Air Tools

[cwmcobra]

I'd like to tap into the experience of this group in the use of air tools and their requirements.

I'm in the process of installing a compressed air system for my shop before getting serious about working on my '65.  I've purchased a 2-stage Ingersoll Rand compressor and will be plumbing the distribution lines in 3/4" pipe for mains and 1/2" for application legs.  The compressor pressure switch is set to go on at 145 PSI and off at 175 PSI.  I plan to put a water filter and regulator at the ouput from the compressor and secondary filter/regulators at the two application legs.  I've never used air tools before and would appreicate help with the following questions:

1.  What pressure do most tools, including blast cabinets, normally work best at?  Most are rated at 90 PSI; is this the typical pressure used?

2.  With 175 PSI max. coming from the compressor, what maximum range is needed for the primary regulator?  Most of the 3/4" NPT regulators adjust up to 125 PSI, a few up to 150 PSI.  Is there any need or benefit to upping the max. range to 150 PSI?

3.  The secondary regulators will be 1/2" NPT size and I'm planning to use units with 125 PSI max. adjusting range.  This is obviously related to question #1.  I presume no tools required more than 125 PSI, am I correct?

With your help on this, I hope to have the system functional soon.

Cheers!

Chuck

[Brian]

I would leave out the primary regulator--it is not necessary and you will have too much loss through it before it even gets to the piping.
    I have an IR 7.5 hp 2 stage industrial compressor.  24.5 cfm @175 psi.  I put it in my shed behind the house and plumbed the air underground to the house.  I used 3/4" galvanized screw pipe everywhere until it went underground, then it transitions to a single piece of 3/4" soft copper tube.  I have multiple air outlets at different places in the shop and one in the shed near the compressor. It steps down to 1/2" right before each of the Milton 1/2" regulators with water separators at each place I need air. 
  Make sure  you buy pipe dope with TFE in it to seal the 175 psi pressure in the piping.   Also, don't buy the IR filter/regulators--they are junk compared to the Milton ones.  I ordered the Milton's I have from the Northern Tool catalog.  They don't keep them in the store. 
  I have a Blast-it-all industrial bead blaster and the instructions with it say to run it at 80 psi (there is a regulator on the front it it I keep set at 80).  I keep 100 psi on the hose reels for running my air tools, and I can turn that down to 20 for using my paint gun.
  If your compressor doesn't have the automatic tank drain on it, buy the kit and put it on there--well worth it. 
  I also wire a set of 3-way switches with a light on them in series with the pressure switch on the compressor.  One switch is on the wall in the shed next to it, and the other is in my garage so I can turn it on/off from either location.  Also keeps me from having to go down to the shed to turn it on when I am working in the garage.
  By the way, I actually worked for IR until 2007 when they sold our division to Doosan.  IR no longer makes portable Diesel powered compressors--we make them here at Doosan now. 

[cwmcobra]

Brian,

This is exactly the kind of knowledge I was looking for.  Thanks a million.  You don't know how timely this is.  I was just about to buy two IR ARO 1/2" filter regulators on ebay for my application lines.  Sounds like I need to look elsewhere.  

My compressor is a 5 HP 2-stage rated at 15.6 CFM @ 175 PSI.  It will be installed in my shop with about 100 feet of line in each direction from the compressor.

The reason I planned a primary regulator is because the secondary regulators that I plan to put on the application lines (1/2") are rated for 150 PSI max. input pressure.  With up to 175 PSI coming from the compressor, I thought I should step it down before it gets to the applications.  Is that not a valid concern?  Or do I need to use regulators with max. pressure ratings above 175?  

What about a water filter/separator immediately after the compressor tank output?  Not necessary?  Too much water vapor in the line that close to the compressor?  I'll have a drip leg on the line from the compressor to the main header.  If I use a filter, should it be installed before the drip leg or after, or doesn't it matter.  I'll also have drip legs on the ends of the main lines where they tee into the application lines, just before a filter & regulator on each.  For these application filters, I'm planning the standard 40 micron for use with all my tools.  I'm not currently planning on painting and if I do get into that, I can add finer filters later.  Does this sound appropriate?

Thanks a bunch!

