Regulator jumped from 12 to 30+ lpm

[skotl]

I've been ignoring earlier advice and just left the reg set at ~12lpm, on a BOC Y argoshield light cylinder.
After use I always push the valve closed and leave the reg open.

Today, I opened the valve at the usual amount (around 1/4 turn) and the reg piiiinged - unusual noise so I checked the lpm and it was 30+. I pulled the trigger and it was still at 30 with gas flowing.

The reg shows that the bottle has around 1/4 content left.

Am I just Doing It Wrong(tm) and should be closing the reg off each time, or will the reg change its flow based on how much gas is in the cylinder?

 

[rikrobson]

I turn the gas off and leave the reg on and its always been fine. A single stage reg will increase flow as the cylinder pressure drops, but I don;t think to that extent.
It could bed a fault in the reg. does it still adjust?. I'd just change the reg to the correct pressure and check the flow with a pea shooter gauge.

 

[skotl]

I turn the gas off and leave the reg on and its always been fine. A single stage reg will increase flow as the cylinder pressure drops, but I don;t think to that extent.
It could bed a fault in the reg. does it still adjust?. I'd just change the reg to the correct pressure and check the flow with a pea shooter gauge.

Cheers Rik

Yeah - I held the torch on and turned the reg down to an indicated 12lpm and it was all good for another 20 minutes (elapsed time) of welding.
It's perhaps been creeping up and I've not noticed...

 

[skotl]

Pea shooter gauge - excuse to buy something...

How do you get the welder to stop spitting wire out while you measure it? Just slack off the feed?

 

[rikrobson]

just undo the feed roller tensioner.
On the old BOC 130 I added a switch that just turned on the gas valve when i converted it to euro torch.

you can get pea shooters that fit over the end of the torch for testing and permenent ones that the TIG boys use in line with the regulator

 

[eSCHEn]

Yeah like Rik says Scott, one of the inline ones are very easy to read. Are you just using the dial on the regulator ATM?

 

[rikrobson]

Also you will bet an initial surge when the welder starts, but it should settle down within a second.

 

[skotl]

Yeah like Rik says Scott, one of the inline ones are very easy to read. Are you just using the dial on the regulator ATM?

Yep - must say that when I dialed it down yesterday it welded much better so must have been over-gassing for a while.

Also you will bet an initial surge when the welder starts, but it should settle down within a second.

That wasn't happening yesterday - it made a plink noise as the reg shot up and then stayed at 30 when I pulled the trigger.

Operator error - should check the dial each time

 

[rikrobson]

There is always a wee surge at the start of the flow as the pressure is released. you'll not notice it unless you hace a flow meter on it. The Reg won't show it. its to do with relative pressure and flows. The gas left in the line is unrestricted and all flows out as its under pressure. Once the initial gas has gone the regulated gas filling the space inthe line from the regulator flows at the set rate.

 

[backpurge]

It is always a good idea when you have finished welding to turn the cylinder off, pull the trigger to depressurise the sysrem and then wind the PA screw on the regulator fully out to close it. If you leave the regulator open all the time there is a danger that when you next open the cylinder the full cylinder pressure hitting the open regulator will damage the internals

 

[dannyp]

i never depressurise the system or back the regs off just turn the bottel off. i use an inline peashooter, i used to tweek the reg dwn as the cly pressure droped and flow increased bu now use 2 stage regulator so none of that, saves a lot of gas as well

 

[Jim Davey]

It doesn't do regs any good to open the bottle with the reg still set, nor does it do the spring or diaphragm any good to leave the system pressurised when not in use. Regs fail faster if you don't shut of the bottle, depressurise and back off the adjuster knob. Ignore the procedure at your own expense but the advice works.

 

[Robotstar5]

I suppose hobby users think of the cost when they hear the gas hissing out as they de-pressurise?

 

[Jim Davey]

I suppose hobby users think of the cost when they hear the gas hissing out as they de-pressurise?

I'd say 2 seconds worth of gas costs less than premature reg failure.

 

[Robotstar5]

I'd say 2 seconds worth of gas costs less than premature reg failure.

"5 year shelf life, pah!,this hobby reg has been handed down through generations and never let me down"

 

[Jim Davey]

5 year life is a because the elf and safety brigade have to draw the line somewhere. To be fair, I wouldn't want to have to put my name to a reg, and stand by it in terms of public liability and guarantee safe operation for 10 years, would you? Seeing how most regs are treated in the average shop I would go so far as to say 5 years is optimistic.

 

[Richard.]

I too religiously empty the system of pressure. Those diaphragms like to be flexed to stop them perishing.
Although it pains me to do it I also chuck out my regs after the date is up. Criminal I here you say!! Well the best that can happen if it fails is it dumps the whole bottle contents out. The type I buy pay for them selves quickly so it's a worthy sacrifice.

 

[Jim Davey]

I too religiously empty the system of pressure. Those diaphragms like to be flexed to stop them perishing.
Although it pains me to do it I also chuck out my regs after the date is up. Criminal I here you say!! Well the best that can happen if it fails is it dumps the whole bottle contents out. The type I buy pay for them selves quickly so it's a worthy sacrifice.

I'm happy that a sound reg will fail safe, the blow off valve if un-tampered with will do its job and vent safely without the body exploding if there is a failure. Happy enough that I would use out of date inert gas regs for my own personal use, at home say. But I don't think I'd take the same chance on oxy/fuel kit.

 

[Richard.]

Yes it's not going to blow to bits and given the love and care they get from me they will undoubtedly last much longer but I don't want it to dump the contents of my cylinder out. Mine are actually 6 years and I'm happy to replace them after that. It buys itself back so many times over in the low figures I can run it at so its not a problem. I'm on my second Elga now!! Love em!!

 

[backpurge]

If a reg fails and dumps the full cylinder contents into a confined space, your shed for example, you have just filled it with a non life sustaining gas that you cannot see, smell or taste and remember cylinders hold a lot of gas.

As a guide, if a 230 bar cylinder empties itself the leaked gas will fill a space equivalent to 230 gas cylinders, argon based gases will fill any space from the floor upwards. You only need to reduce the oxygen content in the atmosphere by around 6% and it will start to have a detrimental effect on you.