Have I been done?

[series2]

I've just cancelled my agreement with BOC, as it was starting to get very expensive for low volume use. I have just picked up a 10l (X equivalent)cylinder of "Argon 5" from *removed for legal reasons* in Haydock, which for me will (should) work out a lot cheaper.

Also, I bought a new regulator from Weldequip (and must say excellent service & fast delivery), as my existing regulator was the type without any gauges and I thought it was time I got a new one.

I know that BOC cylinders are filled to 230 bar (~2300 litres), *removed for legal reasons* state that their cylinders are filled to 200 bar (~2000 litres), that I can live with, still works out cheaper. When I fitted the new gauge to the new cylinder it only registered 140 bar! I've tried a friends (BOC) regulator and that also reads 140 bar.

Have I been done out of 600 litres of gas?

 

[Sid]

Sounds like you have a bottle similar to mine. It's supposed to come with 137 bar, so 140 on your gauge sounds fair.

Different suppliers have different mixes, and different supplied pressures. Assuming all supply at the same pressure is your mistake I would say.

<EDIT> Missed the bit about the 200 Bar. Ignore me.. </EDIT>

 

[GrahamGKD]

Not sure if this would account for the difference between 200 and 140 but the pressure in the bottle is temperature dependant - if you contact the supplier I expect they will tell you what temperature the 200 applies at (I know Adams did when I queried something similar with them). I'm guessing your cylinder might be quite cold right now? The gas equation PV=kT applies as in this post by rtbcomp yesterday.

http://www.mig-welding.co.uk/forum/showthread.php?t=24174

Failing that I would be inclined to query it with the supplier.

Graham.

 

[series2]

I did think it may be due to the temperature as it's only 2°C in the garage, so I've brought the cylinder into the kitchen, which is at about 25°C as the Aga is nice and toastie (the cylinder is nowhere near the Aga!). I assume pressures are given at 20°C, as this is the engineering norm.

I'll give it a few hours to warm up, then check the pressure again.

My maths is a bit rusty, so whilst I understand the gas equations, I can't remeber how to apply them!

 

[shenion]

the 22 deg change will only change it by 8%. Should go to about 155 bar.

Here thay are normally filled to 2200PSI (151 bar). I have gotten one with just 1750PSI (120 bar).

 

[Pete.]

Did you call the supplier right away and query it? That's what I would have done.

 

[series2]

I have emailed them, as I've been at work all day.

After being in the kitchen since about 10am, it now registers 150 bar. I'm going to have get on and use it, but I have told them this in the email, I suppose I'll just have to see what happens. Maybe when it's empty I'll be getting my deposit back and returning to BOC and their random pricing policy! I do still have 1 nearly full Argon cylinder from BOC.

It would be a shame if they are unwilling to resolve it as they are only down the road from me, and they did seem very helpful yesterday when I went in. I was considering getting a pure argon cylinder from them as well.

 

[series2]

I've had a reply from them this morning, apparently they also stock 137 bar cylinders and I have been given one of these in error. They have offered me a full cylinder at a discounted price on refill.

I'll accept that as a good result!