Jump to content
I Forge Iron

1 empty 1 full and frozen


pkrankow

Recommended Posts

Strange thing today. I took apart 2 pair of tongs I made and was unhappy with. Removing rivets is interesting. I reforged and reshaped them, and then my bottles froze.

I am using 2 20# exchange bottles manifolded together. They were about half full when I started, and since I was just forging I didn't set up a water bath. It is about 40F outside. The bottles were at a slight height difference to each other due to the slope of the drive. The empty bottle was uphill, and about 1 inch higher. The full bottle seems to have more in it that when I started.

I'm just confused as I expected the propane to be consumed evenly, and not apparently siphon from one bottle to the other.

On the plus side I only need to get 1 bottle filled.

Phil

Link to comment
Share on other sites


One turkey fryer regulator listed for 30-60psi, but capable of 0-60psi, after the tank manifold. The manifold has no regulation or check valves. It's basically a T. I got it through Zoeller forge.
Phil


So you have fittings that scew into each tank and then lines from the fittings to the manifold, then the regulator?

I get old gas grille regulators and tee them together. My Johnson, which is a gas pig will run on as little as 2 twenty pound tanks. At one time, I had 6, I think manifolded together with individual valves on the manifold, so I could change tanks without shutting off the forge (losing heat).
Link to comment
Share on other sites

Exactly FE, that's what I thought would happen too. One bottle was used to cook 1 meal on the grill, but the grill uses very little fuel compared to the forge, and that doesn't account for one bottle appearing to have filled, which is the confusing part. I don't know which bottle was used on the grill, as they are marked the same.

Arftist, that describes my setup well.

I want larger bottles, but can't justify the cost yet, nor transport larger bottles. Yes, I know buying bulk fuel is a better price than exchange. I have 2 bottles for the grill already, so for now they are for both the grill and forge.

Phil

Link to comment
Share on other sites

Did you have the bottles filled at different times or at different places? there is butane mixed with propane in the winter to help its freezing point. if the two bottles have slightly different mixtures this may account for the differing pressers.

second thought is there temperature. was one bottle in the sun and the other in the shade, or one closer to a heat source. if one bottle was wormer than the other then the pressure would be greatly higher and move from one to the other.

lastly some bottles have check valves that let the gas out only one way, and others have valves that let the gas travel both ways.

Link to comment
Share on other sites


So you have fittings that scew into each tank and then lines from the fittings to the manifold, then the regulator?

I get old gas grille regulators and tee them together. My Johnson, which is a gas pig will run on as little as 2 twenty pound tanks. At one time, I had 6, I think manifolded together with individual valves on the manifold, so I could change tanks without shutting off the forge (losing heat).



Hey what Johnson do you have? I have been having issues getting the fuel right to mine, with a 3/8 hose and small regulator even with the regulator open all the way I couldn't get enough fuel to it to get to a good forging heat... So I went to a big 1" regulator and 1" hose.. and now even with the regulator at 1 psi I melt steel.... My plan is to put a needle valve inline to create a secondary orifice but just curious what your using...
Link to comment
Share on other sites

The full bottle was downhill, and slightly closer to the forge, but I doubt that it was heated by the forge. I don't know about the sunshine, it was overcast. These are exchange bottles from the same place, at the same time, but could have been different fuel mixes deliver different weeks.

I am suspect about the check valve: how do they fill them?

I think the fuel mix difference seems most reasonable. I guess I will have to expect this to happen till I can get bigger tanks.

Link to comment
Share on other sites


Hey what Johnson do you have? I have been having issues getting the fuel right to mine, with a 3/8 hose and small regulator even with the regulator open all the way I couldn't get enough fuel to it to get to a good forging heat... So I went to a big 1" regulator and 1" hose.. and now even with the regulator at 1 psi I melt steel.... My plan is to put a needle valve inline to create a secondary orifice but just curious what your using...


I have a number 122 b. It was set up for natural gas but the folks at Johnson told me how to convert it to propane. Is yours propane or natural gas? What are you running it on? I think for natural gas it need a 1" inlet line. Propane inlet can be much smaller, mine is 1/2". I don't get anywhere near melting temp though. Wonder if you have a natural gas orifice but are fueling with propane?
Link to comment
Share on other sites

  • 3 weeks later...

What is interesting to me is the physics would tend to equalize flow out of the bottles. That is, as you draw out of one bottle, it cools down, and the pressure in the bottle goes down. If the other bottle had little flow, its temperature and pressure would remain the same, so it would have higher pressure, so most of the flow would then come from that bottle.

To put it another way, the tendency would be for the temperature (pressure) of the two bottles to equalize. If one bottle started out more full than the other, it would remain that way.

