plasma cutting and clean air?

[Junk]

Help please.

Been trying out my new Hypertherm 380 - makes me feel like a real he-man to zip through stuff that fast. I've been trying it with a beat up compressor that barely makes it to 60 psi any more and I know it's not clean. Don't worry - haven't used it too much, cause I don't want to ruin it.

So been shopping for a few compressor to go with it. Finally got one picked out. Now the question is, how sophisticated a filter do I need to get the moisture and contaminents out?

I could go with a simple coalescing filter for about $185 or there's things like air dryers - aftercoolers - refridgerated things etc.

The plasma cutter will be the most delicate item on the air. If I paint anything, it's more likely to be rattle can than anything important . Mainly just running air tools off it and this plasma cutter.

Anyone with thoughts? Thanks.

[Hobart Expert Rock]

JUNK..............HEAD OVER TO YOUR LOCAL PAINT STORE, DUPONT, OR LOCAL AUTOMOTIVE STORE............... MOST SELL A PAINTERS MOISTURE TRAP (TOILET PAPER CANISTER TYPE)......... THIS IS THE TYPE I'VE USED FOR A NUMBER OF YEARS............. NOTHING WILL ERODE YOUR FRONT END PARTS FASTER THAN MOISTURE IN THE LINE GOING THRU THE FRONT END PARTS OF YOUR TORCH,.....
ROCK...............[email protected]

[Junk]

Thanks Rock - so bag the other stuff as not needed?

Thanks

[Hobart Expert Rock]

HI JUNK................WELL JUST REMEMBER THIS IS MY OPINION, AND LIKE ALL OPINIONS THERE ARE A CONSIDERED AMOUNT OF KNOWLEDGEABLE PEOPLE ON THIS FORMAT................. HEY LET'S SEE WHAT EVERYONE ELSE HAS TO SAY..........THIS WAS JUST WHAT WORKS FOR ME AND WHAT MY BROTHERS AND I USE........ROCK........[email protected]

[atucker]

Checkout http://www.tptools.com . They seem to have lots of good info on their site. They also have the filters that ROCK mentioned.

Allen T.

[Franz]

You can build a moisture seperator from 3 feet of 2" pipe that will solve 90% of the problem.
The last 10% is where the expense comes in. I've added some filter/seperator units to my plasma lines that remove a lot of the remaining 10% that I bought off Ebay for about 7 bucks each.
The best place to remove water from compressed air is between the compressor and receiver, where you can acheive maximum temperature change.

As to Compressors, they have become one of the biggest BULLSNOT sales areas in America since box stores found out every home handyman couldn't live without one. Horsepower ratings have been elevated beyond the laws of physics allow, and CFM ratings are for the most part blatant lies.
Before you plunk your dollars on the counter, I suggest you go to Devair's site and become educated. Their information is honest, and in the long run, buying a good compressor will save you plenty in energy costs. Compressed air is the most expensive form of energy.

https://www.devair-compressors.com/index.html

[Scott V]

What Franz said is 100% right!I have a Curtis compressor that really is a 5hp compressor.It also turns slow for quiet operation,and it doe not pump a whole lot of water to start with.The funny thing is to buy a decent compressor sometimes it pays to go to a air compressor shop.and talk to somebody that really knows what he is talking about.Lets put it this way,If you buy a welder from HD do you really think anybody there knows what end to plug in? Same goes for compressors,and water filters.

[Dave Haak]

Hey Franz,

Could you go into a little more detail on how you have constructed water separators? I'm referring to your comment about a 3-foot piece of 2-inch pipe in this post. I'm going through this same thing now with my plasma cutter. I think I have the 10% you refer to, taken care of just ahead of the plasma cutter, not at the compressor. I'd like to add something at the compressor. I've priced the toilet paper type filters. They're about $65 for the body and $6 for the cartridges. If I can't make something, I'll probably go this route.

I've spent about as much time researching filters as I did the plasma cutter! Although, it was easy to find a $200 to $300 solution.

Thanks!

Dave

[russell]

Anybody know of a way to prefilter the air going into the compressor to keep the moisture out?
and how often do you change the T.P. filter cartridge? Thanks


russell

[Dave Haak]

russell,

I think it's compressing the air that increaes the temperature change, that creates the moisture.

OK..........somebody correct me if I'm wrong. I would also like more info on the T.P. cartridge.

Dave

[Franz]

The trick to getting water out of compressed air is changing the temperature of the air as rapidly as possible. Since compressed air is HOT leaving the compressor and because HOT air can hold more moisture than cold air, you can loose most of the water in the airstream by cooling the air between the compressor and the receiver.
Like all simple things, it sounds complecated, but it isn't. The device I make is called a verticle column condensing seperator, really a fancy name for 3 feet of 2" pipe.
Incoming air enters at the midpoint, and is directed to the bottom.
As the air enters the pipe thru a 1/2" pipe, it immediately has a chance to expand, witch cools the airstream. It also makes contact with the inside of the pipe <cold surface> where the water in the airstream condenses.
The water falls down the inside of the pipe and is collected in the bottom, and the compressed air exits the colum at the top, and goes to the receiver.
You can make it as simple, or as fancy as you want to, by adding a coaxial water jacket, fins, or wrapping the colum with refridgerant evaporative lines.
A single colum will handle [email protected]#, if you need more capacity, add additional colums in paralell.
Secondary colums between the air line and the tool will further reduce moisture to the tool, but at a lower efficiency than the one between the compressor and receiver.
I'll take a picture of one and post it tomorrow.

[atucker]

You can find out about the TP filters at motorguard.com or tptools.com. On the Motorguard site it is a Model M30. I got one from TPTools and paid $75 and the filters were about what Dave said. I redid my air system after I got my plasma cutter and got a bunch of horrible cuts. I went from a Sears portable (using hoses) to a Ingersoll Rand stationary. I piped the new one using Type M copper (brazed - no solder). I was immediately amazed at how little moisture I had with the piped system versus hoses. All the "air people" tell you to use metal piping - they're right . I have the TP filter fitted to use as the last thing before the plasma cutter, now the cuts are great. I haven't had the TP filter long enough to have to change the filter. Supposedly, you can dry them in the sun and reuse them - we'll see. They do look like tan toilet paper with a plastic core - almost the same size too. There is a writeup on the tptools site about piping with some worthwhile cautuions about drip legs, and numerous other hints on keeping things dry.

Allen T.

[Henro]

I piped the new one using Type M copper (brazed - no solder).

Atucker,

Is there a reason why you point out that you brazed, rather than soldered, that copper tubing?

I would have expected soldered tubing to work fine and to be as safe [ie, unlikely to pull apart under pressure] as brazed pipe...

Would I have problems if I ran my air system using soldered copper tubing? It had not occured to me that I might NOT want to used soldered copper tubing for 100 psi air...and I always want to stay as far as possible on the safe side of what I do.

[russell]

Thanks Dave,makes sense to me..compressing the air would put more moisture into a smaller volume of air...I was just hoping that you cut put something like a tp filter on the inlet side...to avoid getting it in the tank in the first place...

I piped mine with black pipe..so maybe I am ahead of the game there...


russell

[atucker]

Henro,

All of the sources I checked stated that soldering was not sufficient, it will eventually come apart because of vibration, etc. I used Type M copper (and a little Type K) and brazing since their ratings far exceeded what I would be running with an air system. Type L copper and/or solder ratings were too close or below what was needed. Type M and Type K are commonly used in refrigeration, which has higher pressure requirements than an air system. Actually black pipe is preferred for air, but I didn't have easy access to threading equipment and I had most of the copper tubing.

Allen T.