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Compressed air piping.

MikeL_2MikeL_2 Posts: 187Member
I've finally convinced a good friend that the 1" PVC piping in his woodshop is dangerous. I don't do much of this type of piping; what is most commonly used?

Comments

  • pecmsgpecmsg Posts: 846Member
    What pressure?
  • MikeL_2MikeL_2 Posts: 187Member
    120 psi
  • GroundUpGroundUp Posts: 578Member
    I typically cut and thread schedule 40 black or galvanized for compressed air. Some codes will call for type L copper- sometimes soft soldered, sometimes pressed, occasionally silver soldered, usually brazed to eliminate cracked joints from vibration. My shop at home is soft soldered for ease of install, and I would do it again.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,951Member
    copper tubing soldered would be the best way to go. I don't think pvc is allowed on compressed air
  • hot_rodhot_rod Posts: 11,753Member
    rapid air products.com has a few different plastic piping options
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • MikeL_2MikeL_2 Posts: 187Member
    Thank you, everyone!
  • Solid_Fuel_ManSolid_Fuel_Man Posts: 1,647Member
    I see a lot of DIY use PVC for compressed air. It seems to hold up for a few years and then deform. It's technically good with the pressure, but I believe the oil and heat from the compressor is what kills it.

    I use soft soldered copper in my own shop. Heat water and oil wont hurt that!
    Serving Northern Maine HVAC, and Controls
  • FranklinDFranklinD Posts: 399Member
    I’ve used the RapidAir system in my garage shop with good results. It’s essentially just the same nylon tubing used in truck air brake systems, seems to hold up well - no issues in the last 3 years. I went with it for ease of install and ease of future modification/expansion. That said, my go-to has usually been threaded black pipe.
    Ford Master Technician, "Tinkerer of Terror"
    Police & Fire Equipment Lead Mechanic, NW WI
    Lover of Old Homes & Gravity Hot Water Systems
  • GilmorrieGilmorrie Posts: 106Member
    PVC for 120-psi compressed air? How are the joints made up, and what is their risk? Personally, I would use steel pipe and fittings.
  • hot_rodhot_rod Posts: 11,753Member
    The issue with PVC is it turns into sharp shrapnel like pieces when it let's go under pressure.

    There are some composite piping systems I've seen in commercial shops, push type fittings. Look like Aquatherm piping.

    Kaeser Smart Pipe is an aluminum tube system I have seen in trucking repair shops in my area.

    Pex Al Pex is another option.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • VoyagerVoyager Posts: 222Member
    Pex works well if you don’t mind ugly. I personally would not use it in my shop. I am looking at installing an air system also and will use copper as I can easily install it myself. Iron pipe is the most robust option, but internal rust is always an issue. The aluminum piping systems are nice, but pricey.

    As Hot Rod said, the issue with PVC is the failure mode. If PEX or copper fails, it will just split in one place with no flying pieces. PVC just isn’t sufficiently ductile.
  • ZmanZman Posts: 5,051Member
    I did a buddies shop with steel threaded pipe. No issue 12 years later. Be sure to put a dryer on the compressor and drip legs with drains at low points.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • LeonardLeonard Posts: 840Member
    PVC is brittle and when it breaks it makes very sharp jagged shrapnel. In late fall cool NH weather I smashed some 2inch PVC with a sledgehammer........very sharp pieces.
  • VoyagerVoyager Posts: 222Member
    Zman said:

    I did a buddies shop with steel threaded pipe. No issue 12 years later. Be sure to put a dryer on the compressor and drip legs with drains at low points.

    I would also add a filter at each port to be sure. The issue isn’t so much moisture as it is flakes of rust after a few years that will begin to come off. Even a good drier doesn’t get the RH to 0 so light rust will form and eventually come off in small flakes that can cause issues with paint sprayers and such. Probably won’t cause much harm to larger air tools.

    Steel is the most robust, but copper and aluminum are much cleaner if you are doing spray painting. For only air tools, steel is probably fine.
  • ChrisJChrisJ Posts: 10,032Member
    > @hot_rod said:
    > The issue with PVC is it turns into sharp shrapnel like pieces when it let's go under pressure.
    >
    > There are some composite piping systems I've seen in commercial shops, push type fittings. Look like Aquatherm piping.
    >
    > Kaeser Smart Pipe is an aluminum tube system I have seen in trucking repair shops in my area.
    >
    > Pex Al Pex is another option.

    Why pex-al-pex and not normal pex?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • LeonardLeonard Posts: 840Member
    As a kid in dad's garage we wanted to extend the air line. I found a long steel pipe bent it up to fit in pickup truck bed. Hammered it straight and noticed inside had a LOT of rust . I just put a filter on the outlet. Used the air for body work tools and paint gun for shooting cars.
  • ChrisJChrisJ Posts: 10,032Member
    > @Leonard said:
    > As a kid in dad's garage we wanted to extend the air line. I found a long steel pipe bent it up to fit in pickup truck bed. Hammered it straight and noticed inside had a LOT of rust . I just put a filter on the outlet. Used the air for body work tools and paint gun for shooting cars.

    Erm
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • rick in Alaskarick in Alaska Posts: 877Member
    Run it in galvanized and you won't have to worry about the rust issue. The galvanized that is out now does not have the flaking issues like before. Galvanized is all I am using on my gas piping as I can't stand rusty looking pipe, which around here takes about a couple of weeks.
    Rick
  • LeonardLeonard Posts: 840Member
    The old galvanized I found discarded in a hole ~ 50 years ago was only galvanized on the outside.
  • Leon82Leon82 Posts: 618Member
    There are extrusion setup where you tap it after you cut it an put an oring sealed end on.

    Others are aluminum tube with a shark bite type fitting you screw on
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