High pressure Cylinder use question

[carl37]

Bit of a grey area this one:-
In use, connected up to the regulator, should the cylinder be turned full on? I read somewhere that the spindle\knob should be turned on either full or closed. Cannot think of a reason for this?
Being lazy I often just turn the cylinder on a quarter of a turn. Is this wrong?

 

[Tiggy_dorset]

When I was working with acetalyne a few years ago, I used to crack it open about 1/2 a turn. It meant that the bottle could be closed quickly in an emergency. I dont know if that applies to non-flamable gases but out of habit I still only turn bottles on for 1/2 a turn. I have never had any issues.

I expect I am about to get slapped for that now

 

[Robotstar5]

I only turn on half a turn, it would take ages repositioning the bottle key as it will only swing a 1/4 turn at a time

 

[PhillipM]

If the valve is only cracked open the pressure drop across what is now a venturi can freeze the neck of the bottle in some circumstances.

 

[pedrobedro]

I only open co2 cylinders fully. I read somewhere that they only seal fully open or fully closed and can leak from the spindle if partially opened.

 

[gordon stephenson]

I believe some(or maybe all) cylinders in the USA have valves that require to be fully opened as the spindle has another seat at the top that must take the pressure off the gland arrangement,

 

[carl37]

Many thanks for your replies.

If the valve is only cracked open the pressure drop across what is now a venturi can freeze the neck of the bottle in some circumstances.

PhillipM, that is a very interesting reply, and maybe the reason my Regulator (Nitrogen system) gets so cold and condensates so much?

 

[backpurge]

Many thanks for your replies.



PhillipM, that is a very interesting reply, and maybe the reason my Regulator (Nitrogen system) gets so cold and condensates so much?

What flow rate/outlet pressure are you using

 

[Steve-O]

I only crack mine open half a turn as well.. are you suposed to keep turning untill it stops / fully open??

 

[carl37]

What flow rate/outlet pressure are you using

Outlet pressure just less than 1 bar, flowrate 15-20 litres per minute.

Steve I think half a turn is good. I don't think I've been cracking mine open even a quarter.

 

[Drains]

I open cylinders enough to get the gauges to fully register, and a bit. With acetylene the valve is opened as above and the key set so the valve can be closed in one movement, without removing the key!

 

[Shox Dr]

As Drains said; only open them enough to register the gauges.

I also leak test the valve and tap, on new bottles. It's frightening how many bottles leak from the key hole when opened. If so it goes straight back