[Metal Manipulator]

The temp hit 47 today and I wheeled my wire feed outside to do some welding and the flowmeter frosted up and then you can hear the gas hissing out. Anyway to remedy this or would a regulator be better?

[fuzz1580]

what gas ? if useing co is there a plastic flat spacer between the bottle and flow meter ?

[Metal Manipulator]

what gas ? if useing co is there a plastic flat spacer between the bottle and flow meter ?

Yes co2, flat piece is in place.

[Poland308]

It’s basic refrigeration. It’s the pressure drop that causes the temp drop. Warm up your tank. My bottles on my truck see mid west winters and sometimes I need to let them warm up for an hour or two before gas flow is consistent.

[Metal Manipulator]

It’s basic refrigeration. It’s the pressure drop that causes the temp drop. Warm up your tank. My bottles on my truck see mid west winters and sometimes I need to let them warm up for an hour or two before gas flow is consistent.

The tank and welder were in the garage where it was a least 65 degrees, pulled it out and started to weld right away, it froze up in less than 10 minutes. Gas was set at 10.

[Poland308]

It’s all about the pressure drop. I can frost up a tank even if it’s summer time if the flow is high enough. There is the possibility that your gas is moisture laden and that the moisture in the gas is freezing inside the regulator at the oriface plunging it up even faster.

[Franz©]

Size of tank?
Estimated liquid content in tank?
Have you soaped regulator (s) and hoses to look for leaks?
Is the pressure regulator or the flow regulator freezing?
Is the first time you used the machine, or has the machine been in use before?
Has the machine always been configured for Co2?
Did the regulator assembly sustain impact?

[snoeproe]

I've tested at the Union hall with dual shield wire using 100% co2 gas. The regulators they have there for co2 bottles have electric heaters in them that plug into 110v power. These regulators prevent freeze up which is common with 100% co2.

[noddybrian]

Co2 likes to freeze ! the cylinders I use on the occasions I use that gas are from a company that sells it for freezing water pipes - I have always used a heater & was taught a long time ago at college that was the correct way if using that gas - below is a picture of the kind I have - mine is kinda battered looking as it's many years old - you screw it to the cylinder then screw your existing regulator to it.

CO2 heater.jpg (6.22 KiB) Viewed 3096 times

[Franz©]

I've been running Co2 on steel since 1980, and have yet to freeze a Co2 regulator. I have never employed a heater to do that.

I've seen quite a few Co2 regulators frozen over that time where people used C-25 regulators and ITW HoFart regulators which also tend to turn green inside the regulator stem and body. I've also seen regulators frozen because they were beer system regulators attempting to pass more cfh of gas than they were designed to pass.
I've also seen regulators frozen up because the machine wasn't properly equipped with a flow regulating orifice.

Another, somewhat rare, situation that will cause freeze up is using a liquid feed cylinder. Not even a heated regulator is going to like that situation. It can happen easily with inexperienced people since both gas and liquid feed cylinders carry CGA 320 valves.

Heaters MAY be necessary in high flow situations, but the average garage weekend warrior is unlikely to encounter those flow rates.

[snoeproe]

http://www.harrisproductsgroup.com/en/E ... ze-Up.aspx




Sent from my iPhone using Tapatalk

[Franz©]

"Small single stage regulators are limited to low flow rates and/or low duty cycles. Larger single stage regulators may transfer more heat to vaporize the solid CO2 accumulated inside the regulator, which may handle more intermittent flow, however, under continuous duty, can still experience the freeze-up condition."

So, how often do you lay down 100+ inches of weld in a single pass?


Sent from my garage door opener because I don't have a stupid phone and advertise for the phone manufacturer.

[snoeproe]

Franz@
You really are a true cyber bully. I could just imagine what it would be like working with you on a daily basis in a shop, a complete nightmare. A true cancer indeed.
On many threads you have been involved in, you seem to be able to turn a productive and informative thread into a childish playground with your self ignorance and demeanour.
Your going to end up driving people away from this site and I'm sure the moderators will be contacting you to address this for the better of the site. Time to hang it up Franz@

[Poland308]

Franz@
You really are a true cyber bully. I could just imagine what it would be like working with you on a daily basis in a shop, a complete nightmare. A true cancer indeed.
On many threads you have been involved in, you seem to be able to turn a productive and informative thread into a childish playground with your self ignorance and demeanour.
Your going to end up driving people away from this site and I'm sure the moderators will be contacting you to address this for the better of the site. Time to hang it up Franz@

I was looking for a calm way to make the same point.

[ljdm1956]

Franz@
You really are a true cyber bully. I could just imagine what it would be like working with you on a daily basis in a shop, a complete nightmare. A true cancer indeed.
On many threads you have been involved in, you seem to be able to turn a productive and informative thread into a childish playground with your self ignorance and demeanour.
Your going to end up driving people away from this site and I'm sure the moderators will be contacting you to address this for the better of the site. Time to hang it up Franz@

I was looking for a calm way to make the same point.

Maybe trying to get banned here, too?

