I'm getting ready to buy an air compressor, one of the 20-gallon,
belt-drive type units. I figure this gives me the largest comperssor
size I can get in a portable unit. Obivously, more air is better, and
if I need more air, the logical solution is a larger air reservoir.
My question is this: Since Schedule 40 PVC is rated to ~240 psi and
my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
pipe, cap both ends, tap one of them and hang it from the ceiling
(connected to the 20-gallon tank with a flexible hose)?
I realize that plastic is not the recommended material for compressed
air systems, but that is because hoses, etc attached to small-diameter
PVC tend to get pulled too hard and crack the plastic pipe. This is
Not A Good Thing. However, with nothing attached to the reservoir
that should get pulled on, are there any other potential problems?
Thanks,
-Phil Crow
In article <[email protected]>, Phil
Crow <[email protected]> wrote:
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
snip
Rather than typing it all out this links to a site explaining why a
larger tank probably will not accomplish much other than taking longer
to fill it:
http://sawdustmaking.com/AirCompressors/air_compressor.htm
If you do go for a second tank please get a proper metal tank approved
for that use.
FrankC
Bay Area Dave <[email protected]> writes:
>NEVER use PVC for any portion of a compressed air system.
>The plastic can become extremely brittle over time and when
>it breaks under pressure it produces plenty of shrapnel.
>Don't do it!
You might have fewer problems with the group denizens if you
were to suggest, rather than command.
For what it is worth, metal pipes also produce shrapnel when
they burst (a friend still has one black arm from cutting into
6" steel which was undergoing a pressure test at the time).
PVC embrittlement occurs primarily due to UV exposure. For
the OP purpose, a containment cage could be easily constructed
to contain any shrapnel should the PVC fail. 3/4" CDX should
be sufficient.
External physical damage to PVC (when used for the OP purpose
of air storage) can be prevented with the same containment
cage described above.
The original poster must determine the risks vs. benefits and
make his own decision.
scott
On Fri, 14 May 2004 14:07:56 GMT, Phil Crow <[email protected]> wrote:
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
I asked this of a plumber friend years ago, and he told me that it
would only be a good idea if I was tired of being alive. The repeated
cycling of pressure/release are the problem, apparently.
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
It gets pulled & pushed every time the compressor goes from off to on,
and when you use enough that it comes back on. Don't do it.
Dave Hinz
In article <[email protected]>,
Phil Crow wrote:
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
Catastrophic failure would be unpleasant. I asked in one of the physics
groups about energy storage in a compressed air tank. My 80 gallon tank
contains about the same amount of energy as a stick of dynamite.
There's a reason why no manufacturer makes a plastic pressure tank. Even
those "bladder" well tanks are metal.
On 16 May 2004 19:07:44 GMT, Greg <[email protected]> wrote:
>>There's a reason why no manufacturer makes a plastic pressure tank. Even
>>those "bladder" well tanks are metal.
>
> except the other half that are fiberglass.
...which isn't PVC either... Yes, fiberglass tanks are great, we use
them for our airpaks for the fire department. 2215 PSI rating, much
lighter than steel. Of course, they're 3 times the price, but when
you're carrying it around for 20 minutes, weight matters. For a
air storage you don't have to move around, steel is still cheaper.
Picture this - Pumpkins getting launched hundreds of feet from an air
cannon.
PVC is dangerous for compressed air. Small diameter PCV and other plastics
are fine for hoses but when used in 6" or 8" pipe!! That's a tremendous
amount of stored energy. Your 20gal tank should be addiquate. If not, many
extra storage tanks (steel) are avaliable for little money and IMHO, much
safer.
You don't live anywhere near SOCAL do you?
Dave
"Phil Crow" <[email protected]> wrote in message
news:[email protected]...
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
>
> Thanks,
> -Phil Crow
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Did you ever hear of the Darwin awards? They are given posthumously to
those who demonstrate the most unique ways to prove the theory of survival
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"Phil Crow" <[email protected]> wrote in message
news:[email protected]...