There may be something wrong with the one bottle or the manifold, preventing that bottle from delivering the high flows needed for a forge. The bottle might still work in a lower flow application.

One thing to remember is that there are safety features in bottles and regulators to shut off flow when it senses very high flows. Perhaps that safety feature got tripped in the bottle which did not empty. One way to reduce the risk of tripping that feature is to open the tank valve slowly, and then later turn on the flow to the forge. I have been caught by this more than once, generally when I am in a hurry and open the tank valve quickly. The safety will reset if you close the valve for a time, and then reopen it slowly. When this feature is tripped, the flow is almost cut off, but enough flow remains to allow pressure to equalize and for the safety to reset.

A simple experiment would be to shut off the tank that is almost empty, and see if the other tank will deliver enough propane for your forge to operate correctly.

I found this little item on the web, which might also apply.

Q: Roofers and other commercial customers are trying to use OPD equipped tanks on torch applications and they are not getting an adequate flow through the valve. What can we do about this?
A: Some of the early OPD valves had an insufficient flow capacity for certain types of service such as high pressure torch applications. Market competition has resulted in OPD's becoming available that have significantly greater rates of flow.

Richard

Link to comment
Share on other sites

I have been already opening the bottles with the gas shut off at the forge. I did not expect it to be the flow safety in the OPD, but was aware of its existence. I put the full bottle in a bucket of water and had no problems with it. I checked the manifold for obstructions and there are none, the tubing is clear.

Both bottles are now empty, so I need to refill or exchange them.

Phil

Link to comment
Share on other sites

It gets worse---we don't have natural gas where we live so my wife finally broke down and got a propane kitchen stove---now when it's 100# bottle gets empty she robs my forge of it's 20# bottle to use until I can get the big one carted into town and re-filled. What we will agree to to keep the meals coming!

Link to comment
Share on other sites


Strange thing today. I took apart 2 pair of tongs I made and was unhappy with. Removing rivets is interesting. I reforged and reshaped them, and then my bottles froze.

I am using 2 20# exchange bottles manifolded together. They were about half full when I started, and since I was just forging I didn't set up a water bath. It is about 40F outside. The bottles were at a slight height difference to each other due to the slope of the drive. The empty bottle was uphill, and about 1 inch higher. The full bottle seems to have more in it that when I started.

I'm just confused as I expected the propane to be consumed evenly, and not apparently siphon from one bottle to the other.

On the plus side I only need to get 1 bottle fille

Phil





I used to work for a propane company and propane will go to the lowest point down,where as natural gas will flow to the highest point. We would pour propane gas out of a coffee can like water. We would pour natural gas to a coffee can held over the lower can. Now back when OSHA was not such a pain the propane gas would be ignited in the bottom coffee can and natural gas would be ignited in the coffee can held open end down just to prove the point. The tempature being 40 degree and the proper humidity could be the reason the propane went to lower cylinder. The humidity will cause a propane cylinder or tank to sweat and it is possible to guage how much liquid gas is in the tank by sweat ring around the tank.
Just a little two cents to add to the confusion
Link to comment
Share on other sites

I used to occassionaly have problems with small tanks not allowing propane to flow from the tanks. The new style valves(should be pretty much on all/most small tanks by now) tanks have a safety valve that will not allow gas to free flow if it detects what it determines is an unrestricted flow of propane. Testing for this is as simple as cracking a valve open with no restriction on the gas flow (don't do this test inside please). If the safety valve is working, it will not let much (or any) gas out before it closes the opening off inside.

When I'm finished forging, I always shut off my gas with the tank valve, so the hose is not left under pressure. Sometimes I could not light the forge the next time I tried because the safety valve would clamp shut when I opened the tank valve (that free flow thing). When I started using needle valves at the forge, I would crank the needle valve down before I opened the tank valve. After the tank valve was open (and the hose was pressurized, I would open the needle valve just a little and start the forge, then open the needle valve till I had the flame I wanted.

Later, I added a shutoff valve at the end of the hose at the forge. I still use the tank valve when I shut off the propane so the hose isn't pressurized, but before I start the forge, I close the shutoff valve near the forge. When the tank valve is opened, it pressurizes the hose and doesn't close the safety valve in the tank. Then I crank the shutoff valve open a little and start the forge. After the forge is burning, I open the shutoff valve all the way. This way... I don't need to adjust the flame (with the needle valve) every time I start the forge.

Unless you are already using a shutoff valve at the forge, I suspect one the safety valves on your tanks is clapping shut when you open the tank valves. I've had the problem (before I started using shutoff valves) with both single and dual tank setups. I still use single and dual tank setups and have never had the problem you describe after I started using shutoff valves.

WHEW.... that was a mouthful...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...