[Smitty151]

Hi all,
I'm hobbyist and very new to TIG welding - slowly getting the hang of it. Anyway, being the curious & perceptive person that I am, it hasn't taking me long to despise that "sspshuuuuuuuu" sound every time I hit the peddle. It's not the noise, rather the wasted argon I know that is happening. Doing my research, and as I suspected this doesn't just bug me, it's greatly identified in the community as initial "gas surge" due to operational designs between the welder & regulator and is considered a great source of wasted gas.

Background
Here's how I understand the issue :
The regulator (which is probably a cheapo) that came with my welder both reduces gas pressure to a manageable 50 psi and reduces flow to adjustable CFH via a needle valve. While welding, the psi in the gas supply hose (between reg & welder) is around 3-4 psi. However, when flow stops, the entire supply line slowly equalizes with that of the regulators design as gas continues past the needle, bring the hose up to a settled 40-50 psi. Thus, next time the peddle is hit, "sspshuuuuuuuu" the in-rush 50 psi is released as most of the gas surges out on preflow. I read as much a 7 times the supply hose's volume can be wasted each cycle. Yet understand this is actually somewhat desirable for MIG setups in keeping initial splatter away from the nozzle. Still, I'm not convinced there's an equal benefit for TIG.

Anyway, I'm a stickler on waste, so I'd like to hear some advice on how this can be mitigated. I'm sure some surge is wanted to help purge any O2 that may have crept up the nozzle, but crying out loud, I calculate this surge-phenomenon alone is wasting equal as much gas as I'm using.
I do have my setup on a cart, so I have minimized the length of my supply hose already. But as far as addition steps, I see that there are "better" quality or lower-pressure regs on the market that can get the flow-pressure down to 25 psi. I also saw a hose product (the GSS) which reduces hose-flex &total hose-volume considerably. Or has anyone invented or considered configuring the needle valve AFTER the welder (output)?

As I said, I'm a beginner here and thus I'm doing tons of start/stops, which is why this is a real problem.
Looking forward to hearing so thoughts & opinions on this subject - thanks !

[Superiorwelding]

Smitty,
Here is a video to help you out. I don't have one but have heard good things about them.
http://www.youtube.com/watch?v=sxpZuzKT ... e=youtu.be
-Jonathan

[Braehill]

Smitty,
You can purchase a torch with a control valve right at the handle that will alow you to control this.

My suggestion is to get good enough to weld on someone else's dime and you'll be able to block out that sound of your money being wasted.

In a professional welding situation the purge benefit outways the monetary loss, but as a hobbiest you will never recover the cost.

If you plan on doing alot of practicing I'd suggest you rent or lease a large cylinder so you're not spending all your practice time running to get your cylinder filled. That gas savings on your car or truck will outway the Argon loss costs.

Len

[Smitty151]

Thanks for the fast responses.
I think the 1st thing I'll try is replacing my supply hose, perhaps steel braded flexible brake line, new of course. Would just need to adapt/splice correct fittings. With 40-50 psi available from the reg, I wouldn’t imagine the small hose ID would restrict flow very much, yet is enough to reduce hose volume & resistance to expand under pressure. May need to also use JB epoxy & drill a surge-limit orifice for the welder side of the hose fitting. Together this might yield me a pseudo DIY low-cost GSS hose.

[zank]

You are correct on all accounts. There are some regulators/flowmeters that run at lower PSI. I believe some of the Victors run at 25 or 30 psi.

You've already trimmed your line from your flowmeter to your machine. That's the big offender. You'll have to think about whether the cost of a new regulator/flowmeter outweighs the loss of gas. If your machine has adjustable post-flow, tune that to be as short as possible to achieve your desired results but without any extra time.

