hi guys, i am using propane on my changeover system. when it changes over there is still gas comming out of the valve. when i shake the container i can hear liquid slopping about inside. my question is, is the container empty? if it isint how can i tell when it is? thanks for any help. geoff
gas
- Thread starter geoff_5040010
- Start date
Damian
Moderator
Geoff, it is very unlikely that you will ever end up with a totally empty cylinder.
You will have used all the usable gas, but be left with the "heavy ends" as they are called still inside the cylinder, which are only burnt off when the cylinder goes for its testing and cleaning.
You will have used all the usable gas, but be left with the "heavy ends" as they are called still inside the cylinder, which are only burnt off when the cylinder goes for its testing and cleaning.
Geoff,
If you have the automated changeover system, then the effect you see is the tolerance on the change over valve "deciding" that the bottle is empty.
As the bottle gets very close to empty, evaporation of the remaining liquid into gas can no longer sustain the normal 16 bar (approx) of pressure - and the valve will flip over.
It's not really due to "heavy ends" - because in Propane, the only other major component is around 1% of Butane - and that's a gas too at room temperatures. There will be parts per thousand or million of higher hydrocarbons - like Pentane - but these also boil off very easily - until you really get to the "heavy ends" - Hexane and above. But in a 5kg bottle, there should only be a drop or two of heavy ends left behind (rather less than 1 ml - and not enough to slop around in the bottle)
Robert
If you have the automated changeover system, then the effect you see is the tolerance on the change over valve "deciding" that the bottle is empty.
As the bottle gets very close to empty, evaporation of the remaining liquid into gas can no longer sustain the normal 16 bar (approx) of pressure - and the valve will flip over.
It's not really due to "heavy ends" - because in Propane, the only other major component is around 1% of Butane - and that's a gas too at room temperatures. There will be parts per thousand or million of higher hydrocarbons - like Pentane - but these also boil off very easily - until you really get to the "heavy ends" - Hexane and above. But in a 5kg bottle, there should only be a drop or two of heavy ends left behind (rather less than 1 ml - and not enough to slop around in the bottle)
Robert
Facebook
Twitter