I am researching the compressed air system and found discussion threads on suggesting very elaborate setup (e.g. AfterCooler, water separator, refrigerator dryer, filters …). I am a newbie to all of these, and I am a little intimidated by it. Do I really need all of these? I am a hobbyist and the cost of implementing this elaborate setup is almost prohibitive. Realistically, what do I need to start cutting. I know I can cut with just a compressor without the drying system, but it sounds like it will affect my cut quality and consumable life. When I decided to get into Plasma cutting, I was assuming just getting the machine, assembling it and start cutting. But now the machine has arrived, and I am almost done assembling the water table, I started to look ahead on what else do I need. I came across the compressed air system and found many setup options. And I am a little lost. On one hand, I want to have nice quality cut and prolong tool life. On the other hand, I want to minimize the cost of implementing it (both monetary and the amount of work to set it up). Please advise.
At the very least, you need a 1 quart desiccant dryer and a particulate filter(usually a motor guard) between the desiccant filter and the plasma cutter.
In the short term, I think Harbor Freight has a two stage desiccant filter in their Merlin line that would get you started.
With the smaller desiccant filter and no other moisture removal strategy, you will be changing out the desiccant pretty often.
This is the 1 quart desiccant dryer that I use. Amazon.com: Tru-Flate 56-081 Dessicant Dryer : Industrial & Scientific
What size compressor do you have?
I agree with David. However, I would not do the HF 2 stage desiccant filter. I did that and felt it was a waste of money. I wished I had just bought the quart sized one. I regreted having bought the smaller one almost immediately. It was just too small, and I live in a dry climate. I ended up buying the one David linked to above and it has been much better.
Where you live and the time of year will factor into how much air drying you need as well. I would say get as much as you have the budget for. Like you I am a hobby user. I haven’t had the time to use it much the past year as we just built a new home and I am still finishing up on some of the odds and ends… and the yard. 
I have a couple of coalescing filters. One right off the tank and one right before the quart sized desiccant then a motorguard right before the plasma cutter. At some point I am planning to add an air to air after cooler after the compressor tank. I also have an automatic drain coalescing filter I plan to install after the aftercooler.
If you don’t have your compressor yet… don’t skimp on the compressor. Plan on getting something with at least a 12-cfm pump and a 60-gallon tank.
I partly disagree with my colleagues. I am a hobbyist with very low usage so I don’t generate as much ‘water’ as they do. My ‘drier’ is literally a long run from my compressor to the feed to my system, that run is in my crawlspace which is cooler than ambient air but not freezing. Still, with the long run and traps at the end of the run as it turns upward, all I need at my cutter is a separator/filter and a MotorGuard filter. If I had somewhat longer running jobs I would add a desiccant dryer and MAYBE a serpentine copper trap in the cooler crawlspace.
Both of these guys do bigger jobs so do need some serious drying, but a low usage hobbyist has more latitude.
@mikets Welcome to the forum!
I inherited an old compressor. I think it’s a Furnas 3-phase compressor. Trying to search it online and found this picture that looks exactly like mine.
By hobbyist, I mean I am not using the machine for production. However, I am coaching high school kids to build robots, so the machine will be busy for 4-5 months out of a year. My shop set up is that I have a central air compressor and have a distribution system to give compressed air to various machines including CNC mill and laser cutter. My existing compressor has no air-drying system. Every few months, I have to drain tons of water from the air tank. Now that I have the Crossfire Pro, I decided to set up an air-drying system not only for the Crossfire but for the other machines too. Therefore, this set up will be close to the compressor before it feeds to the distribution system. I think it may be worthwhile to look into refrigeration air-dryer. If I set it up like this: compressor→AfterCooler→WaterSeparator→Tank→RefrigeratorAirDryer→MotorGuard. Would it be enough or do I really need dessicant filter?
RefrigeratorDryer: Compressed Air Dryer - Save on this Compressed Air Dryer
There are so many choices, and I haven’t checked their NPT sizes, CFM etc. Will they work together?
If you have all of that, you can probably skip the dessicant filter. The refrigerated air dryer should be sufficient, as long as it has the capacity to match the demand.
Don’t do a pre tank aftercooler. It’s not worth it in the long run. I praised them for a while but removed it and I’m much happier with no noticeable loss of air condition.
I run a dessicant after my refrigerated dryer, it’s a good choice.
Without the pre-tank aftercooler and water separator, does it allow water to be cumulated in the tank?
By capacity, I assume you meant the CFM? If so, how do I determine the “demand”? Do I sum up all the CFM required by each of the machines that are on the air system? Or do I just get a refrigerated air dryer big enough to handle all machines? I think the Harbor Freight one spec’d at 21.6 CFM and 140 max psi. On Amazon, there are a few choices that have bigger CFM than the Harbor Freight one.
If I don’t do pre-tank aftercooler, should I still do a pre-tank water separator to drain the water before it cumulates in the tank?
I thought the reason behind the aftercooler is that the compressed air from the compressor is hot. Cooling it down will “squeeze” the water out of the compressed air and the water separator is to collect the water and drain it before it reaches the tank. Am I not understanding it correctly?
water will end up in your tank regardless, Just drain it daily. It will be just fine. It’s just not worth the setup and the strain on the compressor pump and reduced runtimes. edit increased compressor runtimes
You should either install an auto drain or get in the habit of draining your tank much more often, especially in Summer if you live anywhere that has significant humidity readings. I personally drain mine (manually) before every plasma session. I am a hobbyist and my cut runs are generally <10 minutes.
I didn’t even read the part where you drain a ton every few months. Dang. Mine is set to drain daily at 7 am. Purges for 2 seconds and it’s good. I’ve never even seen a puddle.
I read about the auto drain using timers. It looks like the timer auto drain has the longest interval of 45 to 50 minutes. I think this is too frequent. I also read about the Harbor Freight auto drain valve. I think this is better than using the timer. Comments? The downside is needing to modify the pressure switch line.
How I Installed the Harbor Freight 68244 Automatic Compressor Drain Kit on my Air Compressor
I use wifi outlet adapters.
Ditto. I can control the timing either through the switch’s scheduler or my own Home Server to control more event-driven actions. Max flexibility.
Cool. I assume TPLink smart plug? What kind of schedule did you set? Turn on the power to the timer auto drain once daily? What interval and duration did you set the timer auto drain?
I use the Feit brand with a husky auto drain I think. The husky purges as soon as it’s powered on. I have it set for like 2 seconds, every hour. But it only gets power from the plug once a day.
you could even do a mechanical one if you don’t want the people’s republic to know when you purge your tank.