New compressor landed today.

[MtnBiker]

Good to know, thank you for sharing @kb58 . I typically don't leave my compressor on when I'm not in the shop but I'll be watching for that. Did you contact CAT about it? I'm curious to know what they might have said if you did.


Hey @MtnBiker nice build. I'll have to check into Hose Power. I noticed the comments you shared about not really needing the after cooler for very intermittent compressor use (my use case primarily). Unless I read that wrong. I am looking into building a dryer manifold *after* the tank but that's not about protecting the tank of course. I'm hopeful the auto drain on the tank will suffice but I'll have to watch to see.

There are some misconceptions about after-coolers. If you are only using air out of the tank after it has cooled and the pump is not turning on while you are using that cooled down air, then you don't need an after cooler. An auto drain will accomplish the same thing.

 

[diamond]

Ah I see. I was not thinking about that correctly. In my usual use case the pump should not be running often.

You've got me rethinking where I want to go with a DIY project. I still don't think this would have pushed me to spend more than twice as much to have the version of this compressor with the dryer system from CAT. That is over 2 grand more! I may eventually end up with both types but reconsidering if building a cooler between pump and tank is more the priority now.

I'd have to talk to the folks at CAT to see if they'll provide any advice on that front. With the two pumps & the electronics there is a bit more involved on this compressor vs just the usual tube from the pump to the tank.

 

[7milesup]

MtnBiker is correct. You want the after cooler between the pump and tank. I built a cooler for my compressor utilizing two home air conditioner coils (A-coils) stacked vertically. I went with the air conditioner coils because I knew that they can handle high pressure vs other options. I used copper line going from the pump to the top of the cooler. Placing a drain leg at the bottom of the cooler is key. I get a lot of water in the drain leg but virtually zero in the tank.

Regarding steel vs aluminum tanks, I would be uncomfortable with a large aluminum tank unless it had significantly thick walls. Aluminum fatigues with pressurization cycles. The Aloha Airlines incident comes to mind. Aloha Airlines Explosive Decompression

 

[MtnBiker]

Ah I see. I was not thinking about that correctly. In my usual use case the pump should not be running often.

You've got me rethinking where I want to go with a DIY project. I still don't think this would have pushed me to spend more than twice as much to have the version of this compressor with the dryer system from CAT. That is over 2 grand more! I may eventually end up with both types but reconsidering if building a cooler between pump and tank is more the priority now.

I'd have to talk to the folks at CAT to see if they'll provide any advice on that front. With the two pumps & the electronics there is a bit more involved on this compressor vs just the usual tube from the pump to the tank.

Plasma, especially long runs on a CNC, and any serious painting are two use cases that probably justify an after-cooler. The pump is on for an extended period. If it is low volume stuff just slap some filtration on there...maybe a cheap desiccant dryer. A longer run from compressor to filters, especially with something like copper tube, will allow more cooling and eliminate more condensate. Nobody dies in this scenario.

 

[Firstram]

the dryer system from CAT. That is over 2 grand more!

You can build something very nice for much less $$$

With the two pumps & the electronics there is a bit more involved on this compressor vs just the usual tube from the pump to the tank.

I'm really curious about this, is there more than one tank inlet? All you need to do is intercept the air before the tank to cool it. The electronics don't/shouldn't know where the air goes.

Not knowing where you live or your air needs, you may not really need to address the humidity problems. Hook it up and enjoy it!

 

[diamond]

You can build something very nice for much less $$$

I'm really curious about this, is there more than one tank inlet? All you need to do is intercept the air before the tank to cool it. The electronics don't/shouldn't know where the air goes.

Not knowing where you live or your air needs, you may not really need to address the humidity problems. Hook it up and enjoy it!

Ya there's two inlet ports in the top of the tank. One for each of the two pumps. Each inlet port has a solenoid valve on it with a line coming from the bleed off valve on the corresponding pump. That I suppose is to cut off the tank from the pumps when the pressure switch cuts off and the bleed off valves lets the pressure off the pumps as a way of making the next startup easier on the motors.

I think you're right, I can definitely build one a lot cheaper. The factory version with a cooler actually has two coolers, one for each pump. If I build one my idea would be to tee the two pumps into one cooler, then from the cooler via a water trap into one of the tank inlets and just plug the other inlet. I could keep the solenoid valves on the lines to the tee or just use one of the solenoid valves after the cooler and before the tank. Just a question of which is better, keeping the cooler under pressure or bleeding off the pressure from it as well as the pumps. I'm not sure if there's a meaningful difference.

I live in Arizona at 5000' elevation so it's reasonably dry here but we do get some humidity during monsoon season. My use, for now, is pretty low on air. Usually just blowing off chips, running a fog buster, etc. I am probably going to live with it a bit before I decide what to do.

 

[MtnBiker]

Ya there's two inlet ports in the top of the tank. One for each of the two pumps. Each inlet port has a solenoid valve on it with a line coming from the bleed off valve on the corresponding pump. That I suppose is to cut off the tank from the pumps when the pressure switch cuts off and the bleed off valves lets the pressure off the pumps as a way of making the next startup easier on the motors.

I think you're right, I can definitely build one a lot cheaper. The factory version with a cooler actually has two coolers, one for each pump. If I build one my idea would be to tee the two pumps into one cooler, then from the cooler via a water trap into one of the tank inlets and just plug the other inlet. I could keep the solenoid valves on the lines to the tee or just use one of the solenoid valves after the cooler and before the tank. Just a question of which is better, keeping the cooler under pressure or bleeding off the pressure from it as well as the pumps. I'm not sure if there's a meaningful difference.

I live in Arizona at 5000' elevation so it's reasonably dry here but we do get some humidity during monsoon season. My use, for now, is pretty low on air. Usually just blowing off chips, running a fog buster, etc. I am probably going to live with it a bit before I decide what to do.

Water in air lines is a problem for painting and plasma cutting. Maybe extended use of air tools if you don't have an in-line oiler. Your Fog Buster and blow gun won't care a wit. Balance the brain damage with real need.