Shop air

[metalspinner]

I picked this air compressor up last year from a local paint and body shop. It's a 7 1/2 hp, 120 gallon tank with a two stage pump.  They were upgrading to screw compressors. 



 
Finally, today, I got it up and running. 
The guy that used to maintain this unit for the paint and body shop came out to give it a once over for me. 
I still need to plumb it in and will get to that in the next couple weeks. I'm thinking about using Rapidair piping system. Anyone here use this for their shop?
I need clean, clean air because I also spray auto paints and clears. 
Part of the package I bought was a refrigerated dryer. The guy that came to the shop, he and his dad actually designed and manufactured these dryers them sold the company. He was very happy to reunite with the dryer and was eager to share his passion for air. 😉
Here's the dryer when it was hooked up at the body shop. 


 

[Walnut Beast]

Nice setup. Dryer further away from compressor. Copper pipe with a tee fitting pointed up then make a riser coming back down with a connection for your air hose and various locations a few tees down with a shut off to open and let moisture out. I had a looped system this way and a moisture separator and never had moisture problems painting or sandblasting in a cabinet inside and sandblasting outside with a pressure sandblaster 

[21incher]

I used the 3/4inch size that comes in a roll out in my machine and auto shops. It works good but looks terrible.  It is impossible to get perfectly straight rolled out piping. Doesn't  really  bother me because  it was the cheapest option and works good for my needs.  Now I see they sell rigid systems that would  look better.  I use a toilet paper type filter  as the final filter  for my plasma cutter and painting because  they will remove the synthetic  oil that seems to always find a way into  compressed air systems when using it in the pump for longer life. Most std separators will not.  I think rapid air piping is approved by most building  codes.

[Walnut Beast]

This is a 10hp pressure lube air compressor and ran copper piping with a pipe going down with shut off to drain moisture coming out of compressor plus automatic on the bottom of the 80 gallon tank. Hard copper to compressor because this unit has virtually no vibration. No moisture problems with copper

 

[sawguy21]

Nice setup! You definitely want the oil separator with your usage. We ran a blast cabinet with soda so the air had to be dry, the lines were run high on the wall and each drop had a ball valve below the hose bib to drain any condensation. I question a toilet paper filter, you don't want the fibers in your guns.

[Southside]

A buddy of mine bought a highway painting truck for the cab and frame.  Asked me if I would be interested in the compressor that is run via a hydraulic pump powered off a 4BT Cummins.  Need to go take a look at that.  Was thinking along the lines of a 1,000 gallon propane tank for storage and a quick connect to keep the unit portable when necessary.  I am jealous of the setups you both have.  My "shop" compressor has been found wanting on many occasions.  

[Larry]

I bought this low hour Champion at auction about 10 years ago.



It ran a Walmart tire shop and came with a 15 hp motor.  Couldn't start it with my RPC reliably, so I swapped it for a 10 hp single phase.  One of my better buys.  I thought about getting a dryer but with the big tank and low usage I don't have any problem with water.  I use it with my plasma, sandblaster, widebelt, and spray lots of lacquer.  I also use it with my Dynabrade ROS, the Festool got sold!

I won't show my plumbing......not quite professional :D :D.

Good luck with your machine, it looks sweet.

Edit, I should add that I do use a water separator and toilet paper filter on the plasma.  I found spraying lacquer the air is dry enough I don't need the filter.

[21incher]

Nice setup! You definitely want the oil separator with your usage. We ran a blast cabinet with soda so the air had to be dry, the lines were run high on the wall and each drop had a ball valve below the hose bib to drain any condensation. I question a toilet paper filter, you don't want the fibers in your guns.

Look up motor guard m60 it's a sub micron filter.  They call them toilet paper filters because the cartridge looks like a roll of toilet paper.  Ingersoll synthetic oil goes through most standard filters.