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
>
> Thanks,
> -Phil Crow
Dustmaker wrote:
>Did you ever hear of the Darwin awards? They are given posthumously to
>those who demonstrate the most unique ways to prove the theory of survival
>of the fittest.
I really don't think this would be enough for a Darwin Award
unless maybe you went an extra step or two and glued extra
shrapnel to it like maybe screws, nails, shards of glass.
Then again, it could just be me.
UA100
On 16 May 2004 12:08:38 GMT, Ed Clarke <[email protected]> wrote:
>In article <[email protected]>,
>Phil Crow wrote:
>
>> I'm getting ready to buy an air compressor, one of the 20-gallon,
>> belt-drive type units. I figure this gives me the largest comperssor
>> size I can get in a portable unit. Obivously, more air is better, and
>> if I need more air, the logical solution is a larger air reservoir.
These messages are not posted with the expectation of a reasonable
response. They are just pretending to be Tim the Toolman Taylor (Woo
woo), looking for a kneejerk.
Bill.
NEVER use PVC for any portion of a compressed air system.
The plastic can become extremely brittle over time and when
it breaks under pressure it produces plenty of shrapnel.
Don't do it!
dave
Phil Crow wrote:
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
>
> Thanks,
> -Phil Crow
Just be sure your widow, er wife, knows where you bought the PVC so she
knows who to sue for selling you something not suitable for the task.
--
Larry C in Auburn WA
"Phil Crow" <[email protected]> wrote in message
news:[email protected]...
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
>
> Thanks,
> -Phil Crow
I can show you a hole in a shop wall.
"Greg" <[email protected]> wrote in message
news:[email protected]...
> This "PVC grenade" stuff seems like a perfect subject for the guys on
> "mythbusters". They like to try to duplicate these things under controlled
> circumstances.
> I have tried to explode PVC pipe with compressed air and couldn't
duplicate the
> "shrapnel" situation.
> I will still agree a proper tank is a better option, but I would like to
see it
> proved sometime.
Lighten up boys, I just said I would like to see the guys at mythbusers take a
shot at it. If nothing else they would have some nice examples of the terrible
things that can happen.
I still say that in the grand scheme of things and the real accidents that
happen around wood shops I doubt exploding PVC lines would make a bump on the
chart.
I would worry a lt more about stuff flying off a table saw blade.
On 14 May 2004 22:46:34 GMT, Greg <[email protected]> wrote:
> Lighten up boys, I just said I would like to see the guys at mythbusers take a
> shot at it. If nothing else they would have some nice examples of the terrible
> things that can happen.
> I still say that in the grand scheme of things and the real accidents that
> happen around wood shops I doubt exploding PVC lines would make a bump on the
> chart.
The original poster was talking about making a tank out of large diameter
PVC, not just running lines.
Now I agree; airborne chunks of wood have gotten me more
than once! :) (But then again, my air system is "L" type
copper...)
dave
Greg wrote:
> Lighten up boys, I just said I would like to see the guys at mythbusers take a
> shot at it. If nothing else they would have some nice examples of the terrible
> things that can happen.
> I still say that in the grand scheme of things and the real accidents that
> happen around wood shops I doubt exploding PVC lines would make a bump on the
> chart.
> I would worry a lt more about stuff flying off a table saw blade.
"Greg" <[email protected]> wrote in message
news:[email protected]...
> Lighten up boys, I just said I would like to see the guys at mythbusers
take a
> shot at it. If nothing else they would have some nice examples of the
terrible
> things that can happen.
> I still say that in the grand scheme of things and the real accidents that
> happen around wood shops I doubt exploding PVC lines would make a bump on
the
> chart.
> I would worry a lt more about stuff flying off a table saw blade.
Lighten up? Get the facts.
I work with pressure vessels. I'm licensed to operate high pressure
boilers. My shop has an assortment of air receivers, boilers, vacuum tanks,
deaerator tanks, steam accumulators, etc. Every pressure vessel must comply
with certain specifications, fabricated by certified shops using certified
welders, must be state inspected, some licensed, all periodically inspected.
Every one is equipped with pressure relief valves (that also must be tested
periodically).