I recently hard piped my shop with 1/4" x 0.035" stainless tubing. My cylinder is about 12' from my bench, so I had to get up to change my flow and I had two long lines (one to the machine and one to my back purge manifold). I went from having 2 15' hoses to one 9' stainless tube that splits to the two flowmeters. The first time I lit up, it was amazing. When I used to kick the pedal, it was whooooooossssshhhh. Now it's a puff. But, my old setup was a lot more wasteful than what yours sounds like.


shop upgrades by Zanconato Custom Cycles, on Flickr


shop upgrades by Zanconato Custom Cycles, on Flickr

[Braehill]

In my mind the easiest cure for this would be to put the flowmeter in between the welder and the torch and then when the welder's solonoid valve opens it will still have the flowmeter to limit this surge.

Len

[Otto Nobedder]

The Harris flowmeters we use at work are adjustable for pressure (though it's not apparent). These are the "floating ball" flowmeters, not "two-stage regulators". If you peel off the little "Harris" sticker, you'll see a standard screw that can be backed off to reduce pressure. I drop mine to about 25 PSI, and still have plenty of flow.

To further reduce surge, the flowmeter can be moved from the regulator assembly to the machine's gas input connector, with the right fittings. This reduces the surge path to the small space between the flowmeter at the input connector and the gas solenoid.

Note I don't pay for my gas at work... The main reason I do this is I hate changing bottles, especially mid-weld.

Steve S

[rick9345]

just move gas solenoid to flow meter out . no expensive hose,hose connections,just a simple 2 wire connection,power and ground

[RichardH]

Anyway, I'm a stickler on waste, so I'd like to hear some advice on how this can be mitigated. I'm sure some surge is wanted to help purge any O2 that may have crept up the nozzle, but crying out loud, I calculate this surge-phenomenon alone is wasting equal as much gas as I'm using.

Hi, Smitty.

Great thread! I'm with you on the topic, and recently posted on plumbing my shop with hard line for a long run for this reason. In shops with a lot of stops and starts (e.g., schools), vastly more gas is wasted due to surge than used during welding.

What I don't understand is that the issue is fundamental - why is the flow regulator at the cylinder instead of the welder? As noted, eliminating the hose between the flow meter and the solenoid is the solution. Rigid hose would help - white poly 3/16" i.d. tubing doesn't expand much, though it'll still pressurize.

I've had an idea to put the flow meter on the back of the welder instead, but haven't found a solution yet for the odd thread used on flow meter outlets.

Cheers,
Richard

[RichardH]

I recently hard piped my shop with 1/4" x 0.035" stainless tubing. My cylinder is about 12' from my bench, so I had to get up to change my flow and I had two long lines (one to the machine and one to my back purge manifold). I went from having 2 15' hoses to one 9' stainless tube that splits to the two flowmeters. The first time I lit up, it was amazing. When I used to kick the pedal, it was whooooooossssshhhh. Now it's a puff. But, my old setup was a lot more wasteful than what yours sounds like.

Zank,

This is a fantastic post - thanks for the pictures!

I recently had a thread about doing exactly this, and the consensus was "don't bother", which didn't satisfy me. I have some questions about your setup...

Whose flow meters are you using? How did you match the odd straight thread on their outlet? Can you expand a bit on the header you're using for the purge lines? It looks like it has barb outlets?

Cheers,
Richard

[zank]

Hi Richard,
I took apart my Smith dual flow meter. That unit is basically just a T out of the regulator to the two flow meters. All of the threads were 1/4" NPT, except for the 5/8"-18 with the nipple as you noted. These adapters turned out to be perfect.
http://www.brwtechnologies.com/mobile/P ... Code=A-414
It's a Western AW-427 RH argon x 1/4 MNPT adaptor fitting. I put one on the back of the machine and exiting each flow meter. So now everything is 1/4" NPT.
I used Swagelok fittings. They are pricey but are so nice. And I used their SS-4BHT braded flex tubing from the cylinder to the wall and the wall to the machine. I tested for leaks, and everything is good and tight. I cracked the cylinder at 2500 psi at 8:00 am and closed it. Came back at 3:00 and it was still at around 2400 psi. The best part is my flow meters are within arms reach. I'm very happy with the results.

