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Gas Flow Rate


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#1 Verderad

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Posted 13 October 2018 - 11:16 PM

I seem to be smashing through gas, Ive changed all the pipe work, added some PTFE into the treads and checked all the fittings are tight.

It could be that I have the flow up to high, what rate are others using?

 

I have mine set at about 3 ltr/min, when I pull the trigger the gauge drops to less than 1 ltr/min.

I can hear the gas and dont seem to have any problesm with porous welds.

 



#2 nicklouse

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Posted 13 October 2018 - 11:17 PM

what size bottles are you using?



#3 Verderad

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Posted 14 October 2018 - 03:06 PM

Always best to supply all the info when asking for help.
I am using Hobby Weld 5 mix

Gas Pressure 137 bar / 2000 psi
Gas Capacity 1.34 cubic metres

http://www.hobbyweld.co.uk/products/

#4 sonikk4

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Posted 14 October 2018 - 03:53 PM

A rule of thumb indoors is a gentle hiss. A howling gale means far too much flow.



#5 Daz1968

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Posted 14 October 2018 - 04:55 PM

I have mine set at about 10 litres per minute with an mb15 torch, could probably get away with a bit less wouldn’t go less than about 8 though.

#6 jonjosar

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Posted 21 October 2018 - 10:04 PM

Mine is set to 12 ltrs pm using argoshield and an MB15 torch with 0.8mm wire. As one of the other posters mentioned, a gentle hiss is a good guide.



#7 Bat

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Posted 22 October 2018 - 06:13 AM

Hi,

To give you a bit more info there's 1000 liters in 1m³ 

So you should get at least 100 minutes of welding from you bottle by my maths.

Cheers  :proud:



#8 harrythehat

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Posted 23 October 2018 - 08:06 AM

Hi,

To give you a bit more info there's 1000 liters in 1m³ 

So you should get at least 100 minutes of welding from you bottle by my maths.

Cheers  :proud:

I get those throw away bottles 1KG of gas by weight, hows that work out welding time wise



#9 MacGyver

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Posted 23 October 2018 - 06:25 PM


Hi,
To give you a bit more info there's 1000 liters in 1m³
So you should get at least 100 minutes of welding from you bottle by my maths.
Cheers :proud:

I get those throw away bottles 1KG of gas by weight, hows that work out welding time wise
15 seconds... ?

#10 MacGyver

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Posted 23 October 2018 - 06:27 PM

14.8888888 minutes...

#11 harrythehat

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Posted 24 October 2018 - 07:20 AM

does not compute

would be doing a bottle per cill at that rate :ohno:



#12 elf66

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Posted 24 October 2018 - 09:12 AM

I suspect the regulator is your problem and its not providing a consistent flow. I use hobbyweld gas with a cheap Chinese regulator and find the output pressure rises with no flow and gives a burst of gas as the trigger is pulled then it settles to a stable flow. I would ignore the gauge and try welding a test seam with little or no gas and increase the flow until you achieve a  clean weld that has good penetration and no pitting. You will easily see how poor the weld is without gas as it will look like sponge cake. As Neil says, a gentle hiss of gas is all you need indoors. After all its a shielding gas that is there to prevent contamination from the airborne gasses.



#13 Bat

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Posted 25 October 2018 - 07:34 AM

Hi,

How many litree in the 1kg bottle?

Cheers  :proud:



#14 Verderad

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Posted 31 October 2018 - 12:47 AM

Elf66 I think you are right. I’ve turned down the regulator more, it builds up pressure until released then gives a steady flow.
I turned it down until welds looking bad then back up.




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