[AT] Air lines for shop

Henry Miller hank at millerfarm.com
Mon Sep 13 12:02:54 PDT 2021


I have.  My dad bought a compressor when I was a kid, and 30 some years latter he had to replace it.

-- 
  Henry Miller
  hank at millerfarm.com

On Mon, Sep 13, 2021, at 14:00, Stephen Offiler wrote:
> I get that, and it sounds reasonable, but let me ask the next question:
> have you ever seen a tank fail due to rust?
> 
> SO
> 
> On Mon, Sep 13, 2021 at 2:53 PM Henry Miller <hank at millerfarm.com> wrote:
> 
> > I don't drain my tanks as religiously as I should.  Too often it is turn
> > the compressor on, fill a tire, turn it off, leave it for a month before I
> > have the next tire to fill.  Thus I really want water to not get into my
> > tanks in the first place.  I want it to collect someplace cheap and easy to
> > replace: not the tank.
> >
> > --
> >   Henry Miller
> >   hank at millerfarm.com
> >
> > On Mon, Sep 13, 2021, at 13:22, Stephen Offiler wrote:
> > > I am not arguing your point, but just observing that a cooler installed
> > > between the pump and the tank is not something you see every day unless
> > > it's a factory-built unit in the form of a fan-cooled radiator.   These
> > > don't have water drains, either.  Why try to keep water out of the tank?
> > > Reduced tank corrosion comes to mind; anything else?  One problem with
> > this
> > > idea is that the air coming out of the pump is HOT.  Whatever cooler you
> > > install has to be rated for high temperature.  I know I ran into this
> > when
> > > I was spec'ing the chiller I recently installed on my 5HP compressor at
> > > work.  The ones I looked at all generally had low input air temp rating;
> > > around 140F was max, and some were 120F.  I vaguely recall one rated for
> > > 250F and the cost on that unit was easily double.  Just curious.
> > >
> > > SO
> > >
> > > On Mon, Sep 13, 2021 at 12:48 PM Henry Miller <hank at millerfarm.com>
> > wrote:
> > >
> > > > If you are worried about water (and you are right to worry) put your
> > > > compressor as far from where air will be used as possible, and use a
> > big
> > > > pipe close to the compressor.  You want the air to move very slow near
> > the
> > > > compressor so as much water as possible drops out there.  Make sure you
> > > > properly take all the air off the top of your overhead pipe, and slope
> > that
> > > > pipe to a drain.
> > > >
> > > > If possible put a air cooler with a drain between your tank and the
> > pump:
> > > > keep the water out of the tank if possible.
> > > >
> > > > --
> > > >   Henry Miller
> > > >   hank at millerfarm.com
> > > >
> > > > On Mon, Sep 13, 2021, at 10:19, Spencer Yost wrote:
> > > > > One of the reasons I have been thinking copper is because here in the
> > > > > humid south, water in air lines is a problem.  You can not paint
> > without
> > > > > a desiccant filter for example. Nothing worse than seeing water
> > droplets
> > > > > coming out with your paint (been there done that).  One benefit I
> > > > > thought copper would have would be  to condense water quickly and
> > > > > earlier in the run; therefore water vapor would be less of an issue
> > at
> > > > > the tool end(assuming I slant the lines to run back towards the
> > > > > compressor) and my tool-end water filters wouldn't fill up so fast.
> > > > >
> > > > > Anyone with experience with copper find this to be true?
> > > > >
> > > > > Also, copper is less than $1 per foot more expensive(3.46/ft vs
> > 2.69/ft)
> > > > > so for a run that will be less than 100' worth of pipe so I decided
> > to
> > > > > not sweat (excuse the pun) the cost factor between black pipe and
> > copper
> > > > > and just go on the merits.
> > > > >
> > > > > While continuing to look around at various options and along the way
> > I
> > > > > saw 1-1/2" black pipe at Lowes with an oddly specific PSI rating:
> > > > > 231PSI    I'm beginning to think Brice might be right and they are
> > using
> > > > > steam rating....
> > > > >
> > > > >
> > > > > Spencer
> > > > >
> > > > >
> > > > >
> > > > > On 9/13/21 9:55 AM, Stephen Offiler wrote:
> > > > > > Brice reminded me of something.  Now, it's been a while since I've
> > put
> > > > > > much thought into Schedule rating of pipe. Reviewing, the basic
> > > > > > definition is:  Schedule = Pressure/Stress.  Example:  Schedule 40
> > > > > > pipe at 1200 psi would have stress of 30 ksi developed in the
> > walls.
> > > > > > That's why wall thickness increases with pipe diameter - larger
> > > > > > diameter means larger internal surface area means higher force for
> > a
> > > > > > given pressure, so wall thickness is increased to fight the higher
> > > > > > forces and keep stress in the wall constant.    I pick the example
> > > > > > above because Schedule 40 Class A pipe has a yield stress rating
> > of 30
> > > > > > ksi.  (There is also a Class B which is somewhat stronger).   At
> > 175
> > > > > > psi  your factor of safety is almost 7, which is quite large.  I'd
> > > > > > sleep well with this number as small as 4 - in other words, 300psi.
> > > > > > Of course there's additional considerations for the fittings and
> > > > > > whatnot, but as long as it's Schedule 40, there's really nothing to
> > > > > > worry about.
> > > > > >
> > > > > > That stuff at Lowe's claiming 150 psi.... I don't believe it.  The
> > > > > > people writing up the specs on their website are probably
> > minimum-wage
> > > > > > drones.  I would get ahold of a chart showing wall thickness vs
> > pipe
> > > > > > diameter and measure the wall thickness right there in the store
> > (yeah
> > > > > > I do tend to travel with a caliper in my bag most of the time).
