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another compressed air pipe question

D

dexter-

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Emerald, Pennsylvania
Can black pipe be buried underground? I have an existing black iron piping system in my basement that i want to extend to a detached garage. I was considering using black pipe to extend the system because copper prices are way too high. Can I use it inderground or will I have corrosion problems? I am alo considering using a rapid air product called Duratec, but for cost reasons would rather use black pipe. Also, my exisiting pipe run is 1/2" ID about 40 ft long. After I extend out to the garage with 1/2" pipe the total run will be about 100- 125 ft. . I wont be using any air tools out there, just basic blow guns and tire filling. Any concerns about too much pressure loss because of the smaller diameter pipe for a run this long?
 
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mdbeck1

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Subscribed.

I'll be doing a similar thing in the near future but was planning on running 3/4" galvanized since I have 3/4" connectors coming out of the compressor.

I also plan on putting a cut off on the air line from inside the garage and a filter/regulator in the garage and the out building.

Oh, and I'm a little bit more ambitious than you. I plan on running air powered sanders and maybe spraying some finish.
 
OP
D

dexter-

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Emerald, Pennsylvania
i have a turbine driven HVLP system, so i really dont need the hassle of using compresed air. I use electric sanders mostly. Just never got into the air driven sanders.:)
 
G

gorilla

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I ran a 40" long air line from my compressor in the garage to my machine shop in gas pipe.It's coated with a plastic coating and is intended to be buried. I don't think it's much more expensive than black pipe.
 
D

djjsr

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Black pipe will eventually corrode underground. How long it takes probably depends on soil and moisture conditions. I've read that coating the pipe with tar is effective. Maybe that spray automotive undercoating?
 
A

AZAV8

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Mesa, AZ
DO NOT use PVC. Even underground it can rupture due to the air pressure. Never, ever use PVC for compressed gas systems.

You should use galvanized underground. As an extra measure of corrosion resistance, sleeve the pipe with the polyethylene they sell for underground copper so you can tell the difference between the hot and cold, the orange and blue stuff.
 
V

VWandDodge

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May 20, 2011
Messages
951
AZAV8 said:
DO NOT use PVC. Even underground it can rupture due to the air pressure. Never, ever use PVC for compressed gas systems.

You should use galvanized underground. As an extra measure of corrosion resistance, sleeve the pipe with the polyethylene they sell for underground copper so you can tell the difference between the hot and cold, the orange and blue stuff.
Click to expand...

Unfortunately, this forum is rife with rocket surgeons who are convinced PVC can or should be used in compressed air systems. I would be the first to laugh when the pipe shattered and sends damaging shrapnel everywhere.
 
C

Charles (in GA)

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50 mi south of Atlanta
AZAV8 said:
DO NOT use PVC. Even underground it can rupture due to the air pressure. Never, ever use PVC for compressed gas systems.
Click to expand...

Normally, I never recommend PVC, it is not safe for use for compressed gasses due to the physical characteristics of the PVC when it ruptures, but this is underground.............. what happens should it rupture? hmmm.... "compressor seems to run alot when I turn the air valve on"

The issue with PVC is it is not damage tolerant under pressure. It explodes, scatters shrapnel everywhere, usually when impacted, sometimes on its own. also, PVC is not ultraviolet resistant, and sunlight over time damages exposed PVC................ but, its underground, it won't spread shards of plastic, its not likely to get impacted or damaged, and its not exposed to sunlight.

In a few years, the OP might have it rupture, and might have to dig it up, if he still lives there...............

Sometimes you gotta weigh the positives and negatives, and in this case, I think the positives (low cost, ease of installation, low probability of problems) out weighs the negatives (chance of having it rupture, chance of having to dig it up)

Charles
 
C

Charles (in GA)

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VWandDodge said:
Unfortunately, this forum is rife with rocket surgeons who are convinced PVC can or should be used in compressed air systems. I would be the first to laugh when the pipe shattered and sends damaging shrapnel everywhere.
Click to expand...

I am not a "rocket surgeon" as you suggest, and do not recommended PVC for use in compressed air systems, and would not now, except for one simple thing you overlooked ITS GOING TO BE UNDERGROUND.