Come to my shop and I'll let one of the relief valves go. After you change
your underwear, see if you can tell me that a PVC tank is OK for air. I can
assure you the mythbuster guys would not accept such a challenge as they are
much too smart that to take a risk like that.
Ed
[email protected]
http://pages.cthome.net/edhome
On Sat, 15 May 2004 03:19:11 +0000, Greg wrote:
> Ed
> What happens when an internally rusted out steel tank ruptures?
>
The only one I've seen that rusted out got a few pinholes and wouldn't
hold pressure - so it went to the landfill rather than exploding. Of
course, that's only one...
-Doug
--
"A government that robs Peter to pay Paul can always
depend on the support of Paul." - George Bernard Shaw
> On Sat, 15 May 2004 03:19:11 +0000, Greg wrote:
>
> > Ed
> > What happens when an internally rusted out steel tank ruptures?
> >
>
That is one benefit of steel. It may rust, but it will develop a leak, a
thin section, usually the size of a dime, may blow through, but unlike
plastic, it will not explode under normal conditions. Rubber air lines are
the same way. they may split, but you don't get the flying shards. Metal can
also be inspected so there is some predictability that a tank may soon fail.
Inspection will reveal this both visually and even a simple tap on the tank
with a hammer will give a clue. Plastic is catastrophic, usually showing no
signs of impending failure.
High pressure steam is another story. The vessel can blow with force (I've
seen a brick wall taken out when the end of a boiler blew off) but the metal
itself it not nearly the problem of the hot vapor that is rapidly expanding.
Ed
[email protected]
http://pages.cthome.net/edhome
"Greg" <[email protected]> wrote in message
news:[email protected]...
> This "PVC grenade" stuff seems like a perfect subject for the guys on
> "mythbusters".
Tell that to my boss. One inch higher and he would have been missing and eye
from flying PVC shrapnel.
Greg
This "PVC grenade" stuff seems like a perfect subject for the guys on
"mythbusters". They like to try to duplicate these things under controlled
circumstances.
I have tried to explode PVC pipe with compressed air and couldn't duplicate the
"shrapnel" situation.
I will still agree a proper tank is a better option, but I would like to see it
proved sometime.
On Sat, 15 May 2004 02:01:49 +0000 (UTC), Henry E Schaffer <[email protected]> wrote:
> In article <[email protected]>,
> Greg <[email protected]> wrote:
>>I have tried to explode PVC pipe with compressed air and couldn't
>>duplicate the "shrapnel" situation. ...
>
> How many pressure cycles did you use, and how long did the pipe age
> during this test?
And (...here's the biggie...) if PVC was a viable way to make an air
tank, why would they not be on the market? It's cheaper than steel
(right? Otherwise why would it be used for plumbing?), and yet it's
not a commercial product.
Why risk it?
Dave Hinz
go back and re-read his previous post, John. His attitude
was totally uncalled for. We have a long running feud. I
hadn't posted anything that drew his smart-assed comments.
So I called him on it. And if he does it again, I'll call
him on it again.
dave
John Sellers wrote:
> "Bay Area Dave" <[email protected]> wrote in message news:Q_bpc.48538
>
>>Greg. You are so clueless! Your prideful attitude prevents
>>you from understanding something that you haven't witnessed
>>with your own eyes.
>>
>>dave
>
>
>
> Dave, how can you continue to denigrate people - not to mention the
> manner in which you do it - for whatever you've read in their remarks;
> and then get so "that way" yourself when others do the same with
> replies to your posts?
>
> Everybody has the right to express their opinion, but most people here
> agree to disagree in a civil manner. And you really are a part of the
> discussions here. Wouldn't you like to be regarded with an improved
> temperment by the group?
>
> Please chill with the 'bad' behavior.
> You'll be better for it.
>
> John Sellers
>
>We have a long running feud
We do? Damn I missed it.
I only suggested this would be a good thing for mythbusters to try. They do
prove about half the "myths" are true.
Have you ever watched the show? If this is really what everyone says it is they
could show us high speed photos of the explosions and their test dummy getting
whacked again. They also use a lot of ballistic gelatin that shows the damage
projectiles inflict on soft tissue.
