Results 1 to 13 of 13

Thread: Air Compressor and Tank in different locations.

  1. #1

    Air Compressor and Tank in different locations.

    I've been badgering the neanderthals with my new-guy questions, thought it was time to head over into the world of electrons.

    I'm laying plans for converting my two car garage (we park the cars in the driveway, only need to store kids bikes and things in a small section of the garage) into a wood shop/sanctuary for myself.

    Despite having most of the garage, I'm still thinking I'm turning up short on space. I want a cyclone and an air compressor, but am having trouble fitting both in the part of the garage I want to dedicate to the noisy stuff.

    I was reading a Taunton book on Shops by Szandor Nagyszylansky where he mentions enhancing your small compressor with external tanks, and that's where a light flickered on over my head.

    Has anyone done this? Campbell Hausfeld is located here in Cincinnati and I'm pretty sure they have a factory store. If I could find an inexpensive but powerful compressor, would it be possible to put that in the garage, probably hanging securely from the ceiling to get it out of the way, and then plumb with, say, black pipe through the footers of the wall between the garage and house into the basement where I'd locate a large tank?

    If I think this through right, the SCFM of a compressor is based on it's duty cycle more than anything. My 6gal PC mini compressor could only handle small amounts because it couldn't run continuously, But if there were, just to be silly, a 250 gallon tank compressed to 135psi, it would allow me to pump out 90psi for a considerable time before the pump had to kick in.

    Would I even need a tank at all in the garage? Would there be any reasonable and SAFE way to buy just a CH compressor and plumb it direct into the big tank by 20ft of black pipe?

    I could be wrong in my thinking here, but this sounds like it would give me the best of both worlds, noise out in the garage, big tank in my 1000sf basement that's really just spending time holding boxes right now.

    And, since I'm on the subject, has anyone every tried to soundproof a compressor by putting it in an sound insulated box? I realize you need a considerable amount of air inflow, and they do have a tendency to heat, but perhaps if you could include some sort of insulated incoming duct, maybe fan driven, would that work?

  2. #2
    Join Date
    Sep 2003
    Location
    WNC mountains
    Posts
    143
    I do not see any problem with remote tank as long as safety is taken into consideration. The source of pressure(compressor), pressure switch, pressure relief valve, and tank MUST NOT HAVE A CUT OFF VALVE BETWEEN THEM. Pressure relief valve must not be able to be isolated from system.. Condensate from the humidity in air must drain down hill to a drain point. No point in the system should be exposed to freezing temperatures. The trapped condensate will freeze and burst pipes. Considerable cooling will be necessary to keep an enclosed compressor from overheating. Discharge temps can easily approach 200°F. Overheating compressor will vastly shorten bearing, discharge valve, and oil life. The higher the discharge pressure, the higher the temperature.

    Good luck
    Bill in WNC mountains

  3. #3
    Join Date
    May 2004
    Location
    Oakland, MI
    Posts
    494
    Bill has given you very good advice. Where I work, we use storage tanks somewhat removed from the compressors (they are 100HP!). When you get down to it, your black pipe will just be part of the storage tank as far as the compressed air is concerned. The only problem with a small compressor and an oversized tank is if you have leaks that will bleed off pressure between uses. This would cause that little compreesor to have to re-create the maximum pressure before it would get a rest. In other words, if you have a 5 gal. tank and lose it all you only need to re-fill that small tank. If you have 100 gallons and lose it (to leaks) then you might need to wait for a long time before you have useful pressure again. I would use a tank that is pretty much normal for the size compressor you get but I would not worry about splitting them up, as long as you follow Bill's good advice about plumbing, wiring, and safety valves.

    Greg

  4. #4
    Join Date
    Feb 2003
    Location
    Hayes, Virginia
    Posts
    14,762
    You must use an ASME certified tank, all of the welds are radiographed and the welds meet very high standards. Look at any compressor today and you will find a metal plate welded to the tank with an ASME stamp.