[doc henderson]

I have an IR 7.5 hp 80 gallon tank in the basement under the wood shop. 34 x 50.  It starts out 1.25 inch black iron pipe and transitions down to 3/4 the goes in a loop around the basement.  there are two drops to drain any condensate.  the air to the shop goes up inside the wall and out.  so the flow can come from both directions.  the pipe added 11 gallons of storage.  I have another 80 gallon tank. and a spare 60 gallon tank.  if you mount the intake remote in the attic or outside, it will reduce the noise.  Mine in the basement is barely audible in the shop.
I made a base and added 4 inch casters.  I also bought a 2 foot section of flex hose so the compressor does not vibrate the actual pipe.

[Erik A]

A word of caution... I worked at an auto shop that had run pvc for the air, it was up high above the lights, not that that is any better, but a kid jumped up on a bench to drive a nail with a hammer and hit the pipe! It blew 2 to 3 ft pieces out of a 50 ft run all over the shop!

[doc henderson]

yes! do not use pvc.  it degrades over time and will explode after you have grown to trust it into shards.  I made a potatoe/confetti gun out of 3 inch pvc in the shape of an H.  used it in a cub scout parade.  it worked fine.  we won first place for a Christmas theme and shot "snow in the air twice a block.  5 years later pulled it out to test it and at 30 pound I heard a creaking sound and told my son to get behind a pallet.  i thought it was warped and rocking in the sand.  I touched it with my foot.  It exploded with enough force to dent metal and break trim on the garage door.  5 different neighbors came to see if we were ok.  we found pieces of it 150 feet away.  I had a tiny dot of blood on my sternum.  eyes got lucky.  thank got it was not in the back of my truck at that July 4th parade.  I could still be in prison if they thought I brought a bomb.  I got a bead seater and used it for the confetti gun tank.

[sawguy21]

@doc henderson  brought up a good point. We had a larger unit in an upstairs store room to free up floor space and eliminate the noise but it got so hot in the summer the pump paint started to discolour. The maintenance man ran an intake pipe outside to a Donaldson filter, it made all the difference. The pump ran cooler, quieter, cycle times were shorter and there was far less condensation. The intake was screened to keep birds and insects out.

[doc henderson]

you could use pvc for the intake, but not the pressure.

[Crusarius]

if you want straight runs look up maxline pipe straightener. 

[Walnut Beast]

The reason why copper is so good for piping is it dissipates heat the best and that's what you want to get the moisture out. Downside is it's expensive and a little labor involved

[firefighter ontheside]

I was all impressed with my new to me 33 gallon compressor for my shop, but now I have envy.

[Tom King]

What refrigerant does your dryer run?   Mine is old enough to use R12 (or R22-haven't looked at it in years), and I'm undecided what to do whenever it needs work.  I put the rebuild kit on it (new automatic drain, and bits), which doesn't have anything to do with the refrigerant system, but have never messed with it, and fortunately, it still works like a new one.

[blackfoot griz]

 





My favorite tool. Best $450 I've ever spent. Right now it's a scabbed-together setup in my basement.

[Al_Smith]

At my shop I have a 5 HP two stage dumping into two 60 gallon tanks with a drier and oil/water  filter .It's connected to the main line using hydraulic hose just because I have an abundance of same .Most of the shop is just 1/2" black iron pipe with ball valves below the drops .On at 140 PSI and off at 160 .It's just a system I cobbled together from junk I already had . I also  have I think a "speed air " or what ever Grainger sells 10 HP sitting on top of a 120 gallon tank that is a works in progress so to speak .Again just stuff I amassed from holding my hand up at an auction ,several sales .

I might add that double tank deal I usually only dump into one tank .However with both tanks on the line it will raise my car lift at least a half dozen times before the compressor fires up .That lift has a 13.5 " air/over hydraulics cylinder and will lift a pick up truck on 60 PSI . 

[doc henderson]

on the topic of additional tank storage, I am a fan.  you have to be careful that your compressor has a duty cycle that can support the volume (especially if you tend to go all out on these projects).  I think if you had an oiless with a plastic piston and reed valves, you could burn the thing up.  I am not sure if any compressor is intended to have 100% duty cycle.  all the moisture has been in the tank attached to the compressor.  the second is 10 feet down the line, and never has water to drain.

