Plasma Cutter

[sspisak]

Do all plasma cutters need gas for it to work?

[Jerry]

The hand held units do not need gas, yet they need compressed air for the metal to be cut.

[BillC]

Does it have to be air or can it be a compressed gas like nitrogen or argon or CO2 or ??? Sure would be an easy way to avoid moisture in the lines...

[BillC]

OOPS... I guess I should have waited for the Spectrum 375 manual to download before submitting the last question...

It says air or nitrogen only...

[Franz]

The first generation of plasma machines required 2 or even 3 gasses to work, and were a complete nightmare. Hydrogen was one of the gasses, and it took some getting comfortable to play with that equasion.

Moisture in the compressed air will definitely cause problems on plasma, but it isn't insurmountable. We had a lengthy discussion not long ago on solutions from moisture seperators to filters stuffed with Kotex to provide clean air.

[Fla Jim]

I recently bought a Spectrum 375 for Aluminum and stainless. Should have got one a long time ago, I'm spoiled now. I bought a Motor guard M26 filter, and installed it on the inlet to the spectrum. I also put a Norgren filter ahead of the Motor guard to get more life from the Motor Guard elements.
My shop air is a IR 6 HP with a 60 gallon verticle tank. I have a coalescing filter on the output of the tank, and a "HI-TECH" $10.00 Harbor Freight automatic drain valve on the tank. That drain valve is one of the worlds great bargains.
In West Central Florida in the Summertime. We have humidity of 90% or greater, keeping air dry can be a real challenge. I have installed several refridgerated air dryers for customers for instrument air. But they are pricey for shop air.

Jim

[river1]

harbor frieght automatic drain vale?

i don't remember seeing one of those, do you have a part number on that?

thanks jim


i found it

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46960

[Dave Haak]

Fla Jim,

Automatic? What activates the valve?

Dave

[Scott V]

BillC,with a regulator on a compressed air cyl will also work instead of a compressor.It's kind of spendy,but there is reasons for it.Lets say you have a generator that puts out 40 amps,and your plasma pulls that much,you do not have enough juice for both a electric compressor and plasma at the same time.Of course a gas powered compressor would work better,but a bottle will get the job done.Also maybe noise of a compressor could be a factor?

[Fla Jim]

Dave:
Basically its a one shot valve. Its piloted from the tubing going to the unloader valve. Every time the unloader valve pressurizes or unloads, the drain valve bleads a shot of air/water.
to install the the valve you remove the drain pet**** on the bottom of the tank. Install the new valve assy. You then cut the tubing between the check valve and the unloader valve, and install a T fitting. Run tubing down to the end of the drain pilot. A word of advice. throw away the tubing and fittings furnished with the kit, the tubing is cheap plastic. Retube with 1/4" copper. You need a 1/4" compression T, and a 1/8"NPT x 1/4" tube compression adapter, and enough 1/4" copper to run from the unloader to the drain valve. The threads on the pilot are 1/8" NPT.
It looks like Harbor Freight had good quality Chinese government exploited workers working on these valves, they work very well for ten bucks.
I hope this answers your question.

Jim

[echo8287]

Liquid drainer

I use to have a job selling industrial products(pressure reducing valves,temp regulators,steam traps, rotary pressure joints etc. We sold separators,dryers, and an item called a liquid drainers. Some were stainless steel and some were cast iron for the purpose of automatically draining liquids from air lines,steam lines etc. They were of an industrial nature(heavy duty) but as a pressure vessel most would handle 250 psi. The internal parts were SS and were easily re-buildable. I think they were around $35 for the cheaper smaller cast iron ones and $60 for the stainless steel ones.They were made by Armstrong Machine Works in Kalamazoo Michigan.

[river1]

echo, is this what you sold?

http://www.armstrong-intl.com/products/drntraps/dt.php3

later jim

[echo8287]

Liquid drainers

Yes that was one of the lines we sold. At the time I worked for my father in law in Atlanta. We sold those to all types of industry,carpet mills,textile mills, fertilizer plants, hospitals, hotels,universities etc. Did it for about 7 years. I don't know what the price would be for one today as I did that in the 70's. The prices were based on a scale depending on what type of business you were. User ,contractor,re-seller,or you bought them to use on an aftermarket piece of equipment that you manufactured.These were very easy to re-build and all the internal parts were SS. ,even in the cast iron ones. For a small shop compressor you wouldn't need but the smallest one. They usually came 1/2 or 3/4 and you could pipe them to dump outside pretty easy.Hope that helps!

[BillC]

Originally posted by Scott V
BillC,with a regulator on a compressed air cyl will also work instead of a compressor.It's kind of spendy,but there is reasons for it.Lets say you have a generator that puts out 40 amps,and your plasma pulls that much,you do not have enough juice for both a electric compressor and plasma at the same time.Of course a gas powered compressor would work better,but a bottle will get the job done.Also maybe noise of a compressor could be a factor?

Scott,
Your point about current draw is something I hadn't considered. Thanks!