Why gas lenses work...

[justmental]

I did start my post by saying people dont like different opinions.

I am only trying to open yr eyes guys.

How many people have seen tried them silly water savers for a house hold tap.

The gas lenze works on the same principles
Now how many water savers have ended up in the bin.

the gas lense does at it says saves gas and gives better coverage

i know what you mean by the gas flow i work on race cars and built a few.
its not that we want the best flow / speed from it its coverage and less gas to be used and the do there job and good at it they are as well.

 

[justmental]

I've got 200 bar to play with on the pressure side, I don't think it's an issue, I'm not trying to force as much gas through the lense as possible, because it's a none issue, all you want is a nice, evenly distributed laminar flow.....basically, comparing it to a cylinder head flow makes no sense whatsoever.
Neither does comparing it to a water saver.

hit the nail on the head there Phill.

 

[wheresmejumper]

works out about 20 euro for cup,and same for post to Ireland.
stubby is a bit cheaper.ill just wait till i need a few more things to justify post

 

[justmental]

looks like you need somebody over there to stock them to save money

 

[Piero]

Justmetal

If you have tuned a car or two you must have a grasp on flow.

The gas lenze can be seen directly as a water saver for a water tap.

I am saying there are better ways of acheaving a stable gas coverage.

Latter tonight I will post some pics of my older boc tig touch and show the way they direct the air to achive a stable controlled cas coverage.

The run of the mill collect bodys used on normal none gas lenze tig torch es direct the gas straight at the wall of the ceramic

This is what causes the gas to be turbulent

 

[justmental]

yes i know what you are saying Piero.
but for most buying a gas lense saves on filing a normal collet body.
me personally i just use the lenses i have.

 

[wheresmejumper]

i could be wrong,but i think rapid are the only seller stocking them this side of the atlantic.
its them, or weldfabulous or arczone in the states.
it is really handy for tight spots though,especially on ally as you can see when it pools and its time to move

 

[justmental]

i could be wrong,but i think rapid are the only seller stocking them this side of the atlantic.
its them, or weldfabulous or arczone in the states.
it is really handy for tight spots though,especially on ally as you can see when it pools and its time to move

yep think they are i have 2 pyrex cups 1 large and short.
and as you say great for tight spots and able to see through the cup.
the only problem i have is with the small one in needs a rubber seal at the top of the collet body to hold the small pyrex and ceramics on as they slip of to easy. looking at sorting that now.

 

[FranV8]

Piero, your opinion is valid, alas your science is not.

In terms of my understanding of flow, it featured quite heavily in parts of my degree and throughout my career I've calculated pressure drops through pipework systems and fittings, and sized/checked pumps for flow and pressure requirements.

If you can understand Reynolds number, turbulent and laminar flow, what the relevance of pressure is here (not a lot in this application) then I'd feel you had a good grasp of the subject. Instead with your empirical observations and now comparison to water savers (can't see the relevance) I think you'll have only got lucky if you've a better solution.

I'm not willy waving, because I wouldn't put my background knowledge up against the welding industry's years of development on this, it's in their interest to make technology that makes the welding process more efficient and more robust (I. E. Less chance of contamination). Experience on here also backs gas lenses as a good thing.

I'm still looking forward to seeing your solution, it could still be a good one. But it doesn't make gas lenses snake oil either.

 

[Piero]

My silance is due to trying to work. Sorry but its a nesosery evil.

With your willy waving knowage I cant understand why you cant grasp or understand what I am saying.

Pipe pressure and turbulence is very relevant
Hence my suggestions to spin the gas in a vortex type movment around the collect body.
To surgest I have stumbled apone this idea is rather insulting.

We have a massive amount of pressure at our disposable this is not the problem.

Please read this point carefully.
We are sold a gas lenze on the pretense that it will create a stable gas coverage and in doing so save on gas.

The reason they claim it saves on gas is something we can agrue latter.
What I am saying is there are better ways to get steady gas coverage with less use of gas. Simple.

If you cant make the link between a gas saver and a house hold water tap saver then I must conclud I am waisting my time on you.
This is not a personal coment on your person. But I feel it pointless to keep expaining and getting no were.

I have explained and given my reasons for anyone willing to read my points and hopefully see sence in them

I will post some pics for reference and will back out of this topic for others to have there say.

Thanks

 

[carlos420uk]

I also use the ck gas saver gas lense's and find them to be very good.

I think the standard collet bodies and cups come in to play when you have less than favorable quality metal to weld (ie dirty steel, mill scale, zinc coated etc). There is always that job that needs doing where cleaning the base metal(s) is not practical, or even possible in some cases, and you wouldn't want to go ruining gas lens screen's from those contaminants popping out at you.

For everything else I will always use a lens as I personally like to be able to stick my Tungsten out quite far for best results.

I have a mate who has been Tig welding for over 10 years, up until I gave him one he had never even seen a or heard of a gas lens - or used a foot pedal for that matter.

