Air Lines, Food for thought!

Da Bull · Aug 26, 2006

I can’t remember in what magazine I saw it in recently, but they showed air lines plumbed with copper down legs and connect with rubber hose. What do you guys think about this setup? I work in the paper industry and we use Goodyear rubber hoses for compressed air needs. These hoses are pressurized for weeks at a time, at high pressure and volume, and with 26 years on the job I have never seen one fail! :beer:

wilbilt · Aug 26, 2006

I worked in commercial shops, and saw many setups using always-pressurized hose. Usually, it was the connection between the compressor(s) and the hard lines in the shop. This provided a cushion between the compressor vibrations and the solid piping (either galvanized iron pipe or copper).

I don't think I ever saw one of those hoses fail, although they were built from "normal" air hose a size or two larger than the shop air plumbing.

I have witnessesed hose failure at the bay on many occasions, though. This was usually at the reel, and a few times injuries resulted from the flailing hose end.

I would surmise that hoses in a stationary state would be far less likely to fail than those subjected to "end user" stresses.

Da Bull · Aug 26, 2006

I have seen hoses fail at the reel connection too, and at the shut offs. I was referring to the hose itself; I have never seen one rupture while in use or in the reel.I have been hit many times by a whipping hose when I dropped it on the floor and the valve turned on. We are always telling people not to use pvc pipe because its failure rate and the damage pvc shrapnel can cause. I thought this could be avoided with rubber hose! The hose we use is rated at 300 psi. So I thought it can handled any compressor we have in our garages. :beer:

REFLEXX · Aug 27, 2006

If I recall correctly, there are issues with condensation, or lack of with rubber hoses. I'm not sure what it was. Anyone???

wantedabiggergarage · Aug 27, 2006

First, I think the magazine your talking about was Family Handyman. I believe they had a garage/shop organization cover this month.

They showed a pancake style (read SMALL) compressor, sitting on a shelf, on the wall (away from little hands), with rubber going around the ceiling (and obstacles, reason they used rubber) then going to copper drops. There was a filter at the compressor, and drip legs at the drops (over the benchs). This kinda setup should be fine for Nailers, and air ratchets/impact guns, but do to the condensing of moisture (reason for multiple dryers) you WOULDN'T want to use this for a paint setup. The paint setups, always recommend the MINIMUM number of feet required to walk around and spray your project.
I have a pancake compressor for my nailers, and am really considering this for my basement shop.

boiler7904 · Aug 28, 2006

wantedabiggergarage said:
First, I think the magazine your talking about was Family Handyman. I believe they had a garage/shop organization cover this month.

They showed a pancake style (read SMALL) compressor, sitting on a shelf, on the wall (away from little hands), with rubber going around the ceiling (and obstacles, reason they used rubber) then going to copper drops. There was a filter at the compressor, and drip legs at the drops (over the benchs). This kinda setup should be fine for Nailers, and air ratchets/impact guns, but do to the condensing of moisture (reason for multiple dryers) you WOULDN'T want to use this for a paint setup. The paint setups, always recommend the MINIMUM number of feet required to walk around and spray your project.
I have a pancake compressor for my nailers, and am really considering this for my basement shop.

I think the article the original poster is referring to is in the Sept '06 issue of American Woodworker. Everything else you listed is accurate though.

Aahz · Aug 28, 2006

I hope I can make this sound right....I have had many customers ask me about the same type of setup...and I have seen some in auto shops around the country...If I understand correctly, you are asking if it's all right to use a hose for a header pipe and use copper for the drops....My reply to customers is usually the following: It depends...
A.) What size compressor are you running and how far do you need to go? Reasoning is pressure loss...the interior of a rubber hose isn't as smooth as pipe, copper, etc. and you will get quite a bit of pressure drop.
B.) Length of run ....Hose is expensive....a normal header for a 5 hp compressor should be about 1". The large pipe size also acts as added storage, so your compressor doesn't work as hard...If you pipe the header with a 3/8 or 1/2" hose, you aren't doing yourself any favors.

Aahz....www.standardus.com

Jeepguy · Aug 29, 2006

dido for aahz,

compressor size has a lot to do with it. if you are running a 5 hp @90 pounds and only use it to fill up tires go ahead. But hose causes friction and friction reduces flow and then your comp is working harder to keep up your 90 pounds and a laundry list of side-effects after that. rigid pipe is the way to go. Now i am partial to Trans-air (Garage-Pak) because i sell it but any rigid pipe, with the appropriate filtration is better than hoses. Getting smacked in the face with a run-away-hose @ 120 psi doesnt tickle. Use rigid

xsponge · Oct 2, 2006

High pressure CPVC is a nice alternative and easy to work with.

