jimmoore
Platinum Member
Bird, you can tell it's getting fall here, the wild winter onions are coming up along side the roads. What a stink when you bushhog them!
jim
Motor Home Propane Tank
- Thread starter johnjc
- Start date
gordon
Veteran Member
The most simple route to take is to get whats call an extend a stay.Here is an example of onehttp://www.metrorv.com/store/group.cfm?SubCategoryID=153 What that does is tap into the existing moterhome line with a high pressure rubber hose. That way you can use portable tanks. It's an approved hook up. Of course if you have any critters that might chew on the line its not a bad idea to cover it with foil or metal flex.
The problem using portable tanks is the size of the smaller tank. If you have a small propane tank you have a smaller wetted surface. What that means it it will freeze up faster at lower temps. So you could still have a third of a tank left in a twenty lb tank and can't get any gas out of it because the liquid is too cold to vaporize. Something to consider if you go with a DOT tank. The larger the better.
Even using the moterhome tank on a very cold night and the level is low in the tank, if it's not heated can freeze up. A light bulb near the tank cures that problem.
If you do the hook up yourself check for any leaks with an approved leak soap for propane. If none can be found in your area you can make your own home brew with some mister bubble. DO NOT use regular dish detergent!!! Reason is that it has amonia in it and what that does is break down the brass fittings causing stress cracks and leaks down the road. Take my word for it.
To answer your question in your post. Yes it can be done, I've done it many times working on R/Vs. Would I say it's safe to do it without the proper rig. HECK NO!!! Also all of the newer tanks have flow checks that you would have to bypass. Also 80% valves to trick. NO I won't tell you those tricks. Sorry.
hope this is clear I can go into it much deeper but you would just fall asleep reading it./w3tcompact/icons/smile.gif
any other questions just ask
Gordon
The problem using portable tanks is the size of the smaller tank. If you have a small propane tank you have a smaller wetted surface. What that means it it will freeze up faster at lower temps. So you could still have a third of a tank left in a twenty lb tank and can't get any gas out of it because the liquid is too cold to vaporize. Something to consider if you go with a DOT tank. The larger the better.
Even using the moterhome tank on a very cold night and the level is low in the tank, if it's not heated can freeze up. A light bulb near the tank cures that problem.
If you do the hook up yourself check for any leaks with an approved leak soap for propane. If none can be found in your area you can make your own home brew with some mister bubble. DO NOT use regular dish detergent!!! Reason is that it has amonia in it and what that does is break down the brass fittings causing stress cracks and leaks down the road. Take my word for it.
To answer your question in your post. Yes it can be done, I've done it many times working on R/Vs. Would I say it's safe to do it without the proper rig. HECK NO!!! Also all of the newer tanks have flow checks that you would have to bypass. Also 80% valves to trick. NO I won't tell you those tricks. Sorry.
hope this is clear I can go into it much deeper but you would just fall asleep reading it./w3tcompact/icons/smile.gif
any other questions just ask
Gordon
OP
johnjc
Bronze Member
- Joined
- Jun 30, 2001
- Messages
- 62
- Location
- Carlisle Pa
- Tractor
- Kubota L48, Case 580 tlb Case 530(sold), case VAC
Thanks everyone, for the replies, they helped a lot. Gordon can you tell me what are flow checks and 80% valves and what do they do?
gordon
Veteran Member
Ok here goes.
First the purpose of the 80% valve is to allow the person filling the tank a way of knowing that the tank is full. The reason to only fill a propane tank to 80% is because of the expansion that takes place relative to the outside temp.. As propane warms it expands as Bird has already said. So you take it from there. If the tank is overfilled there is a relief valve that will blow off if the pressure in the tank gets to high.
There are a few different styles of the so called 80% valve. Here are a couple of different types.
First on the D.O.T. tank old style valve---there is a tube that is attached to the valve that goes straight down into the tank to the point of 80%. This is a screw thats opened when filling on the side of the valve and when liquid hits the bottom of the diptube liquid will start to come out of the small hole in the valve. Filling is then stopped and the screw is shut on the tank.
Moterhome or asme tanks old style have the same setup as above but the valve is separate and is opened with your fingers when filling.
New style valves on the dot tanks have a float attached to the valve that once the 80% mark is hit it stops flow going into the tank, you still have the screw setup of the old style tank as a back up on the new valves. Double safety.
The new style asme tanks have the same setup with a float that stops the flow going into the tank as well. You still open the bleeder when filling as well.
Are you with me so far?
Now for the flow checks. There are a few different styles as well.
First old style pigtail on a moterhome or dot tank. The pigtail is the black rubber piece that attaches the lp tank valve to the regulator. If you remove the pigtail and giggle it you will hear a rattle in it. The rattle you hear is the flow check. If the pigtail was sheared off in an accident the check valve kicks in and flow from the tank is almost reduced to nothing. If you open your propane tank too fast you can sometimes hear the little click of the check. Same pigtail as on the moterhomes.
New style DOT tank has the flow check built into the valve itself for added safety. Some of the newer moterhome valves are the same as well with the flow check built into the valve itself.
Hope this was clear enough to understand
Gordon
First the purpose of the 80% valve is to allow the person filling the tank a way of knowing that the tank is full. The reason to only fill a propane tank to 80% is because of the expansion that takes place relative to the outside temp.. As propane warms it expands as Bird has already said. So you take it from there. If the tank is overfilled there is a relief valve that will blow off if the pressure in the tank gets to high.
There are a few different styles of the so called 80% valve. Here are a couple of different types.
First on the D.O.T. tank old style valve---there is a tube that is attached to the valve that goes straight down into the tank to the point of 80%. This is a screw thats opened when filling on the side of the valve and when liquid hits the bottom of the diptube liquid will start to come out of the small hole in the valve. Filling is then stopped and the screw is shut on the tank.
Moterhome or asme tanks old style have the same setup as above but the valve is separate and is opened with your fingers when filling.
New style valves on the dot tanks have a float attached to the valve that once the 80% mark is hit it stops flow going into the tank, you still have the screw setup of the old style tank as a back up on the new valves. Double safety.
The new style asme tanks have the same setup with a float that stops the flow going into the tank as well. You still open the bleeder when filling as well.
Are you with me so far?
Now for the flow checks. There are a few different styles as well.
First old style pigtail on a moterhome or dot tank. The pigtail is the black rubber piece that attaches the lp tank valve to the regulator. If you remove the pigtail and giggle it you will hear a rattle in it. The rattle you hear is the flow check. If the pigtail was sheared off in an accident the check valve kicks in and flow from the tank is almost reduced to nothing. If you open your propane tank too fast you can sometimes hear the little click of the check. Same pigtail as on the moterhomes.
New style DOT tank has the flow check built into the valve itself for added safety. Some of the newer moterhome valves are the same as well with the flow check built into the valve itself.
Hope this was clear enough to understand
Gordon