    Please don't forget that a high pressure air tank is a bomb and can cause catastrophic damage to your home and shop or both. The larger the tank the higher the risk, a twenty gallon tank at 90 psi can totally destroy a two car garage.

  5. #5
    Join Date
    Feb 2003
    Location
    Griswold Connecticut
    Posts
    6,927
    Chris. I'll attempt to give my .02 here. Hopefully I don't shame Mr Pascal or Mr Bernoulli. The use of "external" tanks is a strategy to eliminate pressure drops in an air sysyem. If you think of an air system as a loop the placement of additional tanks will give you a surge volume and mitigate pressure drops in a system. This will also to some small degree cut down on the duty cycle if the sysyem is tight, if it is not tight it will increase the run time between duty cycles. The SCFM rating is an indication of the size of the loader and unloader valves and the physical dimension of the compression piston chamber. The duty cycle is an indication of the amount of time between load cycles that the compressor is rated for. It doesn't really matter where the storage tank is in relation to the actual compressor itself, but the length of the run will have an effect on operation because it will act as an additional reserve volume. If you were to charge the system to 135psi you would get some additional benefit, but only on the first few uses of a tool before the pressure drops, and kicks off the compressor then you would be dependent on the load time to keep your system at 135psi. I know that alot of people use "black pipe" for air systems to avoid sweating joints, but the proper material is ASTM B-66 or higher seamless copper pipe.This is for a few reasons: Copper is more resistant to internal corrosion from moisture products in the system. The Reynolds numbers(friction of the process on the internal walls of the pipe) for copper pipe are better than black pipe and the failure mechanism for copper tubing at burst pressure is a "rip" along the longitudinal axis, black pipe on the other hand is a little more severe. it just blows out the segment where the failure occured. If it is the noise that you are trying to mitigate you might want to consider putting the compressor and the tank outside and using 3/4"-1" copper pipe to bring the air into your shop. If you put the compressor in a large enough box it should work,ie small closet, but instead of trying to block all the noise just try to deflect it away using sound barriers between the compressor and you.
    Take Keiths comments to heart about the kinetic energy in a pressurized system. even your small 6 gallon compressor has thousands of pounds of total force inside the tank. Make sure that any system you put in has proper reliefs and is rated for the pressure you want to run it at, and don't buy those cheeseball CH tanks that are at Wal Mart, those are for recharging the bladders in well pump tanks( 35-50 psi) not for long term use in an air system. Addy Protocol. 25 years of experience with high pressure gas and fluid systems, and low pressure air supply systems.

  6. #6
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    65,695
    It might make more sense to buy a nice 60 or 80 gallon compressor and locate it in the basement and pipe TO the shop and garage. That gets the machinery out of the shop for more woodworking room and reduces noise in the shop, too. If you put it in a closet with sound baffling, you'll also not hurt the noise level in the house too much, too. (Putting my 60 Gallon IR compressor in the DC closet which is well-insulated was one of the best things I ever did...I hardly notice it when it runs.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  7. #7
    Join Date
    Feb 2004
    Location
    Celina, Texas
    Posts
    40
    I agree with Jim Unless you need a lot of air. I guess I would want to know more about your requirments to help everyone make a better decision.

  8. #8
    I would use copper! black pipe will rust and will give you problems with your tools.

    Jim

  9. #9
    Join Date
    Feb 2004
    Location
    Odessa, Texas
    Posts
    1,567
    If you are worried about both Space and Noise, if you have the funds, you might consider spending a bit more and getting one of the "Slow Turning", (around 1200 RPM) Quincy Compressors, which are "MUCH Quieter" than the higher RPM compressors, and then install the whole unit in the basement and just use copper pipe (as mentioned above), to pipe it up to the Garage/Shop.

    With this setup, you probably wouldn't need to worry about an enclosure for noise abatement.
    "Some Mistakes provide Too many Learning Opportunities to Make only Once".

