backpurging question

1. A second tank of argon for backpurging.

2. Split the line after the flowgauge, but it will skew your flowgauge reading for the welding shield.

1. Use a tank Y-connector so you can hook up 2 flow gauges to the same tank.

1. Use a dual-port flowguage with 2 flowguages tubes running from one regulator diaphram.

I use solution 1 at school where we have extra tanks.

I use solution 2 when on location welding stainless steel at breweries.

In y shop I started with solution 2 then went to solution 3 and ended at solution 4.

You can buy a dual-port flowgauge, or just make your own by adding a second ball-and-tube to a stnadrd flowgauge. I like Smith flow gauges. Just unscrew the single ball and tube and add a T-connector to add the second tube. You can buy a tube from them or beg one from a repair shop. I found an extra one from a broken regulator at school.

A flood light would help, but if you have a real Speedglas thne set your sensitivity knob.

Set the sensitivity so it won't quite react when staring up at the ceiling lights.

Hi

I used the 3rd method Ernie described. Regulator off bottle, then long hose to workplace, then Y-fork and

- one flowmeter for supply to TIG welding machine

- one flowmeter with stop valve (big handle) to backpurge

The whole arrangement of Y-fork, flowmeters and on/off valve on the backpurge line I clamped to the edge of the workbench, so could adjust flows and turn on/off the backpurge from where I was welding.

Then can turn backpurge on and off, so can use decent backpurge flow when welding without wasting Argon otherwise. And both flows can be adjusted from where you are welding.

Had a little higher pressure out of the regulator than absolute minimum needed to push desired Ar flow through both flowmeters when wide open, so that opening and closing one had little effect on the other.

Many thanks to Ernie and everyone advising me when I was setting-up.

Richard Smith

Ernie Leimkuhler wrote:

backpurging. I

flowgauge

breweries.

Hi Richard, I am trying to get some prices on a dual delivery flow meter but I reckon they are quite dear and I might go for (door) number 3 too. I already have one regulator and for door number 3, the cost would less. I already found the price of a standard single delivery flow meter is around CDN$125.00. The Y-fork fittings would likely run another $25 bucks but I have not yet asked for prices on that stuff yet.

But, I sure like the elegance of having a dual delivery meter. Beauty knows no pain. (We'll see.)

Your comments are helpful about having adjustment at the welding table. I don't think I'll need or even want that in my situation. However, I was wondering about some sort of shutoff valve at the weldment end of the purging line. I had rejected this idea thinking that once I got the weldment all ready to go--metal positioned and the purge line in place in the dam--I could then go to the flow gauge and turn it on. Then in the couple of steps it takes to get back to the welding table, the dam would be purged and I could just start welding. Once the weld was completed, the walk back to shut the gauge off would give me post-weld protection. In writing this, I just realised that I had not thought about all the stop and go that can occur in some welds. Humm... Are there reasonable savings to be had from having a shut-off at the delivery end of the purge line? I guess you think it is worth while, eh?

Ah, I like the smell of argon in the morning.

Ciao, David

The prices you are seeing are higher than I am paying in Britain, where usually prices twice as high as in US

If recall right, Y-fork would be "a few bucks" (for nice piece of brass), ea. flowmeter would be about equiv. $25US *in the UK*.

Welding of a jobbing or amateur kind tends to be stop/start, as you comment. So better have on/off valve near job - and marked so you can easily see whether it is on or off. Is pain to have to go get new bottle of Ar because you left the purge line on for hours. Bit of practicality.

Don't need dual flowmeters to have on/off tap at workpiece, but accurately judging purge flow always good - always worth it (?).

Best wishes welding.

RS

PS - > Hi Richard,

already have

CDN$125.00.

Beauty knows

savings to

setting-up.

suggested

adding a

autodark