Chuck

[Brian]

A drip leg is mainly for gas lines at very low pressures.  Won't accomplish anything with a high flow/high pressure system like this.  It never hurts to have another filter/water separator immediately after the compressor. 
  The Milton regulators I used say the same thing on them about being rated for 150 psi, but the three on my system have been on there since 2005 when I installed it all and nothing has ever failed and I have had zero problems with them.  Just have to drain the water separator on them periodically.  The regulators are made to where they won't let you crank the output pressure up to but about 120 psi max.  I have had them there a couple of time trying to get a large, rusty nut off of something on a truck with an air impact wrench. 
  Another hint--put a ball valve immediately before each of your regulators.  That way you can turn it off easily, let the air out of your hose, and drain the water separator without having to turn it off back at the tank and drain the pressure from all your piping just to drain the water separator. 
  The only thing I would do different in my system at this point is I wish I had used the Milton high-flow quick connects that are out now.  I don't remember the letter designation for them, but you can get them at Northern Tool also.  I have the M-style like I have used for years on other systems, but they are only about 1/4" inside diameter and are a big restriction in my system.  It hurts me when I try to use my 3/4" drive impact. 
  Also, I highly recommend you go by a hydraulic shop and have them make you up a length of high pressure 3/4" hose with crimped, swivel pipe thread ends on it to connect between the compressor and the piping.  Alot of vibration in that compressor and you don't want that going into the piping like it will if you hard pipe straight to the compressor. 
  I also found some rubber vibration isolator mounts that were used under a diesel engine in a generator and mounted them between the compressor feet and a wood frame I made.  Makes it quieter, keeps the vibration out of the floor, and keeps it from wanting to walk on the floor when it is running. 

[Brian]

Here is the regulator I used.  This is from the northern tool website.  They aren't cheap, but well worth it in my opinion.  I had some made in china cheap ones on the system at my old house, and you can't imagine the aggrevation of one failing and leaking right in the middle of a big job.  
  The automatic drain on the bowl only works when you shut off all the air pressure to it.   A spring in the bowl pops the drain open when the pressure goes low enough for it to pop up. 


Milton Air Filter Regulator with Metal Bowl ? 1/2in. NPT Inlet, Model# 1108

Factory-assembled 1/2in. NPT FR duo
Filter, 0-160 PSI gauge with metal bowl, 2-125 PSI regulator
Automatic overnight drain; U.S.A.

[cwmcobra]

Thanks again Brian.  I've ordered a high flow filter/separator to install at the compressor outlet and will not use a regulator there.  I've found a couple of filter/regulator combos that are rated at 250 PSI input pressure that I will use for the applications.  I'm only looking at Milton, Parker Watts, Numatics and Norgren.  By the way, the specs on the Milton combo you referred me to show 250 PSI max. input pressure.  No wonder you've not had a problem with them!!  That's good news.

I will definitely be installing a flex line between the compressor and the hard lines and isolation pads under the compressor.  I'm interested in your comments on the drip legs, since most all references online nearly mandate the use of these.  I understand your comment about the high pressure in the lines rendering the drip legs ineffective.  I'm not using steel pipe, so I'm not sure that the pipe will cool as much as metal does as it gets farther away from the compressor, in theory making the drip legs functional to collect the condensate.  I'll probably install them and then determine how much water is drained from each in operation to confirm or deny their effectiveness. 

Now that I'm confident I have the right components in the system, what air tools do you recommend?  Which are absolutely required and which are highly recommended? 

Chuck

[Brian]

My experience has been that the drip leg doesn't do anything for you in a high pressure air system, but it definitely won't hurt anything to put it in there.  The key thing is the filter/water separator--that is what does the work.   We build Diesel powered compressors here up to 700hp,1500 CFM and 500 psi as well as separate dryer systems, and none of our compressors or dryers have drip legs on them. 
  Does the compressor you bought have an aftercooler on it?  If so, that will cool the air and condense the moisture out for your water separator to catch.  Mine has the aftercooler option and it helps alot.  Of course mine also cools alot in the 60' run under ground to my garage!   
  You need a strong 1/2" air impact, a D/A sander, a 1/4" die grinder, and one of the die grinders with the guard and abrasive cut off wheel on the end.  Those are the essentials.  An additional item would be an air chissel, but you will only use that occasionally.  I like the IR die grinders, but I recommend a CP (Chicago Pneumatic) impact wrench.  I have an IR D/A sander, but there are alot better ones out there.  The IR tools of today aren't what they were 15 years ago--they have cheapened them up alot and many are made off-shore now.  I have been pretty impressed with the CP tools I have used.   Don't get CP mixed up with the cheap Central Pneumatic that is sold at Harbor Freight tools--don't even bother looking at them. 