  10. #10
    Join Date
    Jul 2003
    Location
    Midland, Michigan
    Posts
    453
    My 6gal PC mini compressor could only handle small amounts because it couldn't run continuously, But if there were, just to be silly, a 250 gallon tank compressed to 135psi, it would allow me to pump out 90psi for a considerable time before the pump had to kick in.
    If you are already limited by duty cycle I can't see where the larger tank will be of much help. 50% duty cycle means (to me anyway) that you operate the compressor no more than 30 minutes out of each hour. If you couldn't pump up a 250 gallon tank to 135 (say for discussion) in a half hour it would require a timing device that would shut down the compressor for 30 minutes before you could resume the pump-up. Likewise as you start to drain the system (assuming you ever got it fully charged) and the cut-in pressure is reached the compressor will start to recharge the system but again you will be limited to 30 minutes of operation (50% duty cycle) before it will be necessary to shut it off to save the compressor from destruction. Very good compressors have 100% duty cycles and can handle additional reservoir space. I'd suggest that if you need this much air - you have the wrong compressor.

    Other comments;

    ASME tanks are not a requirement always and everywhere. I'd be in favor of it if they were. Your insurance provider may require ASME tanks even if local code and State law doesn't.

    If you had priced a 250 gal. ASME tank in advance, we probably wouldn't be responding to this question.
    Work safe, have fun, enjoy the sport.
    Remember that a guy never has to come down out of the clouds if he keeps filling the valleys with peaks. Steve

  11. #11
    Join Date
    Feb 2005
    Location
    Mont. Co. MD
    Posts
    973
    Quote Originally Posted by Chris Thompson
    I've been badgering the neanderthals with my new-guy questions, thought it was time to head over into the world of electrons.
    I wandered over there once by mistake, it was all damp and dark and musty smelling.

    I have my compressor located in the basement utility room. It is plumbed to both the garage, and the workshop in the basement which are on opposite ends of the house. I used 3/4" copper pipe throughout to minimize pressure drop. As a good measure, I placed "drip drops" with bleeders at the bottom of every vertical. You can see a picture of the compressor and shop in this thread. I considered adding a tank to the garage, to compensate for pressure dorps, but have not found it necessary. And yes I do use air tools in the garage.
    The compressor is a big old, slower RPM, 2 stage cast iron pump that is pretty quiet. Becasue it is located below my wife's office, It could still use some more sound control.
    Using copper makes for a very tight air system. I can't say it doesn't cycle at all when idle, but it can go at least 2 weeks without topping off.
    As far as what you are suggesting, that is a compressor in the garage, and the tank in the basement, I do have some additional thoughts on that idea. First of all, the difficulty is the pressure switch. As someone else suggested, If located at the compressor, you have to maintain an open line between the tank, and the pump. I will go one step further and suggest that you need a separate line just for the pressure switch, so it would not react to "local" pressure. On the other hand, the best solution is to locate the pressure switch at the tank.
    I can give you one other good reason for locating the both the compressor pump, and the tank in a basement. It's dry. I get hardly any water in my system becasue it is in a conditioned space.

  12. #12

    Wink air compressor

    i tryed using my emglow to 1 1/2 hp with 4 gallon tanks to fill my 60 gallon tank that the motor burned up but the emglow got hot from runing so much.It is better to get a larger compressor and put in outside in a small building and pipe the air inside.I built a 4x12 building along side my shop and put my 60 gallon compressor and my dust collector in and still have some room for storage.my 02 cents.It is a lot guiter not being in the shop also Mike

  13. #13
    Join Date
    Apr 2005
    Location
    Anywhere it snows....
    Posts
    1,458
    What you suggest is a great idea. Many old timers actually did this. I have seen very large, single cylinder pumps run from line shafts and none of these ever had reciever tanks attached to them. The tanks were all separate.