I never said this wasn't a real danger, only the results of one unscientific
test which I referred to as anecdotal.
"Bay Area Dave" <[email protected]> wrote in message news:Q_bpc.48538
> Greg. You are so clueless! Your prideful attitude prevents
> you from understanding something that you haven't witnessed
> with your own eyes.
>
> dave
Dave, how can you continue to denigrate people - not to mention the
manner in which you do it - for whatever you've read in their remarks;
and then get so "that way" yourself when others do the same with
replies to your posts?
Everybody has the right to express their opinion, but most people here
agree to disagree in a civil manner. And you really are a part of the
discussions here. Wouldn't you like to be regarded with an improved
temperment by the group?
Please chill with the 'bad' behavior.
You'll be better for it.
John Sellers
"Bay Area Dave" <[email protected]> wrote in message
news:MLdpc.48605$o%[email protected]...
> go back and re-read his previous post, John. His attitude
> was totally uncalled for. We have a long running feud. I
> hadn't posted anything that drew his smart-assed comments.
> So I called him on it. And if he does it again, I'll call
> him on it again.
>
> dave
Not the point, dave. I didn't see anyone feuding with you. Neither
did I see any comments aimed at you. But your response - which IS
aimed, by the way - is degrading and maligning.
If Greg wants to believe what he said in this thread (or any other),
that may be a detriment to his health; but weighed against advice in
other posts, his opinion will be judged by all. Many will disagree,
and several will challenge. But you're usually the one who jumps in
with the childish slams. And you never seem to have the capacity for
any disagreement with your own viewpoint/opinion.
It doesn't make for civilized discourse when the group reads responses
like you made.
Go back and read what YOU wrote.
THAT'S why you catch so much shit.
From everybody.
Wise up.
John Sellers
> John Sellers wrote:
>
> > "Bay Area Dave" <[email protected]> wrote in message
news:Q_bpc.48538
> >
> >>Greg. You are so clueless! Your prideful attitude prevents
> >>you from understanding something that you haven't witnessed
> >>with your own eyes.
> >>
> >>dave
> >
> >
> >
> > Dave, how can you continue to denigrate people - not to mention
the
> > manner in which you do it - for whatever you've read in their
remarks;
> > and then get so "that way" yourself when others do the same with
> > replies to your posts?
> >
> > Everybody has the right to express their opinion, but most people
here
> > agree to disagree in a civil manner. And you really are a part of
the
> > discussions here. Wouldn't you like to be regarded with an
improved
> > temperment by the group?
> >
> > Please chill with the 'bad' behavior.
> > You'll be better for it.
> >
> > John Sellers
> >
>
Just because YOU can't duplicate the conditions leading up
to a catastrophic failure doesn't mean it doesn't happen,
Greg. You are so clueless! Your prideful attitude prevents
you from understanding something that you haven't witnessed
with your own eyes.
dave
Greg wrote:
> This "PVC grenade" stuff seems like a perfect subject for the guys on
> "mythbusters". They like to try to duplicate these things under controlled
> circumstances.
> I have tried to explode PVC pipe with compressed air and couldn't duplicate the
> "shrapnel" situation.
> I will still agree a proper tank is a better option, but I would like to see it
> proved sometime.
In article <[email protected]>,
Greg <[email protected]> wrote:
>This "PVC grenade" stuff seems like a perfect subject for the guys on
>"mythbusters". They like to try to duplicate these things under controlled
>circumstances.
>I have tried to explode PVC pipe with compressed air and couldn't
>duplicate the "shrapnel" situation. ...
How many pressure cycles did you use, and how long did the pipe age
during this test?
--
--henry schaffer
hes _AT_ ncsu _DOT_ edu
I used to work at a place that had a 20 hp compressor and we piped the air with
2" PVC. Well after about 5 years we had some repairs done to the compressor,
and the mechanic warned us about the dangers of PVC, especially "old" stuff.
Within a few months, we started having trouble with a bunch of the joints
coming loose, and we repiped with copper. After seeing this, I would never
chance using it.
[email protected] (Greg) writes:
> This "PVC grenade" stuff seems like a perfect subject for the guys
> on "mythbusters".