[cwmcobra]

No aftercooler on my system, so the filter/separators and drip legs will have to carry the load on water removal.  The first application legs will be located about 40 ft. from the compressor, so that should do some cooling of the air to them.  Each 3/4" main runs into a deadend drip leg with the 1/2" application legs teed in above the main deadends.  The the application legs run horizontally across the two sides of the shop and each deadends in a drip leg.  Each quick coupler for air access will be plumbed in vertically above the horizontals.  So there should be no air path where the air doesn't flow vertically to reach the couplers with opportunity for water to run into drip legs.  I'll be using IPEX Duratec piping for the 3/4" mains and the 1/2" runs.  Its PEX tube with a layer of aluminum sandwiched in the middle to give it the pressure resistance required and it's specifically designed for compressed air distribution systems.  The fittings are pricey, but the whole system will cost no more than black pipe and will be alot easier to install and provide for easy future system design changes if desired.

Thanks for the tips on the air tools.  I'm planning on getting the air chisel at some point to use when I do the disc brake conversion and have to chisel those pesky ball joints off.  I notice you didn't include a blast cabinet in the essentials.  I'm thinking that would get alot of use in restoring a car.  I know you have one; do you really feel it's not essential?

Thanks!

Chuck

[WkillGS]

Great info guys!
Another air tool I would recommend is a 90 degree die grinder. Then pick up a 2 or 3 inch backing pad, some coated scotch-brite discs (aka Roloc), and a mix of the conventional abrasive discs. It's a great system for clean up and prep of small areas.

For larger areas, I like a 4- 1/2" electric angle grinder. More torque than an air powered grinder. Use it with abrasive discs and wheels, 1/16" metal cutting disc, and a wire wheel. It's a powerful tool.

Blast cabinets are very useful if you have the space for one. Watch local industrial auctions...you might get a good buy.
A portable pressure-pot sandblaster is almost a necessity as well.... for frames, floors, etc.
To make a truly awesome blast cabinet,  retrofit the blast cabinet with the pressure-blaster. You'll cut your blast time in half over the stock siphon-feed gun. 

[Brian]

Blast cabinet is definitely essential--I was just thinking hand tools when I answered your question.  Don't waste your money on a blast cabinet that the media stays in the bottom of and the gun siphons straight out of it.  Spend the extra $ and get one that stores the media in the bottom of the vac/reclaim system on the back.  That is the way mine is--has a 4" hose connected to the bottom of the cabinet and the vac pull all the sand into the reclaimer and it separates out the big stuff and the dust and lets the good media settle into the funnel shaped bottom, and the gun pulls from a fitting at the bottom of the funnel.  Never had it stop up and quit blowing media.  Got mine from Blast-it-all in Salisbury, NC. 

[cwmcobra]

One more question for you, Brian.  I started reading the Milton catalog and got a headache.  Probably should include beer in that activity.....  Anyway, I was looking for the high flow couplers that you wrote about.  Got familiar with Milton type, Parker type, etc. etc.  I've attached the coupler catalog to this post for reference.  Am I correct that the high flow couplers that you recommended would be Type G?  Since I will have 1/2" NPT connections to the couplers, this is one of the only types that is available in that size and also has the greatest SCFM.  Am I correct?  It seems that the larger basic size is much more important than the coupler style.

It appears that all the air tools use 1/4" NPT connection.  So I assume that G type plugs with 1/4" NPT threads would be used.  Then there is the hose.  Is 3/8" hose used universally or do you recommend stepping up to 1/2" for high flow applications?  

Sorry for all the questions, but I hate doing stuff wrong and then having to go back and redo it.  I really appreciate your advice.

Cheers!  

Chuck

[Brian]

The ones I had looked at switching to are the H style couplers--they are 3/8" basic size.  The G style will work, but they are bigger and bulkier, and with the size compressor you are using, I don't think you would see any benefit in the G over the H.   As for the hoses, I would go with 3/8" hoses.  If you shop around you can get good deals on 3/8" hoses on retractable reels (I actually got some of those at Harbor Freight and have been very satisfied with them).  A 1/2" hose is a little extreme for the size compressor we are dealing with and once again I don't think it would benefit you that much. 
  The problem with my system is even though I have 3/8" hoses everywhere, the couplers on them are the M-style, which are 1/4" basic size, so they are the restriction in the system.  It causes issues when I try to use my 3/4" drive impact and when I use my pressure pot sandblaster. 
  For the air tools with 1/4" inlet, you can get the H style couplers that have the 1/4" threaded end on them.  Larger tools like a 3/4" impact will use a 3/8" thread.
  Definitely stick with the Milton couplers as well--made in the USA and they will last alot longer before they start to leak compared to the cheap ones.  They will eventually wear out and start to leak, but in my experience it takes a couple of years in my shop.  The cheap ones made out of Chinesium will start leaking in a couple weeks. 

[cwmcobra]

Thanks Brian.  Now I can complete my bill of materials for the project!

Chuck