Compressed air setup

so i have been thinking about my air setup and i want to optimize the way it functions. it has been working well. the only thing i notice that may be out of the ordinary is, i seem to get a slight pressure drop (a few psi) when the plasma fires, the gauge is mounted at the plasma cutter. it only lasts for half a second or so then levels out. i know that i should have the smallest amount of connections and bottlenecks as possible but this is what i have came up with so far. the hose lengths are necessary due to the layout of my shop. just looking to see if anyone had any ideas or insight on improving my setup. the hose between the motorguard filter and the plasma is 3’ long and 3/8 size hose. If you click the pic it shows more clearly.


is that a bead cell dryer at the compressor? If so it would be better served after the refrigerated air dryer. to get rid of the pressure drop you could add a dry air take after your drying equipment to help level out your pressure.

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Your airlines from compressor to air dryer and from air dryer to motor guard filter are too small. ideal is 3/4" from compressor to dryer and to motor guard. Then from motor guard filter to plasma cutter 1 /2" airline .3/8" airline from motor guard will work if you keep it short to plasma cutter.

I have no pressure drop on mine with this setup.


No it’s just a filter regulator dryer combo. No beads.

The extra volume in the line would probably solve the issue? That’s a good idea. I want to run pex but I’m in a temporary shop. I’m also wondering if I just have too much crap in-line. Lol there’s a lot of stuff.

I am using the max airline 3/4" X100’ kit, easy to move and reconfigure.3/4" from my compressor to first inlet of filter /dryer set up, 1/2" fittings joining each filter, then 3/8" x 6’ airline right to plasma cutter.


I’ll second larger hoses and a dry air storage tank. Your biggest problem is those 3/8” hoses. Fittings are likely 1/4” and the long run of 3/8” hose creates allot of friction loss as well.

i would recommend you also add a bead cell dryer if you want to get the driest air out of your setup. Be sure to add it after your refrigerated air dyer.


All of that 3/8 air line is going to cause lots of restrictions as the fittings are probably close to 1/4. If you have to run regular air lines i woukd at least move up to 1/2.

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The pressure gauge will deflect when the air valve opens no mater what the setup.
Set the pressure when the torch is triggered , this will provide the most accurate air delivery.

Your drain on the compressor would work better on the bottom of the tank.
What is that just downstream of your SMC fiter?

I agree on air lines being to small. I have 1" main that feeds all the drops to different things in my shop.
I do run 3/8 air line to most everything but all the hose reals feed off the 1"

Thats a nice drawing by the way!

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I’m currently set up in my garage. So I’m running a very straight forward system. I live close to the gulf coast in Texas. Moisture is an issue, my air compressor was purchased through Home Depot online. It is an “industrial air” brand. Through research I learned that a bunch of these air compressors are made in the same factory in Lubbock or Fort Worth Texas (can’t remember exactly). They are made with Chinese parts and branded “made in America with foreign and domestic parts”. I got a screaming deal on it. It could of been named Husky, Eagle, US Air, etc etc… they are all the same. I bought the ingersol rand air dryer. I also purchased the air cleaner/dryer filter combo made by Campbell Hausfield. I found that on sale on Lowes website for 50% off. I bought two of those.

I don’t want to go against what others have said based on personal opinion. This is based on my own research and prior shop experiences.

You need a pre-filter that removes oil and contaminates BEFORE your air dryer. Especially if using the harbor freight air dryer. Oil and contaminants will wreck the internal plumbing of the air dryer and drastically shorten its lifespan. Beyond that their are many different ways to complete a system. I helped set up my brothers granite shop with a 100 cfm system and we were told by the compressor company engineers that since our 1,000 gallon storage tank was outside, and our air demands were easily met by our setup, a wet storage system was better suited. Our tank was before the refrigerated air dryer. We never saw a single drop of water in the air lines.

If your setup is sized properly for your on demand needs, dry storage isn’t always necessary. Again, this subject is a wormhole. There is a lot of things that are situational. I’m just sharing my personal experience.


i just decided to get a 10 gallon dry air tank that i will run between the motor guard and the plasma, i think that should give more than enough buffer to stop the momentary pressure drop. thank you all for the messages and info!

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It should hold you over or help. One thing tho most older air compressors tanks when good and dry will turn loose a bunch of rust dust. I put a cheap hf filter on the end of my tank. That is the only restrictions my plasma has.

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Just curious, but why such big airlines? I was looking at flowrates for different size airlines. I think 3/8 was somewhere around 30 cfm. Which is way more than enough for the razorweld. Also, why need 1 inch lines when the fitting sizes are 1/4 anyway, wouldn’t that choke it anyway?

what chart is that from ?

here is a basic chart

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Just like a waterline. When I was growing up our pumphouse was about 200 feet from the house. They had 1/2 inchwaterline set at 60 psi. We couldn’t take a shower. The longer and smaller your airline the more you loose

This one
Hose Flow & Sizing.pdf (554.5 KB)

If possible, add an after-cooler between the pump and tank. Will eliminate about 90% of the water that would collect in the tank and will keep the air cool (less humid) as the pump runs during a cut. Additionally, if you want to run PEX lines (I recommend it) getting the heat out of the air will ensure the PEX does not degrade.

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Well…I finally finished enough of the new shop to get my wall set up with my compressor and tanks…


  • I removed the compressor motor from my black tank…
  • built a bracket and lag bolted the bracket to the wall on 3 studs
  • built a shelf under the compressor for my refrigerated dryer
  • my tanks both are 60 gallon units are mounted to the wall in cradles I built and places garden hose on the metal to rest the tanks on…
  • I also a trial home made copper wall cooler of 1/2" copper of 5 ’ lengths…


  • the compressor runs and pushes air behind the black tank to the copper wall cooler through a check valve into the black tank
  • the copper wall cooler has a 2" drop leg and valve on each drop at the bottom
  • from the black tank it goes through the refrigerated cooler through another check valve to the beige tank.
  • something to note is I built a by-pass valve system before the refrigerated cooler so I can service and remove the unit as required without draining all my air or risk
  • from the beige tank it goes around the shop…then to my desiccant beads and through a motorguard then to the plasma…

I in stalled a PEX drain system that starts at the bottom of the copper wall cooler and picks up drain lines from each tank and the auto drain of the refrigerated dryer…all this goes around the corner and into my shop sink…

I can manually blow down my copper wall cooler and tanks when ever I need and it goes right to the sink…

not bad eh?