Enough people have had it happen to themselves (based on their
personal reports here) that it would be a short show. Here's two for
example:
http://groups.google.com/groups?selm=8u8112%24enh%241%40slb1.atl.mindspring.net
http://groups.google.com/groups?selm=34174B09.36C%40sprynet.com
I see a lot of conjecture and "I new a guy who heard a story about..."
anecdotes but no real controlled tests.
I do know that when I intentionally blew up some "baked in the sun" sch200 PVC
it was pretty unexciting. The "shrapnel" fluttered about 30' before it landed
on the ground. It wasn't even that much of an explosion, more of a
"pop-whoosh". (it was somewhere around 500PSI from a CO2 cylinder)
Certainly if it was next to your head it might have had some dangerous velocity
but it didn't go very far. Most of it stayed with the pipe.
This was a very "uncontrolled" test so I don't put it an much more than the
anecdotal category.
PVC gets brittle with age. that's why old PVC is so
dangerous in an exposed compressed air system.
dave
Greg wrote:
> I see a lot of conjecture and "I new a guy who heard a story about..."
> anecdotes but no real controlled tests.
>
> I do know that when I intentionally blew up some "baked in the sun" sch200 PVC
> it was pretty unexciting. The "shrapnel" fluttered about 30' before it landed
> on the ground. It wasn't even that much of an explosion, more of a
> "pop-whoosh". (it was somewhere around 500PSI from a CO2 cylinder)
> Certainly if it was next to your head it might have had some dangerous velocity
> but it didn't go very far. Most of it stayed with the pipe.
> This was a very "uncontrolled" test so I don't put it an much more than the
> anecdotal category.
>PVC gets brittle with age. that's why old PVC is so
>dangerous in an exposed compressed air system.
>
>dave
Age, sunlight, oil in the air from the compressor, vibration, and pressure
cycles all contribute to the degrading of PVC. It will also weaken in cold
temperatures.
I sure don't want it in my shop. Over the past few years most
mechanical-related boards I've been on have had multiple first-hand accounts of
PVC air systems blowing up. Only one or two related to iron or copper systems I
can remember.
GTO(John)
By "a lot of conjecture" you apparently mean that it hasn't happened to you.
There were two examples given where the persons were standing right there
when it happened. Is that conjecture? The fact that it happens by accident
doesn't mean anything as you can not duplicate it in a controlled
experiment?
"Greg" <[email protected]> wrote in message
news:[email protected]...
> I see a lot of conjecture and "I new a guy who heard a story about..."
> anecdotes but no real controlled tests.
>
> I do know that when I intentionally blew up some "baked in the sun" sch200
PVC
> it was pretty unexciting. The "shrapnel" fluttered about 30' before it
landed
> on the ground. It wasn't even that much of an explosion, more of a
> "pop-whoosh". (it was somewhere around 500PSI from a CO2 cylinder)
> Certainly if it was next to your head it might have had some dangerous
velocity
> but it didn't go very far. Most of it stayed with the pipe.
> This was a very "uncontrolled" test so I don't put it an much more than
the
> anecdotal category.
"Phil Crow" <[email protected]> wrote in message
news:[email protected]...
<snip>
> I realize that plastic is not the recommended material for compressed
> air systems,
Phil,
You've made your case in this one statement, then go on with yada, yada,
yada.
Please, please, please! Go to
http://www.google.com/groups?safe=images&ie=UTF-8&as_ugroup=rec.woodworking&as_usubject=PVC&lr=&hl=en
881 hits regarding PVC(a few NOT about compressed air).
How many times has this group gone over this same ground in the last year?
PVC is NOT repeat NOT suitable for compressed air!
The basic facts are that fluids under pressure and gases under pressure are
two different entities, and containment for one may not be good for the
other.
--
Nahmie
The first myth of management is that management exists.
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.674 / Virus Database: 436 - Release Date: 5/2/2004
Should make a pretty good fragmentation grenade.
"Phil Crow" <[email protected]> wrote in message
news:[email protected]...