[Al_Smith]

I have the 5 HP set up to run all the time if I want .Much to my surprise I over looked that and before I noticed it it was upwards of 200 PSI before I switched it back  to pressure switch control .My word would that auto hoist move fast with that much pressure on it .Impact wrench had a lot of extra grunt too .
The little compressor in my home garage is a 3HP Craftsman I've had for 40 years .On at 90 and off at 120 PSI I think .At those pressures the impact tools don't have nearly the power as at my shop which is 22 miles from my home .Not real handy .

[sawguy21]

  Be careful, if something gives at that pressure you won't be able to move fast enough!

[Al_Smith]

That 200 PSI was just me not paying attention .

[Larry]

I am not sure if any compressor is intended to have 100% duty cycle.

My Champion as some others have a 100% duty cycle.  I doubt they are intended to be run this way.

My compressor sits outside under the shop shed.  When I wired it up I installed a relay next to it with a remote toggle switch inside to turn it off and on.  While doing that, I also put a light next to the switch by the door so I know when its on.  The light reminds me to turn the compressor off when I leave the shop.

[doc henderson]

Mine is a 100% duty cycle too.  but if you had a leak like a broken pipe and it ran for hours or days, not good.  also at the highest pressures, it works hard and puts out less volume.  just like a heart, it only moves volume when the piston compression exceeds the tank (systemic diastolic)  pressure.  be sure and have a pop off, that should be at the rated pressure for the tank.  If you push (exceed) the limits of the system, do not be fooled if it works day one.  it may fail after 20 years of "abuse" when you least expect it, like when grand kids are over.  I ran a pex line underground from my shop air to my pool house, so I could blow lines out.  I was at work and a filter cup in the pool area blew off.  the neighbor heard it and came to the door to tell my wife.  I was able to tell them where the shut of was .  but when I looked at the system the paint was bubbled up on the compressor cylinder.  too save space I thought about puttin a spare 80 gallon tank outside, and even considered putting it underground outside.  the cool would prob. condense moisture/dry air, and require a drain at the bottom with a valve above ground.  It is fun to have spare time to think of ways to maximize systems like compressed air.  final thought, little leaks add up.  wear and tear on equipment, and electricity costs.  I currently have two spare tanks.  my system is off at 175psi.  the 80 gallon tank is rated at that.  I have a 60 gal rated at 160.  it would prob be fine as I am sure there is a margin.  could change out the pressure relief, but is it worth the risk.

[metalspinner]

Interesting you brought up the pressure relief valve, doc. 
One of mine needs to be replace as it begins to leak at a certain low pressure. My guy said that someone probably used it to release tank pressure. He said to never pull the ring to hand release the pressure. This will weaken the spring loaded mechanism. 
So I'm going to replace all four pressure relief valves. 2 @70psi, 1 @ 200psi, and 1 @250psi. 

And I just ordered all the tubing and hardware for the rapidair line system. Their website has a cool CAD tool to help design your system. You can draw your building, add your compressor size, and draw the loop with drops and accessories anywhere you want. The program will suggest the best line diameter then generate a shopping list. 

And FYI, if you take that shopping list to Amazon and buy it all there, you will find the components about 20% less expensive. Some of that savings came from buying several kits and filling in the blanks with missing pieces. 

[doc henderson]

can you post your CAD drawing for us and explain the need for the number and different pressures on the relief valves. :P

[metalspinner]

Doc, the relief valves are on different components of the compressor. Each of the pistons have a valve (70psi) the very top of the pump has a valve (250psi) and the pressure switch has a valve (200psi). 

I need to log into their website to see if I saved the drawing. I did print it, but the quality might not be very good??

[metalspinner]

Well, Thier website doesn't save the drawing, but I was able to make it again pretty quick. On the design page you can toggle betwen 2D and 3D images. I didnt draw internal walls. But the loop follows the wall around.



 

 

[doc henderson]

thanks.  I still am not sure of the pressure relief setup.  if the cylinders pop off at 70, how can you get more than that total.  usually a 2 stage has a large and small cylinder, I think.  

[metalspinner]

The compressor guy explained it to me, but I cant explain it back to you. Ill take a closeup picture tomorrow of the pump and piston.