[RichardH]

Hi Richard,
I took apart my Smith dual flow meter. That unit is basically just a T out of the regulator to the two flow meters. All of the threads were 1/4" NPT, except for the 5/8"-18 with the nipple as you noted. These adapters turned out to be perfect.
http://www.brwtechnologies.com/mobile/P ... Code=A-414
It's a Western AW-427 RH argon x 1/4 MNPT adaptor fitting. I put one on the back of the machine and exiting each flow meter. So now everything is 1/4" NPT.

Fantastic, thanks! That's pretty much my plan, except my flow meters are male outlets. I imagine they have the opposite gender as well. Not cheap, though!

Any particular reason you chose SS over copper? And did you make the header?

Cheers,
Richard

[Smitty151]

Well, I did a quick search on this forum and didn't find much discussion on the topic, so decided to breach the subject, and great contributions to this thread so far! I like what many you have done. I really like the concept of putting the flow meter AFTER the welder. I'd imagine this to be just a cleaver equation of the right fittings. Perhaps I will go this route eventually, but for now ... I settle on mitigating the supply hose flaws.

[Braehill]

One safety note I might add is to never add any fittings between the cylinder and the regulator unless you are sure that it's rated for that pressure. A minimum of 3000# and as few connections as possible.

All hoses have a service life, even stainless braid hoses are only 10 years in high pressure service.

Len


Sent from my iPhone using Tapatalk

[Superiorwelding]

One safety note I might add is to never add any fittings between the cylinder and the regulator unless you are sure that it's rated for that pressure. A minimum of 3000# and as few connections as possible.

All hoses have a service life, even stainless braid hoses are only 10 years in high pressure service.

Len

I will have to second Len. Always use the appropriate fittings for all applications. I am not a hydraulic engineer, but have been watching and learning from one at work. One valuable lesson he has taught me is to use the least amount of connections as possible. This eliminates the potential leaks and less connections to fail. Our hydraulic pressures are as high as 5000 psi, so we don't want a failure for safety and the mess it would make. The same would apply for High pressure gas.
2 cents.
-Jonathan

[RichardH]

One safety note I might add is to never add any fittings between the cylinder and the regulator unless you are sure that it's rated for that pressure.

Agreed - I can't see the point in ever wanting to move the pressure regulator off the cylinder, but it doesn't mean someone won't try. In the interest of safety, let me clarify what we're scheming here...

For those who might not know the different parts involved, a typical "regulator" on a cylinder is really 2 parts, often connected by a 1/4" pipe. The first part is a pressure regulator, where the 2000psi of the cylinder is stepped down to 25-50 psi - it's the part with the tank pressure gauge. I haven't seen one where the output pressure is adjustable, but I'm sure they exist. It's this first part that you never want to move off the cylinder.

The second part is a flow regulator, which is a simple needle valve that limits the rate of flow (not pressure) being fed into the line. This is the part with the flow meter attached, and the part we're discussing moving closer to the welder. The line feeding from the pressure regulator to the flow regulator is relatively low (25-50 psi), and the same pressure as the line that feeds into the welder - so, it's more easily extended safely.

The issue with "gas surge" is similar to what you've probably experienced with a garden hose. You can set the faucet (flow regulator) to a low volume, but if you turn off the sprayer then pressure will build up in the hose and the spray nozzle will have a heavy stream when opened until that pressure is relieved. The effect is greater with flexible hose (it swells), and much more so with gases instead of water.

What we're discussing is how to move the flow regulator valve closer to the torch to eliminate the surge. A very simple solution was suggested: use a torch with a valve in it. The alternative is to move the flow meter & flow valve off the tank and closer to the welder, as Zank has done.

(Sorry for being long-winded here... This is all probably obvious to a lot of folks, but Len makes an excellent point about safety - 2000psi is not something to screw with at home.)