> I'm getting ready to buy an air compressor, one of the 20-gallon,
> belt-drive type units. I figure this gives me the largest comperssor
> size I can get in a portable unit. Obivously, more air is better, and
> if I need more air, the logical solution is a larger air reservoir.
> My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> pipe, cap both ends, tap one of them and hang it from the ceiling
> (connected to the 20-gallon tank with a flexible hose)?
>
> I realize that plastic is not the recommended material for compressed
> air systems, but that is because hoses, etc attached to small-diameter
> PVC tend to get pulled too hard and crack the plastic pipe. This is
> Not A Good Thing. However, with nothing attached to the reservoir
> that should get pulled on, are there any other potential problems?
>
> Thanks,
> -Phil Crow
"Herman Family" <[email protected]/without_any_s/> wrote in message news:<[email protected]>...
> This particular setup probably won't get the darwins, at least right off.
> After all, pvc shrapnel isn't too heavy. You will have to test the system
> at a pressure greater than what you are likely to see in service. Your
> safety margin is only a factor of 2. Can you move to schedule 80 pipe?
>
> That tap is going to be a weak spot. If it decides it doesn't like it
> there, it will leave the tank in something of a hurry.
>
> I don't know if this is an acceptable setup. Given the effects of fatigue,
> and the connections, I would have my doubts.
>
> Michael
Thanks, Michael, et al. That's the kind of response I was looking
for. Reasonable, succint, informative.
I hadn't considered the deterioration issue, particularly from oil.
The reason for the post, originally, was that I had a chance to pick
up some 8" SCH 40 pipe for the right price, and figured that the air
tank idea was worth considering. Also, the 'hang it from the ceiling'
aspect is appealing. Well, back to the drawing board.
As for the rest of you, if I'd have wanted the abuse, I'd have stayed
home and talked to my mother in law.
-Phil Crow
Nothing I could do can squelch the "denizen's" smart assed
comments, Scott, yourself included.
I wasn't "commanding". The term "never" is applicable for
safety's sake. Since you take exception to my comments, all
I can tell you is, TOUGH!!
dave
Scott Lurndal wrote:
> Bay Area Dave <[email protected]> writes:
>
>>NEVER use PVC for any portion of a compressed air system.
>>The plastic can become extremely brittle over time and when
>>it breaks under pressure it produces plenty of shrapnel.
>>Don't do it!
>
>
> You might have fewer problems with the group denizens if you
> were to suggest, rather than command.
This particular setup probably won't get the darwins, at least right off.
After all, pvc shrapnel isn't too heavy. You will have to test the system
at a pressure greater than what you are likely to see in service. Your
safety margin is only a factor of 2. Can you move to schedule 80 pipe?
That tap is going to be a weak spot. If it decides it doesn't like it
there, it will leave the tank in something of a hurry.
I don't know if this is an acceptable setup. Given the effects of fatigue,
and the connections, I would have my doubts.
Michael
"Dustmaker" <[email protected]> wrote in message
news:[email protected]...
> Did you ever hear of the Darwin awards? They are given posthumously to
> those who demonstrate the most unique ways to prove the theory of survival
> of the fittest.
>
>
> "Phil Crow" <[email protected]> wrote in message
> news:[email protected]...
> > I'm getting ready to buy an air compressor, one of the 20-gallon,
> > belt-drive type units. I figure this gives me the largest comperssor
> > size I can get in a portable unit. Obivously, more air is better, and
> > if I need more air, the logical solution is a larger air reservoir.
> > My question is this: Since Schedule 40 PVC is rated to ~240 psi and
> > my 'presser only goes to 135, why not use large-diameter (6 or 8 inch)
> > pipe, cap both ends, tap one of them and hang it from the ceiling
> > (connected to the 20-gallon tank with a flexible hose)?
> >
> > I realize that plastic is not the recommended material for compressed
> > air systems, but that is because hoses, etc attached to small-diameter
> > PVC tend to get pulled too hard and crack the plastic pipe. This is
> > Not A Good Thing. However, with nothing attached to the reservoir
> > that should get pulled on, are there any other potential problems?
> >
> > Thanks,
> > -Phil Crow
>
>