[Walnut Beast]

I am not sure if any compressor is intended to have 100% duty cycle.

My Champion as some others have a 100% duty cycle.  I doubt they are intended to be run this way.

My compressor sits outside under the shop shed.  When I wired it up I installed a relay next to it with a remote toggle switch inside to turn it off and on.  While doing that, I also put a light next to the switch by the door so I know when its on.  The light reminds me to turn the compressor off when I leave the shop.

Mine and other compressors have a valve for continuous use.     For heavy use applications such as sandblasting, the continuous run feature is available. This feature keeps main
feed line open to eliminate numerous motor starts/stops and to help cool pump.

[Old Greenhorn]

Metalspinner, just want to raise  point. The system design you showed is made for water plumbing, not air. In a properly design air system all the air drops should come off the TOP of the pipe, not the side and especially not the bottom. AT the end of each long run should be a drip leg with a bleeder valve on the end. The long run should be sloped slightly toward this drip leg. All of this minimizes the amount of condensate that can make it to the point of use. Water does get into lines and it is heavier than air, so it lays on the bottom of the pipe and providing an outlet for it, other than into your tools, is a good way to design. I understand you have a drier in the design, but nothing is perfect and I just wanted to point out this detail for others.
 I have laid out and setup several large shops over my career and it kills me to see shops with an air systems that are essentially designed to get the most water to their tools and machine as possible. Bottom and side drops are just poor design. Certainly at the very least, put drip legs at the ends of you runs. Just my 2 centavos.

[doc henderson]

if you put a T to the regulator and run some pipe on down with a valve, you can drain it.  mine never has any water in the Ts and now I rarely open the valves.  my loop is in the basement so my runs go up as described by @Old Greenhorn but I have these drains in the basement by the sump pump.  I get water in the tank with the compressor, but no where else.  I can drain the water filter at the regulators.  moisture, but no water per se.

[Al_Smith]

In extremely large compressed air systems the compressors run all the time and exhaust the air when the pressure is reached. For example where I retired from it was 2 million 600 thousand square feet with 8" main air lines at 85-90 PSI air .It's all rotary compressors now but at one time it was huge Worthington piston machines with 600 HP synchronous electric motors .16" to 24"  cylinders at about 400 RPM .You could hear the system change between pump up and idle ,noisy .
As far as a small system I'd think you could use a check valve and either a solenoid valve with a pressure switch or   just a mechanical relief valve .It should work just like the unloader valve on a small compressor which I did with a solenoid and a timer for start up .Kind of a Rube Goldberg but it worked .  8)

[metalspinner]

Old greenhorn,

This compressor has an automatic "spitter" installed on the bottom of the tank. Then that air is going through a filter/regulator on its way into the refriderated dryer before going into the piping. The entire loop will be canted for water flow at 2 opposing corners. Each drop leg has a water release valve on it. At the spray booth, I have a large dessicant cartridge filter and each spray gun has its own water filter behind the quick connect. Any piece of machinery with an pneumatic connection will have its own water filter/pressure guage.

My back up's backups have backups. ;D

I understand the Tee pointing vertically for waterflow. This system does not have an affordable option to make that U-turn back down. If condensation proves to be an issue , I will have to bite the bullet and put a U-turn at the top. After the pipe is delivered, i will experiment with its bending capabilities. Maybe I can make the turn with the pipe alone and no additional fitings??

[metalspinner]

Here is an interesting fitting from their webpage...




 


I also just read in their FAQ's the 3/4" pipe has a 6" bend radius.

[kantuckid]

I use a far less costly but effective, TP style moisture controller, augmented by a piped moisture drop with a gate valve pointed into a shop vacant spot behind a tool box. 
I also use spray gun small plastic throwaway moisture filters on jobs requiring special attention. When I sprayed a hay wagon running gear I didn't bother much as not a fussy paint job.
 
My air compressor is a 60 gallon tank C-H from Walmart and seems to have 9 lives since 1990's other than maybe 3 pressure switches and couple of heat resistant seals on the hot pipe off the pump. Cheap and enough to run my air tools.  

