Air Compressor plumbing size?

Discussion in 'Garages, Workshops & Tools' started by Johnny Blaze, Jan 9, 2015.

  1. 76_TypeLT

    76_TypeLT Veteran Member Lifetime Gold Member

    Jul 26, 2008
    Houston, TX
    BTW, don't EVER use PVC pipe for compressor line. That is an explosion waiting to happen. Use steel, copper or something like Rapidair.

    You are doing right by upgrading the line to 3/4". It will improve performance drastically.
  2. zfool

    zfool Veteran Member

    May 19, 2014
    Rochester, MN
    I talked to a compressor salesman at a job I was doing last fall. They had a Big Box brand compressor 120V 50 gallon. The intended it to be for an industrial application. He said all the low price compressor makers play games with their ratings by reducing the size of the outlet. He also said you gain nothing by increasing the size of the pipe larger than your outlet. In their situation they had a 3/8 outlet with 1" copper to the "T"; and 3/4" from there. He told them they wasted allot of money on pipe. We rewired it for 230v abut I wasn't there to see the new compressor. Big Pipe is not a benefit, it wont increase your capacity was my take away.
  3. Johnny Blaze

    Johnny Blaze Veteran Member

    Jan 24, 2013
    New Washington, IN
    I had not considered going with anything larger than the compressor outlet.
    The compressor has a 3/4" outlet.

    I ended up ordering the 3/4" rapidair garage plumbing kit. I also ordered 3 regulator/ water seperators that will go at each drop.

    The 3/4" is a major step in size and strength from the 3/8" that's for sure.

    I am finishing installation now and will perform the break in procedure on the compressor.

    Hope to put it to use saturday!
  4. 71flh

    71flh Veteran Member

    Jun 1, 2010
    Nice. Just curious...
    How long are the runs and what is used to cool the air, and then remove water?
    Is the setup designed to flush water? Most systems I see have several water traps, all needing manual attention to drain. I find I'm not good at manually opening a bunch of valves everytime I want air.
    From my reading of rapidair and your description, the tube is insulated to stop corrosion, which traps heat. Thus the water separator won't work.
    Last edited: Apr 1, 2015
  5. perkalator

    perkalator Veteran Member

    Aug 27, 2014
    kennewick wa
    If your looking for a automated water trap mcmaster carr or grainger. They can be set on time delay or depending on your pocket book it will sense water in your tank and dump. We have purchased several over the years at the plant. Also pvc can be used if its rated for the pressure of your compressor. You will have to look at the specs of the pipe and what method to use on the joints by the manufacterer.The shedule 40 from home depot will blow up in your face.
    Last edited: Apr 1, 2015
  6. Goodwrench1965

    Goodwrench1965 Veteran Member

    Apr 23, 2010
    Charlotte NC
    3/8" line is fine and will deliver plenty of air for anything but sand blasting. I like cast iron pipe and if you put in new go 1/2" should support anything.
  7. Johnny Blaze

    Johnny Blaze Veteran Member

    Jan 24, 2013
    New Washington, IN
    Like I said. I upgraded compressors so I could blast.

    The manufacture recommended 3/4"

    I went with 3/4".

    I didnnot want black iron pipe due to the corrosion issues.
  8. 71Rocks

    71Rocks Veteran Member

    Oct 12, 2011
    North Texas
    Not to hijack this thread, but I'm in the beginning of building my shop. I would like to plumb the air lines using copper, but my soldering/brazing isn't that good. My next thought would be black pipe. A buddy at work has the tools to cut and thread the pipe so that isn't a problem. I know at my house all of our gas (propane) lines are black pipe. If you use a dryer after the compressor, is there really an issue with corrosion inside of the black pipe?

    I would like to hear from some of y'all that have experience with this.


  9. Johnny Blaze

    Johnny Blaze Veteran Member

    Jan 24, 2013
    New Washington, IN
    Plumbing material has been beat to death. Do a google search and you will find many discussions on the topic.
  10. Goodwrench1965

    Goodwrench1965 Veteran Member

    Apr 23, 2010
    Charlotte NC
    Yea I suppose 3/4 won't hurt. It will simply recover from air demand quicker but I honestly doubt you'd ever know the difference.. Service life on the black pipe is longer than human life unless its outside in the rain and not painted.

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