- Thread starter Wayne.
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Richard.
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The murex saffire ones were always my favourite though I think you'll struggle to get them nowadays. This is what I have now on my set. http://www.google.co.uk/url?sa=t&so...uFgLgB&usg=AFQjCNHnEmsQTmuvisQnfFRbfRa2pbAwtw
Jim Davey
R H Davey Welding Supplies Ltd
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I did a demonstration for a welder the other day to highlight the drawback of a single stage regulator.
I blanked off the outlet connector, wound the pressure adjusting (PA) screw all the way to zero, then opened the bottle. (Bottle was about 2/3rds full, 2000 odd psi)
I then wound in the PA screw until the output gauge showed a pressure equivalent my 15 litres per minute. I then turned off the bottle, so the only gas in the system was what was already in the stem and the high pressure side of the reg. I then loosened off the blanking if a quarter turn so it would leak and this is the interesting bit. You can see the high pressure (bottle contents) gauge coming down but as it did there was a corresponding RISE in pressure on the output gauge. Despite setting a pressure equivalent to 15 lpm the gauge rose all the way to 25 before all the gas in the HP side was expended.
Imagine the wasted gas if your regulator doubled its output if left unadjusted as the bottle pressure got lower.
This is how a multistage reg saves you money over time by limiting the output variation from full bottle to empty by having effectively two regulators in one body, the primary to bring pressure down to a workable level, and the secondary as the adjustable flow part.
I blanked off the outlet connector, wound the pressure adjusting (PA) screw all the way to zero, then opened the bottle. (Bottle was about 2/3rds full, 2000 odd psi)
I then wound in the PA screw until the output gauge showed a pressure equivalent my 15 litres per minute. I then turned off the bottle, so the only gas in the system was what was already in the stem and the high pressure side of the reg. I then loosened off the blanking if a quarter turn so it would leak and this is the interesting bit. You can see the high pressure (bottle contents) gauge coming down but as it did there was a corresponding RISE in pressure on the output gauge. Despite setting a pressure equivalent to 15 lpm the gauge rose all the way to 25 before all the gas in the HP side was expended.
Imagine the wasted gas if your regulator doubled its output if left unadjusted as the bottle pressure got lower.
This is how a multistage reg saves you money over time by limiting the output variation from full bottle to empty by having effectively two regulators in one body, the primary to bring pressure down to a workable level, and the secondary as the adjustable flow part.
premmington
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I have had the same thing demonstrated to me before. Multistage regulators do save gas! Plus in a cold workshop, temp changes in bottles! Make for real savings as the bottle pressure drops (nearly empty bottles).
Multistage regulators and flow gauges do pay for themselves in a very short space of time.
Last edited:
Richard.
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I think that's very reasonable
Probably got this wrong but IIRC they're made by GasIQ who are either (along with Elga, Miller, Hobart, Bernard and many others) part of the ITW group or used to be?