Stuart in MN · Oct 2, 2006

xsponge said:
High pressure CPVC is a nice alternative and easy to work with.

Uh oh....

Do a search here for information on using PVC pipe for air lines and you'll find many discussions. PVC is pressure rated for noncompressible fluids, but notfor compressed gases.

wantedabiggergarage · Oct 3, 2006

xsponge said:
High pressure CPVC is a nice alternative and easy to work with.

Are you sure your not thinking of gas rated ABS?
CPVC isn't rated for air, just liquids, and violates OSHA, so they can fine you.

boiler7904 · Oct 3, 2006

wantedabiggergarage said:
CPVC isn't rated for air, just liquids, and violates OSHA, so they can fine you.

As far as I know, OSHA can't inspect a private garage unless it is being used for business purposes. On the other hand, the local building department can inspect (and reject) any material that doesn't meet code as they see fit if you are installing it as part of a permitted and inspected project.

xsponge · Oct 3, 2006

Yes, I was referring to the Gas rated CPVC. Yet in a private garage, in which pressures neer go over 125 psi, 250 psi rated (for plumbing) CPVC would work.

wantedabiggergarage · Oct 4, 2006

xsponge said:
Yes, I was referring to the Gas rated CPVC. Yet in a private garage, in which pressures neer go over 125 psi, 250 psi rated (for plumbing) CPVC would work.

Link?

Never EVER seen gas rated cpvc. Seen several brands of ABS.

DocsMachine · Oct 4, 2006

xsponge said:
Yes, I was referring to the Gas rated CPVC. Yet in a private garage, in which pressures neer go over 125 psi, 250 psi rated (for plumbing) CPVC would work.

-The problem with PVC isn't the working pressure, it's the cycling (flex as the pressure varies during use) and the pressure spiking (a 120-psi working pressure system can see a spike of 200+ for an instant, as the tool/draw is shut off- moving air has momentum.)

As the plastic cycles/flexes, it fatigues- eventually that 250 psi working pressure becomes a 225 psi working pressure, and then eventually a 185 psi working pressure...

Worse, if/when PVC fails, it shatters. Copper and steel rupture, but typically don't spray any pieces. PVC creates shrapnel when it goes.

If you plan on working in your shop for any length of time (IE, you're not planning on moving within a few years) then it's worth the relatively small extra cost to go with copper. It's easier to install and modify than steel, doesn't rust, and is far less likely to fail in a shop environment.

Doc.

larry4406 · Oct 5, 2006

My company uses cpvc for water piping in the houses we build. When the system is tested, it must be tested using water as the building codes specifically prohibit air tests on the cpvc water supply piping. Copper systems can be tested using either air or water. food for thought.

Royalblu · Oct 5, 2006

I am in the process right now of plumbing my shop for air. I have a 30'x40' metal building. I have a modest 5HP Devillbis compressor running on 220V. I am going the rubber hose route like what was in the American Woodworker magazine. I was able to acquire at a very reasonable price several lengths of the hose from the owner of the building I have my office in now. It is mostly all 1/2". I mainly use air for nailers and dust off. I do not paint or use many air tools. I think the system will work pretty well for me. I am planning to make a complete loop around the top of the shop with the thinking that may help my CFM issue.
I am even using the rubber hose for the drop downs as it is still much cheaper than copper. Have you priced copper lately? I paid almost $7 for a 4' piece last night. Lowes is even more expensive than my local Farm and Home on the copper stuff.
Regards,
James

ZRX61 · Oct 5, 2006

Use black iron pipe, PVC hurts like a mofo when it lets go..

enginerd · Oct 7, 2006

Anyone used Garagepak systems? Thats the route we're thinking about.

JohnZ · Oct 7, 2006

In car assembly plants (120 psi shop air, regulated to 90 psi at the FRL's), we run coiled flex hose from the iron overhead header to the FRL trolleys, and rubber hose down from the FRL trolleys to the air tools, usually holstered at the bottom of a bar attached to the trolley. Have been doing this for 50 years, hardly ever see one fail, and both the hose and trolley get moved 65 times per hour, 16 hours a day. :thumbup:

wilbilt · Oct 7, 2006

JohnZ said:
In car assembly plants (120 psi shop air, regulated to 90 psi at the FRL's), we run coiled flex hose from the iron overhead header to the FRL trolleys, and rubber hose down from the FRL trolleys to the air tools, usually holstered at the bottom of a bar attached to the trolley. Have been doing this for 50 years, hardly ever see one fail, and both the hose and trolley get moved 65 times per hour, 16 hours a day.

I have worked in shops with coiled hoses from the header to the tools. They were a pain, and always getting caught on bumpers and lift posts. Of course, there were no trolleys or holsters. That sounds like an excellent idea.

It seems you have some experience in a production environment....

wantedabiggergarage · Oct 8, 2006

xsponge said:
Yes, I was referring to the Gas rated CPVC. Yet in a private garage, in which pressures neer go over 125 psi, 250 psi rated (for plumbing) CPVC would work.

Bump

Still waiting for a link/brand name!

Egan · Oct 8, 2006

wantedabiggergarage said:
Bump

Still waiting for a link/brand name!

Air rated ABS:

Duraplus http://www.ipexinc.com/Content/EN_CA/2_0_Products/2_1_Industrial/2_1_4_1_Duraplus.asp

Flexible air Line:

Duratec http://www.ipexinc.com/Content/EN_CA/2_0_Products/2_1_Industrial/2_1_4_2_Duratec.asp

Air rated ABS:

Chemaire https://www.tolco.com/assets/ChmairOvrw.pdf#search="chemaire"

Stuart in MN · Oct 8, 2006

The ford-trucks.com forum has a discussion devoted to why PVC pipe is not appropriate for compressed air lines: Link to ford-trucks.com air line page

There are many other similar pages on the web, this is just one that's easy to find.

Charles (in GA) · Oct 8, 2006

wantedabiggergarage said:
Bump

Still waiting for a link/brand name!

Here is a link to the Chemaire manufacturers web page.

http://www.nibco.com/cms.do?id=2&pId=14

Here is the link to the Chemaire product guide and technical manual.

http://www.nibco.com/assets/ChmairTech.pdf

Chemaire is a viable system for a simple or small installation. The pipe can be glued with the proper glue, or using another type of fitting that Chemaire has, it simply slips together and locks, using o-rings for seals. Pricey, but now copper is also, and the chemaire is easier to work with.

Charles

Rrumbler · Oct 8, 2006

A couple of rhetorical questions:

What price are you willing to put on the safety and well being of yourself and others??

Is the value of ease of installation greater than that of durability and safety??

chaingang · Oct 8, 2006

Hey guys,
When you discuss copper air lines are we talking about sweat fit as in like plumbing? As a maint. mgr. in a manufactuing facility I am very familiar with black iron as it is all we use. Never thought about copper for air in a shop, but as I get ready to build mine it sounds interesting. I bet it looks cool finished off against painted walls and such. Anyone got pics of their system finished?

Abe · Oct 8, 2006

Thinking on copper for a second. Wouldn't the better heat transfer ability (versus iron or plastic) of copper help condense out moisture? Thus, making the drop drains more effective?

Please anyone correct me if I'm wrong.
Abe

Charles (in GA) · Oct 8, 2006

Rrumbler said:
A couple of rhetorical questions:

What price are you willing to put on the safety and well being of yourself and others??

Is the value of ease of installation greater than that of durability and safety??

Not sure, but if you are referring to my comments in my post #25, immediately preceding yours, consider reading the Chemaire manual. This is an ABS based pipe specifically designed by Nibco for use on compressed air systems. It is approved by the California OSHA for such use, and is accepted also by the US OSHA for use in compressed air systems. It is a type of pipe that, when it fails due to age, damage, overpressure, etc, it splits, much in the same way a metal pipe does when it fails, and it does not shatter into splinters and sharpnel. From reading the technical information published by Nibco, I would not hesitate to use it in a compressed air system, either at my home or in a commercial enviroment, which is what it was designed for.

Charles

Charles (in GA) · Oct 8, 2006

chaingang said:
Hey guys,
When you discuss copper air lines are we talking about sweat fit as in like plumbing? As a maint. mgr. in a manufactuing facility I am very familiar with black iron as it is all we use. Never thought about copper for air in a shop, but as I get ready to build mine it sounds interesting. I bet it looks cool finished off against painted walls and such. Anyone got pics of their system finished?

Absolutely!!! If you look at the Copper Tube Handbook, published by the Copper Devolopment Association, it list the industry specs for all type of copper tubing and the strength of soldered fittings using different types of solder.