[Al_Smith]

There's all kinds of tricks .I've laid out 100 feet of line then teed in  a 20 gallon tank and spray painted with it .I have a trap on the gun (Binks ) plus an inline ahead of it . The 3 HP will keep up with it on painting or running an air nailer but it runs nearly all the time . That old Binks will really lay down the paint .

[doc henderson]

I have used an air bubble as a reserve when using a concreter hammer a distance away.  there is always a lag in flow/pressure with a long distance of hose.  I got a single to triple tap I think at HF

[Al_Smith]

As far as demolition work I have a Hilti TE 80 hammer drill to use on smaller stuff .Larger I just rent a compressor with a 90 pound hammer  no more than I need one .
The neatest little compressor I 've ever seen was a special unit with a small four cylinder Ford engine that ran on two cylinders and used the other two to compress ..Not a new idea because decades ago they used a Model A engine to do the same thing .BTW Ford also used a 460 V8 on larger compressors .After working 29 years where that V8 was built I've seen at least a dozen or more variations of that engine too numerous to mention . 

[doc henderson]

 

 

 

 

 

 

 

 

 


random 
 

random compressor and tank and adapters to use on the air bubble pics to follow up on the prev. comments I have made.  i went camping this weekend and just back.

[metalspinner]

I started with the install of the air piping last night. Four kits had enough hardware to get me most of what I needed. This was all supplemented with a few extras. I will have lots of leftover pipe.

This coiled pipe is a pain to deal with. I watched plenty of YouTube videos on straightening it. Long lengths just need to be fought with until they are "straight enough" or you just submit and give up.





 

 

All the hardware unpacked and the outlets preassembled



 

Each connection is taped and sealed with pipe sealant.



 

My system will be a loop. It starts here at the refrigerated air dryer then shoots up to the ceiling



 

The beginning and end of the loop is here at this tee fitting.



 

And here is the first drop to a multi outlet. This spot will be for the sand blaster.



 

Here is the multi-outlet. It has 4 ports. I only used two. This safety coupler is nice in that when the pressure is released, your fitting won't shoot out. It has a catch in it.



 

And this is where I left off last night. I'm a bit sore his morning from wrestling with the coiled pipe. It is really stiff and will hold its shape. That's both good and bad. :

[doc henderson]

is it pex?  may help to warm it and pull it out straight if you have the area.  also a tank after the cooler could improve flow if the dehumidifier restricts flow.  looks like a great system.  congratulations on going to the next level.

[btulloh]

Rapidaire piping and fittings. They make integrated air systems in 1/2" and 3/4".



Good job getting that pipe straight. I hear that's the hard part of using Rapidaire piping. 

I guess you found the kits to be more cost effective than buying ala carte fittings?

[metalspinner]

Much more cost effective than ala cart. Still needed more stuff just because I'm putting in about 15 drops. 😆

Doc,
This is the Rapid Air system. The plastic pipe has an aluminum core between layers of PE. 

 



 



  

Here is something I cobbled together this morning. And it seems to help quite a bit. It controls the coil and I use the tires of the trailer to flex the pipe straight. Both the top and sides of the tires are helpful in managing the bends. 

[Crusarius]

I highly recommend you turn the fittings so they point up, or at least flat. the way you have them, they will be a water catch.

[metalspinner]

The first corner curve. 



 



 

And the curve around each truss. The conduit clamps are needed to really hold the curvy areas. 




 

And the end of the line for today. The loop will continue above the garage then around the shop. But as you can see, I don't have the rest of the wood up yet. 



 

 Crusarious
I know, I know.  lol

To make that I turn will cost me $35 in fittings for each drop. Each outlet does have a drain valve at the bottom. I will have to just manage that manually. 



 

[Walnut Beast]

Looks nice but on where the tee is that's where I face it up and have a riser then come back down when I do copper. It keeps moisture low going to a drain point

[Walnut Beast]

They will also tell you that your air dryer should be placed farther away from the compressor. Looking good 👍 

[Crusarius]

can't you just tighten the fitting a little more to turn the QD to flat or slightly up?