> > > > > > Dimensions alone would confirm if this "150 psi" stuff is actually
> > > > > > Schedule 40.
> > > > > >
> > > > > >  I know you don't really want to use black iron pipe but I like I
> > said
> > > > > > Brice sort of reminded me of how all this pressure rating stuff
> > > > > > works.  Of all the options, black pipe is certainly the most
> > > > > > old-school, antique-tractor appropriate. I'm not against the modern
> > > > > > materials and I would also seriously consider Pex, but not PVC.  I
> > can
> > > > > > solder copper way faster than I can screw together black pipe but
> > > > > > copper is pretty darn pricey these days.  In my own shop, the
> > answer
> > > > > > is:  rubber hose.  I've never graduated past the portable
> > compressor
> > > > > > to something big and stationary that lends itself to permanent
> > > > plumbing.
> > > > > >
> > > > > > SO
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > On Sat, Sep 11, 2021 at 11:43 AM Brice Adams <
> > brice.adams at gmail.com>
> > > > > > wrote:
> > > > > >
> > > > > >     Spencer,
> > > > > >     Something tweaked my memory from plumbing the Huber about
> > > > > >     different pressure ratings for steam, air, and fluids with
> > > > > >     schedule 40 and 80 pipe.  The 150 psi may be the steam rating
> > and
> > > > > >     the air rating is 34 to 6 times higher.
> > > > > >     Brice
> > > > > >
> > > > > >     On Sat, Sep 11, 2021 at 8:21 AM Ken Knierim
> > > > > >     <ken.knierim at gmail.com> wrote:
> > > > > >
> > > > > >         Go copper if you're comfortable with sweating it together.
> > I
> > > > > >         did that after trying PVC for awhile. Got some AZ sun on
> > the
> > > > > >         PVC and it blew out a couple times with sharp little shards
> > > > > >         flying around (doesn't survive impact damage well). I like
> > the
> > > > > >         sound of PEX but again, sunlight is abundant here.
> > > > > >         My $0.02
> > > > > >         Ken in AZ
> > > > > >
> > > > > >         On Fri, Sep 10, 2021 at 6:43 PM Spencer Yost
> > > > > >         <spencer at rdfarms.com> wrote:
> > > > > >
> > > > > >             So I’m going to be making three new pipe runs from my
> > air
> > > > > >             compressor. Previously I’ve just relied on hoses since
> > the
> > > > > >             50 foot hose will reach everywhere in my shop.
> > > > > >
> > > > > >             It will consist of one long “trunk” run that will be
> > > > > >             nearly 40 feet, and then a few stub runs of anywhere
> > from
> > > > > >             5’ to 15’
> > > > > >
> > > > > >             I was thinking about black pipe as that’s what I have
> > used
> > > > > >             before. But I had no idea the common, affordable black
> > > > > >             pipe you find in hardware stores is only good to 150
> > psi.
> > > > > >             My compressor is two stage and is 175 psi:
> > > > > >
> > > > > >             3/4-in x 3-ft 150-PSI Black Iron Pipe
> > > > > >
> > > >
> > https://www.lowes.com/pd/Southland-Pipe-3-4-in-x-3-ft-150-PSI-Black-Iron-Pipe/3371442
> > > > > >
> > > > > >             I guess I’m thinking about biting the bullet and going
> > > > > >             copper. I’d like to go with some of those really neat
> > new
> > > > > >             aluminum systems but I could never afford that.
> > > > > >
> > > > > >             What are y’all think about copper? I know 3/4” copper
> > is
> > > > > >             good to about 1000 psi.   It eliminates  the rust
> > problem
> > > > > >             that eventually befalls all black steel pipe systems;
> > > > > >             which is kind of a plus.  As far as installation, I
> > solder
> > > > > >             better than I cut threads :-)
> > > > > >
> > > > > >
> > > > > >
> > > > > >             Spencer
> > > > > >
> > > > > >
> > > > > >             Sent from my iPhone
> > > > > >             _______________________________________________
> > > > > >             AT mailing list
> > > > > >             AT at lists.antique-tractor.com
> > > > > >
> > > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > > > >
> > > > > >         _______________________________________________
> > > > > >         AT mailing list
> > > > > >         AT at lists.antique-tractor.com
> > > > > >
> > > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > > > >
> > > > > >     _______________________________________________
> > > > > >     AT mailing list
> > > > > >     AT at lists.antique-tractor.com
> > > > > >
> > > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > AT mailing list
> > > > > > AT at lists.antique-tractor.com
> > > > > >
> > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > > >
> > > > >
> > > > > --
> > > > > Spencer Yost
> > > > >
> > > > > _______________________________________________
> > > > > AT mailing list
> > > > > AT at lists.antique-tractor.com
> > > > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > > >
> > > > _______________________________________________
> > > > AT mailing list
> > > > AT at lists.antique-tractor.com
> > > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > > >
> > >
> > > _______________________________________________
> > > AT mailing list
> > > AT at lists.antique-tractor.com
> > > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > >
> > _______________________________________________
> > AT mailing list
> > AT at lists.antique-tractor.com
> > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> >
> 
> _______________________________________________
> AT mailing list
> AT at lists.antique-tractor.com
> http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> 



More information about the AT mailing list