 

[chevy2]

Piero, you and others may differ in opinions on the best way of flowing gas, none of which i feel qualified to question, i'm sure there are better methods out there for those who wish develop a better method.

back to my original post which simply stating that gas lenses do perform better on gas coverage than standard (unmodied) collets,

if you need to for example weld an acute approx 20-30 degree angle joint on tube which i often do, thats a recipe for porosity with a regular collect without cranking the gas up to a rediculous high level, whereas with a gas lens this can be done easily with the tungsten let out up to an inch whilst keeping a sensible flow rate at around 6-7lpm,
showing that their coverage outperforms a regular collet.

 

[PhillipM]

Pipe pressure is not at all relevant, as we're not even close to the flow limits of a cup - you'd empty a bottle of gas in seconds if you were.
If you spin the gas in a vortex all you will do is draw air in from the outside and mix it as the gas spins. And you'll also find the gas will spread in a cone.

A tap saver simply reduces the pressure available to create flow, again, this has no relevence, we have more pressure available than we know what to do with, it's like claiming the water saver will work when the tap is only open enough to drip anyway.
The gauze/filter is there to act as a diffuser, something it does a fantastic job of very cheaply and effectively.


And as it's turning into a p***ing contest, there's a few of my cylinder heads are on multiple championship-winning cars
But given it's not relevent at all to the dynamics, it doesn't matter.

 

[langy]

I did start my post by saying people dont like different opinions.

I am only trying to open yr eyes guys.

How many people have seen tried them silly water savers for a house hold tap.

The gas lenze works on the same principles
Now how many water savers have ended up in the bin.

Well i guess its time to remove all my gas lenses and bin them as they are obviously no good !!! All those years i've used them have been wasted

 

[justmental]

Well i guess its time to remove all my gas lenses and bin them as they are obviously no good !!! All those years i've used them have been wasted

maybe if we take the screens out to remove the restriction they may work even better. lol

 

[wheresmejumper]

scotchbright is used a lot as a makeshift diffuser

 

[backpurge]

I personally get a very small needle file and file the exit holes in the collets so as to create a swerling affect. Much like a vortex.

Creating a vortex is the last thing you want to do

 

[citizen kane]

I wonder if NASA know how to produce laminar flow?

http://www.grc.nasa.gov/WWW/k-12/airplane/tunpart.html

 

[Seano]

If Piero's theory is to be believed within the welding community a lot of companies have wasted a lot of money developing gas lenses and cost us a lot of money buying them...... I think not. I understand what you are saying regarding swirl and flow, within an engine that is what you need to get a thorough mix of fuel and air, but in tig welding no mix of anything is required in fact a mix is the last thing we need, what we need is pure Argon with no air present to give complete contamination free coverage of the weld joint, in the first illustration you will see a large swirling mass of gas as it spreads away from the weld, hence one of the reasons for such close proximity between cup and tungsten to the weld, in the second illustration you see a pure column of gas which is produced by the mesh structuring the higeldy pigeldy swirl of gas post mesh, in short we are looking for coverage not flow.

 

[philxx1975]

I hate to be the spanner in the works but I wouldn't be to sold on a gas lanze.

Shock horror! !!!!

Fearing not being popular. As most don't actually like different opinions but I have been involved in flowing of cylinder heads and the like for many years.
Its not my day job but neither the les I do understand the moment of gas

Normal ceramics collets etc
I personally get a very small needle file and file the exit holes in the collets so as to create a swerling affect. Much like a vortex.
The ceramics need to be bulb like at the top end were they meet the torch.

The gas is exiting sideways and hits the ceramic face on creating a confusion and a possible bottle neck near the exit portion of the ceramic.

So In practical turms the gas lenze could be seen as better.
The gas is exiting stright down the ceramic.
The gauze is restriting the flow and as such they have widend the serfice earea to alow for no losses.
But in doing so. They have slowed down the flow rate.
In the fat part of the ceramic of a gas lenze. It holding twice as much gas.
They will be a pressure drop
Not a good thing.

Theres a lot more to it then that but I have not given it to much thought
Have a look at what fronius use as a ceramic etc

it looks from the photos like what is being created is laminar flow

just an observation as welding isnt my job but computational fluid dynamics is that an engine needs to mix fuel and air and then the ported head if you will in its simplest form to evactuate that air cleanly for the next cycle to begin

In welding it appears that its purpose is more akin to an operating theatre whereby the gas shroud doesn't want to drag,or at least limit the inflow of contaminant gases ,if you ever get the oportunity to look up?? before they put you under the knife you will notice filters behind a very fine gauze screen

This provides perfect laminar flow downwards and prevents dirty air being drawn into what is effectively a sterile zone, these are augmented by coanda effect skirts to provide a curtain of air around the perimeter of the downflow unit

the mean rule is 0.5m a second for good laminar flow so im assuming the gauze is providing something similar,