Cheers,
Richard

[Braehill]

On the subject of adapters for the Argon outlet, most welders have a solenoid mounted inside the welder's case and the fitting just passes through the case. These solenoids are usually tapped for either 1/4 or 1/8 NPT and a standard street elbow could be put in place of the 90* adapter to 5/8-18 that is in place now and then place that fitting on the outbound side of the flow meter if it doesn't already have one.

As Rick9345 mentioned the solenoid valve also can be mounted anywhere in the system with the use of a pair of wires to supply the coil, tapped off your existing wires. You can buy these from places like Red Hat that are very generic, just in and out to very complex with restrictors and multiple outlets. That way you can leave your existing welder's solenoid and fittings un-molested in case you ever have to move it elsewhere and use it .

Thanks Smitty, I really didn't need another project and now I'm here typing putting together a BOM for parts for my new Argon supply system in my head. One post and you've already spent a huge chunk of my children's inheritance. I was just starting to like you too.

Len

[Braehill]

Just thought of something else that should be included in this new and improved system, a desiccant filter. Ok and while we're at it why not Swagelok quick connects. Damn you Smitty, now I need a part time job.

Len

[RichardH]

You know... A quick / cheap solution here would be to add a needle valve in the line right at the back of the welder.
http://www.homedepot.com/p/Watts-1-4-in ... /202254837
You'd need to adjust it to the max CFH you'd want, and it'd limit the in-rush.

You could use it as your primary CFH adjustment, if you can read the flow meter on the cylinder while adjusting it. (In which case you'd set the flow meter on the cylinder to wide open.)

Or, you could just adjust it to your peak CFH setting and keep using the one on the cylinder as your primary. (In which case, there would still be a surge, but at the peak CFH you set the new valve to.). This is basically what that commercial solution does - their hose limits the max CFH.

I'm off to the hardware store to give this a try!

Cheers,
Richard

[RichardH]

Dang... this was a sinfully simple solution. No more gas surge - and this is a 25' line from my cylinder!

Gas Valve.jpg (16.2 KiB) Viewed 2618 times

I opened the flow regulator all the way at my cylinder and adjusted the needle valve at the welder until the flow meter showed the right CFH. A small turn at the needle valve is easily 5 CFH - tighten the valve stem nut so it won't be easily changed on accident. (Or maybe, cut the stem short and grind a screwdriver slot in the end.)

No more "woosh" - just a nice steady stream. For guys doing a lot of short welds, this should save a ton of argon!

Cheers,
Richard

[Smitty151]

A lot of great ideas on reconfigurations!

Although I think a few might be convoluting the distinction between the part of the regulator that reduces the bottle’s psi and the CFH valve which controls gas flow rate. Albeit it’s a one-piece part so yet I do understand the confusion. That said, the relocation ideas mentioned above are more likely on the CFH valve and not the reg’s reducer, thus we are only dealing with post-reg pressures of 50 psi or less.

Yet in all the suggested solutions I note a common denominator centered around two components --> welder solenoid valve & CFH valve. The core issue being the total volume physically between these two components. Minimize it, and you solve/reduce the surge issue.

I like Richard’s design being the simplest. Note, he fully opens the CFH valve at the reg making it a moot component. He then adds (aka relocates) the CFH valve just before the supply enters the welder. In other words, the CFH & solenoid are as close in proximity as possible, which minimizes the total gas volume that will undergo the repeated pressure changes, aka surge waste.

Given this rule-of-thumb, alternatively locating the CFH adjustment at the welder’s immediate output should yield the exact same benefit - no surge. It’s only when the CFH adjustment is too far from the welder that a surge system will develop. However, in the case where the CFH adj is located at the torch end (far after the solenoid), a potential flow delay be induced - a pseudo reverse-surge concept. So in either extreme, we don’t want CFH adj too far from the welder !