[noddybrian]

Back on track - I do accept you can run CO2 without a heater at limited flow rates on an intermittent basis without freezing up solid but flow tends to vary erratically as dry ice particles & liquid move around - also depends on size of cylinder vs flow & cylinder contents - a new cylinder has less space for the liquid to evaporate in so is more prone to liquid carry over than a nearly empty one - all this aside to achieve a stable flow of gas the heater is the best way as I was taught as the gas will be warm enough to be a true gas of uniform density - un-heated you tend to get particles of solid plus semi expanded gas plus some liquid vapor so on cost alone it's better to heat in my opinion . there have been a couple of guys on here that could explain this in a more informed & scientific way than me but sadly they don't seem active on the forum recently - I hope that if Franz remains a member he will read his replies before posting & make them a little less aggressive & more constructive - maybe this is just how he is - maybe he's just a dick - who knows ? either way I hope the forum keeps it's friendly helpful outlook as the founder intended.

[Franz©]

As a wise man once said; "If everybody in the room is in agreement, half the room ain't thinking.".

Liquid Co2 in a cylinder, with the exception of a liquid feed cylinder simply can and does not reach a level of the cylinder to exit as a liquid when the cylinder is in a valve up orientation unless the cylinder has been insanely overfilled. Safety valves on the fill system would prevent such overfill if the fill station operator attempted overfill. Co2 has very specific properties and they are well known. Ergo, it is silly to proffer liquid is entering the regulator UNLESS the cylinder is not properly oriented.

Internal regulator freeze can and does occur when the regulator is overworked. Comparing the regulator in any gas stream to the expansion valve in a refrigeration system is valid. Expansion valves are "sized" and adjusted in some cases to deliver gas to the evaporator from the liquid reserve in the receiver and line system.
Given there is no low pressure chamber in an expansion valve, one must consider the evaporator to be the low pressure chamber. When excess gas is passed through the valve, the evaporator floods, and often fails to remove heat from the surrounding area. Since this isn't the desired effect, the expansion valve is adjusted to lower flow.

Carrying the comparison ahead to a gas pressure regulator, the low pressure chamber of the regulator body and tube system from regulator to solenoid in a MIG welder become the evaporator, as long as the solenoid is open and passing gas.
Refrigeration by expansion of gas occurs in all of those cavitys.

Given the low pressure chamber of the regulator is the nearest point to the valve controlling the stream of flow, it is the most likely point for a thermal freeze to initiate. The same thing can and does happen with expansion valves in refrigeration systems. All considered, there is little difference between what a pressure regulator in a Co2 stream and an expansion valve in a Freon stream does.

The "Problem" was in fact first noted in the 1920s when Co2 systems replaced Ammonia systems as a safer refrigerant gas. Co2 systems worked well, delivered nearly the efficiency of Ammonia, but they were nightmares to regulate. Co2 systems went out of favor fast.

Add in Co2's property of transitioning from gas to solid, unlike other gases, and internal freeze up becomes a big problem.
Unlike a refrigeration system, under normal conditions there is no liquid Co2 at the hi side of a welding or beer tank regulator, but Co2 can and does go from gas to solid. When that happens in a welding regulator, you either have gas leaving the low side of the regulator at excess pressure, or no gas leaving the regulator until thaw occurs.

Solving the problem became a concern in the 1980s when MIG process became viable outside labs.
Since only pressure of the gas stream is regulated by the first regulator at the cylinder, flow volume regulators were added to the gas stream to control CFM leaving the pressure regulator in the hope that would both tame the discharge at the nozzle of the gun, and stop pressure regulator freeze up. It worked well on intermittent use systems.
Engineers became involved and employed their discipline. Cold = freeze, so eliminate cold by adding to energy consumption. It sort of works.

Others took the alternate path employing knowledge of refrigeration by expansion. When an expansion valve passes insufficient gas flow to the evaporator, insufficient cooling of the evaporator happens. Since the low pressure chamber of the regulator is an evaporator, increasing that volume also solves the problem without ongoing cost. Adding a low pressure cylinder to the system buffers the gas stream as well and lowers turbulence at the nozzle slightly. Move the flow regulator downstream from the L.P. accumulator, and you gain control of the gas stream.

Nothing in the above factors in the pure joy of brass corrosion in a Co2 environment. ITW Hobart did a wonderful job of demonstrating Co2 brass corrosion by the use of cheaper alloys of brass. ITW refused to rectify that situation when independent testers warned them of it. After all, the regulator was projected to be beyond warranty when the fail occurred.

The choice is do you think your way out of the problem, or do you spend your way to a simulated solution.

[noddybrian]

Thanks - that was a well thought through answer & I can't fault the logic at all - everything you say makes perfect sense so I guess to a degree I'm guilty of accepting something taught at college on faith as gospel without proof - my only nagging doubt on this is most places I've seen CO2 used ( which is'nt many over here ) used heaters - those that tried without mostly had erratic gas issues believed to be temperature related or experienced much higher gas consumption to the point it payed to use heated regs - obviously I have no idea who was setting what CFH on any given machine so it could just be operators influencing this - either way interesting debate on a little talked about subject so thanks for this latest input - there are a couple of refrigeration guys active on here so I'm interested on they're take on it though I doubt they use CO2 as a shielding gas so may not be able to comment past the theoretical.

[ljdm1956]

Reminds me of a doctor I had, really good, caring, thoughtful doctor, but his bedside manner sucked. In his case, guess he didn't have a way with words? Just sayin'

[Metal Manipulator]

Thanks for the replies, will need to sit down and read them good. I'm a new first time grandpa and haven't had much time the last couple of weeks.