OP
dinogep
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I will ask the type of cylinder next time I go there to get my tanks filled again. Probably around the end of this week.
burn marks inside alu tank
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I have used that video for years in training employees. At least two of the local gas suppliers have used it as well.
Dale
hydro testing
Dale
hydro testing
Frank,
To what would you attribute the scorched seats? Turning the valve on too quickly, valve design, or something else? I know some valves deliver gas very quickly even when the knob is slightly turned. Others seem to deliver directly relative to the number of turns. I'm asking as I have a mixture of valves on my bottles.
Cheers,
Couv
..(he assumed, that since it is brand new, oxy cleaning is not really necessary before the filling)...
Bad assumption, as you've already heard.
, and afterwards the O2 smelled really bad (a bit like chlorine).
Valve seats, when they burn, break down into a variety of nasty chemicals, principally chlorine, fluorine and oxygen.
We suspected the tank valve seat, but after dismounting the tank the seat looked intact.
Sometimes valve seats don't "burn" in the classic sense, instead they ablate. Think space ships and heat shields - they just erode in a poof of plasma and smoke. Unless you know what you're looking for, it's easy enough to not see the damage. There won't necessarily be any discoloration or distortion of the remaining material, just less of it.
On the inside of the tank however there were black patches (soot?), so we now think that the smell was caused was some contamination on the inside of the tank wall.
Possible. Most hydrocarbons don't die smelling like chlorine, however. Another alternative would be that the flash caused the interior surface of the cylinder to oxidize.
Is it possible that something during the manufacture contaminated it (so his assumption about the cleanness of the new tank was wrong), or should we suspect that it was not as brand new and unused as stated by the seller?
Yes, to both theories.
And now you know why assuming something is oxygen ready is a bad idea. You're never going to know for sure what happened but my guess would be that the cylinder was filled too quickly and that the combustion started at the valve seat, with the combustion residue forced inside the vessel. There, the heat might have ignited other contaminants but more likely what you're seeing is a little corundum on the walls from the flash. Could have been worse. Much worse.
A question for you: what do you do with a cylinder that has been exposed to fire? Especially one that has either been hot enough to burn off contaminants inside the cylinder or hot enough to oxidize the walls themselves? Ruhroh...
Bad assumption, as you've already heard.
, and afterwards the O2 smelled really bad (a bit like chlorine).
Valve seats, when they burn, break down into a variety of nasty chemicals, principally chlorine, fluorine and oxygen.
We suspected the tank valve seat, but after dismounting the tank the seat looked intact.
Sometimes valve seats don't "burn" in the classic sense, instead they ablate. Think space ships and heat shields - they just erode in a poof of plasma and smoke. Unless you know what you're looking for, it's easy enough to not see the damage. There won't necessarily be any discoloration or distortion of the remaining material, just less of it.
On the inside of the tank however there were black patches (soot?), so we now think that the smell was caused was some contamination on the inside of the tank wall.
Possible. Most hydrocarbons don't die smelling like chlorine, however. Another alternative would be that the flash caused the interior surface of the cylinder to oxidize.
Is it possible that something during the manufacture contaminated it (so his assumption about the cleanness of the new tank was wrong), or should we suspect that it was not as brand new and unused as stated by the seller?
Yes, to both theories.
And now you know why assuming something is oxygen ready is a bad idea. You're never going to know for sure what happened but my guess would be that the cylinder was filled too quickly and that the combustion started at the valve seat, with the combustion residue forced inside the vessel. There, the heat might have ignited other contaminants but more likely what you're seeing is a little corundum on the walls from the flash. Could have been worse. Much worse.
A question for you: what do you do with a cylinder that has been exposed to fire? Especially one that has either been hot enough to burn off contaminants inside the cylinder or hot enough to oxidize the walls themselves? Ruhroh...
Tigerman
Contributor
OP
dinogep
Registered
I've asket: the tank was a luxfer one.
OP
dinogep
Registered
"And now you know why assuming something is oxygen ready is a bad idea. You're never going to know for sure what happened but my guess would be that the cylinder was filled too quickly and that the combustion started at the valve seat, with the combustion residue forced inside the vessel. There, the heat might have ignited other contaminants but more likely what you're seeing is a little corundum on the walls from the flash."
The valve seat was taken out and it had not only the looks but also the "feel" of an intact one. I suppose the burning that emits enough combustion products to be seen on the tank walls would at leas make the surface porous or leave there something that can be rubbed off.
By the way: how much Si is there in the alloy of the tank? I have oxidized a lot of Al both in a slow and in a very fast way, but have not seen the black of SiC
"A question for you: what do you do with a cylinder that has been exposed to fire? Especially one that has either been hot enough to burn off contaminants inside the cylinder or hot enough to oxidize the walls themselves?"
Depends on the amount of contaminants burned. A very small amount cannot produce enough heat to raise up the walls in depth.
The valve seat was taken out and it had not only the looks but also the "feel" of an intact one. I suppose the burning that emits enough combustion products to be seen on the tank walls would at leas make the surface porous or leave there something that can be rubbed off.
By the way: how much Si is there in the alloy of the tank? I have oxidized a lot of Al both in a slow and in a very fast way, but have not seen the black of SiC
"A question for you: what do you do with a cylinder that has been exposed to fire? Especially one that has either been hot enough to burn off contaminants inside the cylinder or hot enough to oxidize the walls themselves?"
Depends on the amount of contaminants burned. A very small amount cannot produce enough heat to raise up the walls in depth.
My take, on whatever I'm going to talk about this time
is that the receiving vessel have it's valve fully open
seats be of a conical design and that the slumping
of grease compatible or not is not condusive to
minimising heat even with kid glove cracking
is that the receiving vessel have it's valve fully open
seats be of a conical design and that the slumping
of grease compatible or not is not condusive to
minimising heat even with kid glove cracking
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The one I tend to burn up most often is the line valve that is a part of the booster. This valve is never opened or shut, but is left in the wide open position all of the time. I have learned to leave a valve disk in it without a teflon insert. Since I don't use the valve, the disk doesn't do me any good, anyway. I would say that the reason it burns up is the flow going through the booster. It's a masterline 7000-2. All of the flow of the booster goes through that valve, where we put up to 5 bottles on to fill, there is much less flow through the whip valves, which are the same valves.
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