Thus, if the welding manufacturing community wants to solve this wasted gas issue once and for all ... they might consider one of two potential industry standard changes:
1) Design a built-in CFH valve & flow meter into the welder itself ! Maybe redesign the solenoid valve to only open slightly as to offer the CFH desired when energized open. Maybe make it electronic on the welder’s control panel, or just a mechanical knob. A regulator (reducer) would still be needed at the bottle to get the 3000 to 40-50 psi, but the CFH meter & valve would be internal to the welder. Make it a new standard.
2) Get regulator manufacturers to start adding a soleniod to the typical regulator – aka three internal components: reducer, CFH valve, solenoid cut-off valve. Then all welder mfr’s need to offer is an external remote solenoid channel (plug) out the back of the welder. The soleniod inside the welder would be removed or disabled. Upon start-up, the welder sends power to the reg via a wire (could be built into the supply hose) to flip the solenoid open.


Ok, so until one of the two scenarios gets invented, here’s what I did to mitigate my issue for the time being. Like Richard, I used poly tubing ( I had leftover R.O. supplies). But I wish I had seen his post earlier so I’d have gotten better connectors (not plastic). Anyway, here’s what I did :

---------

Used epoxy to “adapt” (cough cough) a couple of RO fittings onto the barb’ed ends of my gas fittings - not pretty, but functional:





Then using leftover RO tubing (yellow), I routed a short run since everything is on my cart
The poly tubing is rated to 120psi so we should be fine behind the 50psi regulator.






Again, we want to get the CFH adj closest to the welder, but my very short supply line is enough not to warrant an added needle valve at the welder side.

[Braehill]

Smitty,
Unlike the one you have pictured, there are a lot of flow meters that have the regulator and flow meter as two separate units, Smith being one I believe. I have a couple of each kind and my Harris is combined and one other that I don't recall who makes, but I have a couple that are separate. So I don't think the others are convoluted in their thinking, I think they might have units that are separate that's all.

I think we've come to a few different means to an end that would work with all types of regulator/flowmeteres.

Len

[RichardH]

Yet in all the suggested solutions I note a common denominator centered around two components --> welder solenoid valve & CFH valve. The core issue being the total volume physically between these two components. Minimize it, and you solve/reduce the surge issue.

Yup!

And, what Len said - my regulator is a 2-piece design, so the flow portion could be separated and moved closer to the welder. Ultimately, my idea is to mount it to the welder's gas inlet so the valve and flow meter are conveniently together. But my simple hack here gets the effect with a whole lot less effort, so it'll tide me over for a while.

Somehow, I doubt the industry is motivated to fix this issue, given how long it's existed. My guess is that it's not a big enough issue for most welder, so market forces leave it to niche products like GSS to solve it for folks who care.

Cheers,
Richard

[Arno]

Special regulators are also designed to combat waste by adding a more 'ramp up' gas delivery instead of the first big 'surge' of gas. An exmaple:

http://www.gasiq.se/econtent/244/more_i ... mator.html

Disadvantage is price of these units though.. They are not cheap.

Bye, Arno.

[Superiorwelding]

This thread has been very interesting. I decided to see what I could come up with. I think if money in not the object, or if you were buying new anyway, I would go with a pressure regulator on the bottle and a flow meter at the machine. Because of this thread I will be taking a better look at my DC600's and possibly be making some changes on them. Both machines have LF-74 wire feeders that are mounted on a portable cart for use inside tanks. They each have 25' hoses and I'm sure waste a lot of gas.

NOTE: This was only a test. I do not have hose clamps on my barb fitting and this was tore down afterward. I will reconfigure later for use one of my TIG machines.

I decided to try something at home first and thought I would share the pictures and part #'s. This has already been mentioned, I think, but all I did was move the orifice down to the back of my MM 252. I used two identical Smith Regulators to try and eliminate differences. Running 25 CFH I deffinently noticed the surge went away entirely with the orifice on the back of the machine. I also did a balloon test on the end of my gun to check how much volume actually was used. I simply held the trigger for 5 seconds multiple times to see which would fill the balloon the most. I didn't notice a huge difference in size of the balloon, but it was there. I wish I had a Shield Gas Flow Tester to see how much of a surge was actually there with the "stock" regulator.
Parts used
Western AW-409
Western AW-15A
Western 541
-Jonathan