Charles
 
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V

VWandDodge

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Charles (in GA) said:
Normally, I never recommend PVC, it is not safe for use for compressed gasses due to the physical characteristics of the PVC when it ruptures, but this is underground.............. what happens should it rupture? hmmm.... "compressor seems to run alot when I turn the air valve on"

The issue with PVC is it is not damage tolerant under pressure. It explodes, scatters shrapnel everywhere, usually when impacted, sometimes on its own. also, PVC is not ultraviolet resistant, and sunlight over time damages exposed PVC................ but, its underground, it won't spread shards of plastic, its not likely to get impacted or damaged, and its not exposed to sunlight.

In a few years, the OP might have it rupture, and might have to dig it up, if he still lives there...............

Sometimes you gotta weigh the positives and negatives, and in this case, I think the positives (low cost, ease of installation, low probability of problems) out weighs the negatives (chance of having it rupture, chance of having to dig it up)

Charles
Click to expand...

Wow, are you ever chock full of BAD ADVICE. You admit that PVC should not be used for compressed gas yet recommend that it's "OK since it will be buried".

PVC pipe and compressed air is a topic that the hard-headed refuse to accept. Sorry, but it will not "make the compressor run a lot".

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

STATE OF WASHINGTON
Department of
Labor & Industries
Hazard Alert


For more information, call: 1-800-423-7233

FOR IMMEDIATE RELEASE May 26, 1988


PVC pipe not to be used in compressed air systems

OLYMPIA -- The Department of Labor and Industries warned today that plastic polyvinyl chloride (PVC) pipe cannot be used in compressed air piping systems without the risk of explosion.

When PVC piping explodes, plastic shrapnel pieces are thrown in all directions.

"We're seeing more incidents of explosive failure, and we're citing more employers for using PVC air system piping," said Paul Merrill, senior safety inspector in L&I's Spokane office.

"It's probably just a matter of time before someone gets seriously injured in one of these explosions unless everyone pays more attention to the manufacturer's warnings," Merrill said.

Last year, a section of PVC pipe being used for compressed air exploded 27 feet above a warehouse floor. A fragment of the pipe flew 60 feet and embedded itself in a roll of paper. Fortunately, nobody was in the area at the time.

A PVC pipe explosion in a new plant in Selah broke an employee's nose and cut his face.

PVC piping buried 3 feet underground at a Yakima manufacturing plant exploded, opening up a crater approximately 4 feet deep by 3 feet across.

Only one type of plastic pipe has been approved for use with compressed air. That pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for compressed air supply.

By law, employers must protect their workers by avoiding the use of unapproved PVC pipe in such systems. Existing compressed air systems which use PVC piping must be completely enclosed, buried or adequately guarded according to specifications approved by a professional consulting engineer.

NOTICE TO EMPLOYERS: If you have questions about the suitability of a material for air system piping, call Labor and Industries at the number listed above for a free consultation.

NOTICE TO EMPLOYEES: If you suspect that a pressurized PVC piping hazard exists, bring it to the attention of your employer. If you do not obtain satisfactory results, you may file a confidential complaint with the Department of Labor and Industries. Complaints are investigated promptly.
Click to expand...


http://www.lni.wa.gov/Safety/Basics/HazAlerts/902.asp

http://www.charlottepipe.com/Default.aspx?Page=PVC80&type=PVCCPVC
WARNING! Never test with or transport/store compressed air or gas in PVC pipe or fittings.
Click to expand...
 
P

PontiacFan

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Apr 25, 2007
Messages
102
In some industrial/commerical applications, they will run larger PVC thru the concrete or underground sections, & then run hose, electrical wiring, or other pipe in the middle of it.
That way, if they ever have issues, you can /pull/replace it.
The PVC is simply used an an 'alleyway'.
For instance, maybe use 2" PVC as a liner, then simply run a 1/2" hose thru there.
Or you could use black pipe inside the PVC also, if you can access any corners with pipe fittings such as an elbow, etc.
Unless of course you're going to have elbows at both ends, ..., in which bending black pipe around those corners to insert it would be impossible!


VWandDodge said:
Sorry, but it will not "make the compressor run a lot
Click to expand...
I think what he meant was, ..., if the PVC cracked or broke underground, & he didn't realize it, ..., it could bleed off compressed air quite a bit, & make the compressor run quite often to try to keep up with the leakage rate.".


Man, that PVC/CompressedAir battle never goes away around here, ...
 
V

VWandDodge

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Messages
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PontiacFan said:
I think what he meant was, ..., if the PVC cracked or broke underground, & he didn't realize it, ..., it could bleed off compressed air quite a bit, & make the compressor run quite often to try to keep up with the leakage rate.".