    Tanks can rupture or they can explode. There are three ways to get your clock cleaned on a tank. 1). Rust damage from condensate within the tank. This usually goes to work on the interior edges of the welds and results in tiny pin holes opening up. These failure modes dont usually explode. 2). The tank becomes a fuel-air bomb. Many pumps use oil for lubication and this oil vapor mixes with air inside the reciever tank. As the pump is used to hard, the air temperature of the pump outlet can exceed ignition temperature of the compressed oil-air mixture and the tank explodes like an M-80 on hyper steriods! This risk can be reduced by using a approved compressor oil and not pushing the compressor beyond its duty cycle. If you dont have enough air, get a larger compressor. Also note that many shops that paint stuff use compressor re-breathers for personel. Companies like SATA make awsome re-breathers with complete OSHA certification. These clean the air and make it breathable. What they do not do is remove CO. The main source of CO in compressor systems is from partial combustion of lubrication oil in compressors being run over their duty cycles. This CO can kill you but then we all knew that. 3). The last source of rupture failure is from faulty cutouff valves. If the cutoff valve does not work or is not installed correctly, the compressor has no way of shutting off. If all your tank safetys are not working and the pump is allowed to exceed the ASME pressure cutoff for that tank, the tank can and will eventually explode violently. So **YOU** need to double check your pressure cuttoff valve and any emergency pop off valves as well on a routine basis. And they are not all the same. The pop off valve on my compressor is 175 PSI whereas the pressure cuttoff switch is 125 PSI and the regulator pressure is 90 PSI.

    I personally do not want the reciever tank inside the shop. Mine is 120 gallons and that takes up lots of space. Also, I have a large old iron pump and between the compressor and the phase converter, I have to yell for anyone to hear me! I have also seen what is left of a shop with drywall walls after an 80 gallon tank exploded. It scalloped the walls by pushing the drywall inbetween the studs. Good thing nobody was in there.

    Right now, I am moving all my support stuff into a small shed on the side of the shop. All electrical stuff, the phase converter, the 240 to 440 three phase transformer, all three service centers, my air compressor, my aux hydraulic power pump, etc. The only issues I have gotten from the inspectors were the circuit runs between the two buildings. If you do this, it really makes life easier to build this shed as an add on to the shop instead of a separate structure about 2 to 3 feet from the main shop structure. I am working out a scheme to build a connection between the two now that both looks good and satisfies the inspection dude. Not to bad but it would have been easier if I had known about this issue before the frameup of the shed. For us, our community uses the NEC code. No extra loco local codes.

    So I would consider doing something similar. In your case, you can put your DC and compressor in the same structure which would be a lean to add on to your garage shop. Later you can add on some three phase stuff including your converter if that need should arise.

    Another thing to consider is this. Your compressor air lines should made from black gas pipe. Make sure you install the horizontal runs on slight pitches *AWAY* from the compressor. The air taps should be taken off of the main supply line such that the supply line lies below the air connectors. TIP tools has some helpful diagrams in their catalogs on how to install shop air lines. The main choice of black iron is that black iron keeps cool and allows moisture to condense. The grades help condensed moisture to run to a single low point where it can be drained from the system. You do not want line condenstate to drain backwards into the compressor tank. Also make sure you tank has a good drain on it was well.

    Keep in mind that normal fittings for black gas pipe are rated to about 150 PSI. These are actually schedule 40 fittings even though the schedule 40 nomenclature does not mean much with respect to these fittings. As I have sections that run at full 175 PSI to supply a water supply compression tank several hundred feet from the shop, I have had to use some schedule 80 fittings. These can hold up to 300 PSI. The standard black pipe can safely hold 175 PSI. Most of these systems will run regulated air at about 90 PSI. As long as your regulator is working fine, you should not have any issues with standard fittings.

    Some folks have used PVC and copper. I think PVC for air supply lines is just a dumb idea and I will not comment any further here. The copper works fine if your pressure is 90 PSI or less. Our old lab had sweated copper air lines. But if your going to 125 PSI or more, you may wish to avoid these as the joints can blow themselves apart.

    Hope this all helps a bit...
    Had the dog not stopped to go to the bathroom, he would have caught the rabbit.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •