How far do I open the bottle?

[BrokenBiker]

got a 20 litre bottle of argoshield light, it has a little square peg to open the valve with...

How far do I need to open it once the reg is on?

 

[gordon stephenson]

Usually around 1/2 a turn, or as just said enough to give you the. Flow you require.

 

[eSCHEn]

1/4 turn past the crack point. Leave the key in so than you can just pull it down and it's off. Guess that's what you do when you learn on OA lol

 

[Tom Orrow L]

Looks like i'm opening mine way too much then lads

 

[eSCHEn]

Looks like i'm opening mine way too much then lads

Don't think it matters really on inert mate. It's just when the gas is explosive you're looking for all ways to reduce risk

 

[BrokenBiker]

1/4 turn past the crack point. Leave the key in so than you can just pull it down and it's off. Guess that's what you do when you learn on OA lol

I haven't got a key...well not yet anyway

 

[Paul.]

A quarter to a half of a turn should be enough, you want to be able to turn it off in one movement, ie without having to re position the spindle key.

 

[Bill Edwards]

It's pretty obvious when the gas is coming through...

 

[BrokenBiker]

right well i found a key that fit, cracked it half a turn, set to 10LPM and i must say, it beats teh hell out of gasless...

 

[brightspark]

oxy acet less than quarter of a turn is enough

 

[tommullin]

someone told me, or I read somewhere that gas bottle valves seal at fully closed and at fully open. so to prevent leakage, it needs to be fully open or fully closed? is that not true? I guess providing your reg can take full pressure from the bottle its wouldn't do any harm to open it fully? or are there safety issues? My bottles have a hand wheel operated valve, not a key if that makes any difference?

 

[BrokenBiker]

someone told me, or I read somewhere that gas bottle valves seal at fully closed and at fully open. so to prevent leakage, it needs to be fully open or fully closed? is that not true? I guess providing your reg can take full pressure from the bottle its wouldn't do any harm to open it fully? or are there safety issues? My bottles have a hand wheel operated valve, not a key if that makes any difference?

as soon as you have cracked the valve off the reg has got the full pressure of the bottle...my reg is currently reading the bottle content pressure as just over 200 bar...and that just under half a turn...

i think there are safety issues with a fully open valve as if anything starts to go wrong for any reason you have got a lot of effort to close that valve quickly...i can close mine with a single turn of the hand if needed

 

[tommullin]

that's true - you get full pressure but a throttled flow rate - so probably just a colder regulator with partially open valve

if anything starts going wrong, ill be running not closing a valve to save £70 of argon!

 

[tommullin]

what about opening valves slowly to prevent damage to the diaphragms in regulators? is that one true?

 

[BrokenBiker]

that's true - you get full pressure but a throttled flow rate - so probably just a colder regulator with partially open valve

if anything starts going wrong, ill be running not closing a valve to save £70 of argon!

70 quid? where do you buy your argon? ive just got 20 litres at 200-something bar for 35 incl VAT...also, id be more concerend with the bottle causing damage to other things rather than saving the argon...200 bar will do some damage when it send a bottle belting around the place

 

[cumbriasteve]

what about opening valves slowly to prevent damage to the diaphragms in regulators? is that one true?

I simply give mine a quarter turn without any thought to doing it slowly, never had a problem with the regulator.

 

[BrokenBiker]

I simply give mine a quarter turn without any thought to doing it slowly, never had a problem with the regulator.

when i got my reg connected i found one of those universal keys for radiators and electrical panels that had the right sized key on it...it was that tight there was no way i was opening it slowly...once it cracked off i had turned it half a turn without realising it...

 

[tommullin]

Argon or Argo-shield? ive not bought either for a while, but it sounds like I might be paying over the odds!!!

My main concern with 200 bar is self preservation!

I must have wasted countless seconds over the years cracking vales slowly and opening them fully! cheers for the info! funny what you read and accept as gospel but never challenge...

 

[AdrianH]

I usually give mine at least one full turn. Give it a crank open, connect your reg and open the reg to your desired LPM .

Sorry the above just made me giggle a bit with the order of things.

Adrian

 

[addjunkie]

If there were safety issuse with a fully open valve, they would not supply it like that. Even with a big warning sign the size of the bottle the supplier would still be liable. Once the valve lifts off its seat, the unwound regulator is exposed to full pressure.

Full flow is achieved through a valve when its seat has lifted 1/4 of its diameter. By cracking the valve if the regulator is fully open the pressure drop is accross the bottle valve, cooling due to jule thompson effect will be obsereved. But by only cracking the valve you run the risk of damaging the valve seat, and possibly end up loosing your precious argon trickling into your workshop.

The regulator is designed to control the pressure drop from the bottle to the user, not the bottle valve.