Man, that PVC/CompressedAir battle never goes away around here, ...
Click to expand...

Read the links I posted. They sum up the dangers quite well.

PVC pipe is not approved nor suitable for compressed gas delivery. The reason the battle never goes away is because some people refuse to understand nor acknowledge the dangers and think they know better.
 
C

c_mccann

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Mar 30, 2010
Messages
919
Rapid Air. What's your time worth to hook up all that black pipe and liners for PVC?? I was 5 hours on black pipe on my old system plus the $100 in pipe and fitings. If I billed myself at $30 per hour, that is a $250 system easily. Rapid Air is so much easire, flexible and the outlets have drains. No affiliation, just pragmatic.
 
B

Bull

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People who can't disagree with someone without being hostile, aggressive, rude etc. are wearing me thin.

Here is how I see some of the replies in this thread: "Hey man, your advice *****."

Here is how I would like to see those same replies: "Hey man, no offense intended, but I think your advice is poor/misguided/potentially dangerous. Let me explain why in a reasonable manner, devoid of superior airs."

I'll have the other mods look at this to get their opinion on whether my expectations are unreasonable.
 
W

wrenchr

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Bull said:
People who can't disagree with someone without being hostile, aggressive, rude etc. are wearing me thin.

Here is how I see some of the replies in this thread: "Hey man, your advice *****."

Here is how I would like to see those same replies: "Hey man, no offense intended, but I think your advice is poor/misguided/potentially dangerous. Let me explain why in a reasonable manner, devoid of superior airs."

I'll have the other mods look at this to get their opinion on whether my expectations are unreasonable.
Click to expand...

I agree 100%!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
J

Jack Olsen

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I agree. My suggestion would be that users here should offer their input in the same way they'd expect someone to offer it to them if they started a post with a question (or even an incorrect position on something).

No one needs to compromise their principles or their good sense in order to be polite.
 
A

A_Pmech

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Bull said:
I'll have the other mods look at this to get their opinion on whether my expectations are unreasonable.
Click to expand...

Your expectations are not unreasonable.

Further, OSHA's position on PVC piping is clear, it is prohibited for compressed gas use. After reading OSHA's position letter below there really is nothing left to argue:

OSHA said:
February 14, 1989

Mr. Jack Cannova Tempe
Industrial
412 W. Dryon Street
Tempe, Arizona 85283

Dear Mr. Cannova:

In response to your recent inquiry concerning our regulatory position on the use of plastic pipe for compressed air systems, I trust this letter will clear up any confusion over the issue.

It is our position that PVC pipe shall not be used as a means of transporting compressed air. This position follows the manufacturer's own statements that PVC is unsuitable for compressed air systems. We do allow the use of certain ABS materials that are specifically designed for compressed air systems. One such product is "Duraplus" air line piping system ABS pipe. However, as in any such system, the manufacturer's specifications on acceptable pressure and temperature considerations must be followed.

In closing, misapplication of a product, such as using PVC for compressed air systems, may result in citations and penalties being issued dependent upon the specific conditions.

I appreciate your concern and inquiry into this potential safety hazard.

Sincerely,

SAM A. ROGERS
Bureau Chief
Click to expand...

From this link:

http://www.osha.gov/dts/hib/hib_data/hib19880520.html
 
M

metal1313

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i would use galvanized pipe, or 3/4 to 1inch pex just for the underground run. galvanized isnt too expensive, and is easy to work with if you've done it before
 
M

MrMark

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You could use the black iron pipe that is factory coated with PVC for your air system. That is what I would probably do. That pipe gets wrapped with 40 mil PVC tape whereever nicked by a pipe wrench and at all fittings. It will rust out but much slower than galvanized or plain black pipe. That is the system used for Code Approved runs of gas piping in those jurisdictions that don't require polyethelene gas pipe.
 
F

Falcon67

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I would not use regular black iron as it will corrode. I would use at least galvanized and put a particle trap at the end in case you had some coating flaking later.

Here is a simple reason to use something other than PVC for air underground. I knew exactly where the lines were - well, I thought so. I found them with a pick. If they were at 130 PSI with air vs 50 PSI with water...not so good outcome IMHO.

WaterLine.jpg
 
G

Greatbear

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Somewhere, somebody had to have backfed a generator through a dryer plug in order to run their air compressor that was plumbed with PVC pipe inside a shop with OSB interior walls in order to run a plasma cutter to... :lol:
 
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