Replacement argon hose with proper fitting???

[Rambozo]

I use nylon or poly 1/8" tube.
https://www.mcmaster.com/#9685T1

[aland]

I use nylon or poly 1/8" tube.
https://www.mcmaster.com/#9685T1

What type of connector do you use?

Looking on the McMaster site I don't see what would work. I think I need a 1/8" pipe and a 5/8 NPT (male). At least the plug seems to be that on the machine side. I need to measure the other end. But I couldn't find anything that was 1/8" -> 5/8" male NPT, is that such a connector that exists?

Thanks, I'm a bit slow...

Alan

[aland]

But I couldn't find anything that was 1/8" -> 5/8" male NPT

Nope, that's a 1/4 npt, I *think*.

Maybe I need this:

https://www.mcmaster.com/#50775k327/=1aync34

And/or coupled with this:

https://www.mcmaster.com/#50775k327/=1aync34

using the 1/8" nylon tube you linked to. I'll put it here for clarity in case someone else is looking for the same solution.

https://www.mcmaster.com/#9685T1

This is without the other end. Let me go check...

Alan

[aland]

Sorry, the forum will only let you edit for 30 minutes, I wanted to put it together and change the bad link on the second one in the previous message.

Suffice to say, I think what is needed is:

2 x 1/8" to 1/4 NPT https://www.mcmaster.com/#50775k327/=1aync34 (each end of 1/8" nylon line)

1 x Converter https://www.mcmaster.com/#7919a53/=1ayo3yj (machine side)

X number of feet of this line https://www.mcmaster.com/#9685T1 (on a cart you may only need a couple feet depending on tank/cart/welder)

Thanks for that famous bozo spin Rambozo, just like butchy boy used to get in the big top!

Alan

[Rambozo]

Compression fittings are kinda finicky with plastic tubing. You usually have to use a brass insert and that restricts the flow. They are very prone to leaks if tightened too little or too much. I prefer the push to connect type that seal with an O-ring. They are dead easy, can be disconnected and reconnected over and over and flat don't leak. Here is an example for 1/8" tube to 1/8" NPT. I prefer the brass ones. There are also plastic, and now there are half and half versions where the tube portion is plastic while the pipe thread is brass.
https://www.mcmaster.com/#51025k171

Here is an all brass.


And here is a half and half version.


(Still no working inline photos on the forum software? Come on people)

Some of the fittings you linked were for 1/4 OD tube.

Pipe is measured by nominal inside diameter, while tubing is measured by actual outside diameter.
The real trick is to accurately measure and identify what threads you have. There are so many variations that I would never try to guess exactly what you have without seeing it in front of me. Good calipers and a pitch gauge will usually do the job. Most US threads are 60 degree while British (China) are 55 degrees. Measure that and you narrow things down a lot. Typically you will probably convert from what you have to male or female NPT either 1/8 or 1/4, then to the tube fittings. NPT seals on the threads while CGA and a lot of other types seal with a spherical or tapered seat and not on the threads. So while some fittings might screw together just fine, they will not seal 100%. Since you are just starting out, there is no problem just using what was supplied until you are sure of what fittings you need to make it all work. I have one flowmeter that I was never able to ID what crazy fitting was on it and I ultimately took that barb fitting and brazed it to a brass bar so I could machine it to use standard fittings.

[aland]

Since you are just starting out, there is no problem just using what was supplied until you are sure of what fittings you need to make it all work.

Blasmphemy! Now you're sounding like a real bozo!

Actually that makes perfect sense, time to get some sleep and revisit this tomorrow.

I'm very pragmatic about getting my workspaces setup and comfortable. Not something I need to worry about, but seems like a cheap upgrade.

I should focus on padding beads...

Happy trails, time for me to get some sleep...

Alan

[Rambozo]

For example...

Here is a flowmeter that has 1/4" NPS input and should seal with a washer against the flat surface on the end of the threaded spud. While the output is 12mm x 1.0 with a spherical barb "sealing" against a conical seat. Except that the body is die cast zinc, and the barb is aluminum, and both are plated to sorta resemble brass. The problem is that the barb and seat have galled so there is no way they will seal completely and this is a brand new part. That can probably be lapped in to seal. The NPS threadform is also something where they played fast and loose with the specs. The angle isn't really 55 or 60 degrees, in fact it is different from one side of the thread to the other. Some portions look National while others look Whitworth. So lets say it is a mix of Imperial, British, and Metric. Only in China!

[performance]

Just loking at some of the Miller equipment. Flow meters have the same tubing as we do. So, since ITW took over smith and combined it with Miller, I doubt you are going to get much better in a stock configuration with any brand.

[aland]

The problem is that the barb and seat have galled so there is no way they will seal completely and this is a brand new part. That can probably be lapped in to seal. The NPS threadform is also something where they played fast and loose with the specs. The angle isn't really 55 or 60 degrees, in fact it is different from one side of the thread to the other. Some portions look National while others look Whitworth. So lets say it is a mix of Imperial, British, and Metric. Only in China!

Wow, that is very subtle on the barb, thanks for pointing that out.

Alan