[scsmith42]

Looking good MS!  That was a nice score on the compressor and dryer.

I've heard only good things about the RapidAir system, and would not hesitate to use it.

My own shop is old school - black pipe infrastructure with a 10HP IR 30 CFM compressor that I scored new for $500 (it was a Home Depot factor return because it had gotten damaged during shipment.  A forklift slightly bent, and scraped the paint off of the cage housing around the belts...).  

I had to design an unloader valve system for the compressor head so that my 30hp RPC would start the compressor under pressure in the winter.  In the summer I was fine but the thicker oil added enough resistance where the RPC just didn't have enough "oomph" to get her revved up.  

Your setup definitely looks sweet!

[metalspinner]

Update on an upgrade...
This compressor has been working really well for me. But I am hyper concerned the noise level will upset the neighbors, so I would only have the compressor operational when I would actually be using it.
Remember, I am in a residential setting.
My compressor guy came over with the muffler this week and I was able to install it yesterday.
This does 2 things for me, the first is is quiets down the compressor and the second is that it sucks air from further away from the pump. This air is much cooler and keeps the pump temp lower.



 

I'm rethinking the ceiling mount. Maybe I'll move it to the back wall?




 

And a couple of screenshots from the decibel meter readings. I was standing just 8' in front of the pump.

Before the muffler...



 


After the muffler...






But what do these readings mean? I knew I could definately hear a difference, but the readings look so similar?? So I looked it up.
It turns out that a 3dB change is twice (or half in my case) the sound difference. So this muffler halved the sound from my compressor! 8) 8)

[doc henderson]

It also appears to have changed the frequency which may change the level of sound perceived.

[Andries]

That sounds like a comment about my wife's voice. 

[rusticretreater]

Moving it to the back wall would improve aesthetics and also allow you to provide additional support to the tubes so they don't put so much pressure on the end fittings. These things vibrate a lot.

Sound is one of those funny things like electricity.  There is sound and in the case of the compressor, the pulse wave from the motor that the sound rides on.  Simply releasing the pulse wave in a controlled manner reduces the force behind the wave and thus reduces the sound level.  This also decreases the distance the pulse wave travels as it is not as sharp and powerful, to your neighbors benefit. This often produces a backpressure in the system which also softens vibrations to a degree. And as noted above, the muffler can also capture some of the higher frequencies of the sound which are particularly grating to the ear.

[metalspinner]

Rusticretreater,
With my garage door open, I can view my neighbors house about 150 yards away. The sound of the compressor isn't very loud there, but I can feel/hear a ricochet off there house. This is without the muffler. I'll need to get out there today to see. 
And most of this sound comes from the air filter cartridges both of which point outside the garage door. 

[Brad_bb]

I've owned two air compressors in my life, Both Champion.  The first was a 3hp 60gal that was rebuilt.  I had it for 25-30 years.  I replaced it not because there was anything wrong, I just wanted to go bigger to a 7.5hp (can't remember off hand if it's 80 or 100 or 120 gal).  The champions have cast iron blocks so they can be fixed/rebuilt if needed.  I'd never buy a box store compressor with the aluminum blocks.  Those are not worth rebuilding etc. and I've seen those fail. 

[Walnut Beast]

I've got a Eaton Polar Air compressor that has the whisper air that the owner patented that is a big chamber on the side of the unit that acts as your air filter and has hoses that go up to where the air filters originally go and it is absolutely amazingly whisper quiet!!!

 

 

[Al_Smith]

I don't know how many I've cobbled together from  parts and pieces .At the moment my latest endeavor is a Speed Aire compressor two stage on a 120 gallon tank with a 10 HP three phase motor .I'll need to cobble another phase converter together to run it because all I have now is a 5 HP rotary I built up .It's a back burner project because I don't really need it .
The slickest one was using a smog pump from a Ford with a 1/2 HP single phase motor .It would put out around 110 PSI and you could blow up a tractor tire but it just took a little time to do it .It didn't even have a tank on it just a check valve .Nothing to it ,clip it on ,plug it in and sit on a 5 gallon bucket and enjoy a barley pop .--it ain't rocket science ---- ;)