the fill valves as well as the POL (output) valves so they were all replaced.
Each tank holds 33 pounds, or just over 7 gallons liquid. Total cost today for the refill and all the replacement parts (installed on tanks) was only $185. I paid another $60 for the two rubber hoses and regulator. All said and done, it's pretty reasonable to have two safe tanks in place, filled and ready to go.
For anyone interested, the tanks weighed in at around 70 pounds each when filled. Not the lightest things around, but still manageable.
(https://uploads.tapatalk-cdn.com/20180119/846081568af1409664d9e378d1024ced.jpg)
The discussion comes up here sometimes between the DOT and ASME tanks and it will surprise you how many do not know the difference, same with the people filling the tanks
Quote from: richard5933 on January 19, 2018, 09:47:40 AM
Tanks repaired, updated, tagged, and re-installed.
My tanks were permanently mounted and horizontal, but they are DOT tanks and not ASME.
Richard, are you sure that's correct?
Will
Pretty sure. DOT is stamped into the upper guard ring.
Unless you are asking about something else. In that case, I may not have a clue.
Quote from: richard5933 on January 19, 2018, 03:54:51 PM
Pretty sure. DOT is stamped into the upper guard ring.
Unless you are asking about something else. In that case, I may not have a clue.
Sorry, I should have been more specific. You said they'er permanently mounted, but they look removable for servicing. My bad :(
If you're talking about permanent installation, then you are correct in a way. There is always going to be a debate as to what constitutes permanent, since it really just depends on how many nuts & bolts someone is willing to remove. I don't think I've seen an ASME tank in a horizontal position that wasn't bolted in place. In my case, since the tanks are DOT tanks, it really made no difference. Permanent or not, a DOT tanks need to be re-certified on a regular schedule.
The cost for the re-certification was only $5/per tank. Not that much at all. Five years from now I'll plan to do the same thing again - take the tanks for re-certification and refilling at the same time.
Speaking of mounting, the Custom Coach team did a really creative job of mounting these two tanks. They lay in cradles to keep them in place. At the back of the bay behind each tank there is a 1"-thick piece of wood cut to perfectly fit into the bottom ring on the tank (bottom, if the tank is standing up). As the tanks are slid into place in their cradles the metal rings mate with the wood blocks, and then only one bolt is necessary on the front ring of the tank to anchor into the cradle. Really couldn't be much easier to pull the tanks when needed for service. The addition of the rubber hoses makes it even easier as there is no longer any copper lines to get in the way.
ASME tanks are.250 wall (thickness) Dot tanks are .125 wall thickness,ASME tanks require a ASME certified welder DOT require no ASME certification and ASME tanks are stationary design not to be moved, a huge difference in the 2 tanks
http://www.propanetankstore.com/dot-asme-tank-differences/ (http://www.propanetankstore.com/dot-asme-tank-differences/)
ASME=
The American Society of Mechanical Engineers
That site left out Mechanical?
Lots of great information. Thanks for the links.
If I was to rebuild, I'd certainly opt for a tank that was ASME. I just looked through the 1974 Lee Cylinder catalogue that I found in the literature that came with our bus to see what tanks were available from them in 1974, and it looks like they did not carry any ASME tanks, only DOT certified. In looking at motor homes from 1974 I only see DOT vertical cylinders in use. There probably were ASME tanks around, but they must not have been all that common on the RV world yet.
Interestingly, all the accessories and house systems on our Custom Coach conversion seem to fall into a few categories: Anything roof vent related seems to have been pulled from the Airstream parts bins. Same for some of the interior light fixtures. Electrical systems and parts look to have been taken from Marine catalogues. Same for the generator. Interior was styled after vintage Airstream trailers with the laminated walls and rounded corners. The rest of things look like they used whatever they could find that would work, which is probably why we have these LP tanks that in every way look like they belong on a forklift and not an RV. LP dealer says that in their current configuration and use they are safe, so we'll leave them alone for now.
More busnuts that want portable tanks should consider those horizontal style 30 pounders.
Easier access to tank connections/less wasted space to do so, versus the lost volume of airspace in a bay that has to be left above a vertical tank so you can work the connections.
Don't have to move the coach to fill the propane.
Nice tidy package and accessible. Don't mess with success!!!
happy coaching!
buswarrior
Here on the river most of the boats have portable fiberglass propane tanks and they are starting to pop up on forklifts too
Clifford why do they have propane forklifts on the river?
Sent from my SM-N920T using Tapatalk
Quote from: Dave5Cs on January 22, 2018, 07:22:51 AM
Clifford why do they have propane forklifts on the river?
Sent from my SM-N920T using Tapatalk
Seems like all the Californians wreck their boats,Ski Doos and need a forklift to set it back on the trailers just a WAG