Warning: this is a 6.38 meg download, you really need broadband to download this, or lots of time and a good connection.

http://www.copper.org/resources/pub_list/pdf/copper_tube_handbook.pdf

Even worst case, one inch type L has a rated internal working pressure of about 400 PSI at 200 degrees F, and one inch Type M has a rated int, work press of 275 PSI also at 200 deg F. This is for annealed one inch. Go to smaller sizes or drawn copper, not annealed, and the pressures go up from there. Types L and M are the two common typed of rigid copper tubing you see on the racks at the big box stores and are what is normally used in water systems. The actual burst pressure of one inch type L is 5115 psi (drawn) and 2650 psi (annealed) and for type M one inch it is 3865 (drawn, annealed not manufactured). Smaller pipes have higher ratings.

The solder joints are rated on up to one inch pipe, using 95-5 solder (tin-antimony) at 200 degrees F as 505 psi. You CANNOT use 50/50 lead-tin as the joint is only rated at 100 psi (also at 200 F) At lower temps the joints are rated even higher.

Pics, here is the link to one thread on this board with lots of large pics of a copper air system, dialup beware as the author states.

http://www.garagejournal.com/forum/showthread.php?t=2003&highlight=copper+pipe

Charles

PAToyota · Oct 8, 2006

One issue with only using the rubber (vinyl, what have you) hoses is that a metal line will condense more water vapor out of the compressed air.

Rrumbler · Oct 9, 2006

Charles, those questions were just fodder for pondering; I wasn't refering to anything in particular, rather the general scope of this discussion. I think it's mainly about choices.

As to the systems you posted the links to: yes, I did check them out, and they seem well engineered, adequately tested, and approved for industrial use. However, they are likely as, or more, costly than even the copper system would be.

For myself, when and if I get to setting up my system in a proper fashion, I'll use black pipe; I have the tools, skills, and time to do so.

wantedabiggergarage · Oct 9, 2006

wantedabiggergarage said:
Bump

Still waiting for a link/brand name!

Guys, you didn't read what I quoted, did you?
He stated, he used a LEGALLY allowed cpvc. I have NEVER seen such a thing (seen ABS, copper, black iron, hose, and even an air rated pex), so I ask again, for a link, to back up his statements!

From what I had read of the copper handbook (this was 4 or 5 years ago), they said to braze the copper, NOT SWEAT! Sweating was different material and burst pressures, unfortunatly, people still tend to use the terms interchangably.

Charles (in GA) · Oct 9, 2006

Rrumbler said:
As to the systems you posted the links to: yes, I did check them out, and they seem well engineered, adequately tested, and approved for industrial use. However, they are likely as, or more, costly than even the copper system would be.

As the price of copper rises, the Chemair system becomes more and more attractive. I should have done the air system a year ago, but never seem to want to spend the money or time. I will have to weigh both again.

Charles

Charles (in GA) · Oct 9, 2006

Guys, you didn't read what I quoted, did you?
He stated, he used a LEGALLY allowed cpvc. I have NEVER seen such a thing (seen ABS, copper, black iron, hose, and even an air rated pex), so I ask again, for a link, to back up his statements!

I saw what you asked, I too am waiting, but we'll never see that link.

From what I had read of the copper handbook (this was 4 or 5 years ago), they said to braze the copper, NOT SWEAT! Sweating was different material and burst pressures, unfortunatly, people still tend to use the terms interchangably.

The copper handbook................

http://www.copper.org/resources/pub_list/pdf/copper_tube_handbook.pdf

says a properly done 95-5 soldered (thats sweating) joint is good for 500+ psi at 200 degrees F, more at lower temps. No need to braze. certain other types of solders (E and HB) are strong enough, but not as strong as 95-5. The only one that would not work is 50-50, just too weak. (ref. Table 4, page 28)

Quoting from the handbook (p 43).................

"The 50-50 tin-lead solder is
suitable for moderate pressures and
temperatures. For higher pressures, or
where greater joint strength is required,
95-5 tin-antimony solder and alloys E
and HB can be used. For continuous
operation at temperatures exceeding
250°F, or where the highest joint
strength is required, brazing filler
metals should be used"

Charles

Royalblu · Oct 12, 2006

I am not sure how most auto drains work on some compressors but here is what I did.
I removed the petcock valve from the bottom of my compressor and installed a brass elbow. Added a 4-5" length of tube to that and then put an electric solenoid valve on the end of that. My thinking there is that the brass elbow and tube create bit of a resevoir for any water that is going to accumulate there and that keeps the bottom of the tank from rusting. The brass does not rust anyway. The electric solenoid valve was bought surplus and is connected to a lamp timer that turns it on for one minute once a day. The output of the valve is dumped out on the ground.
Best Regards,
James

PAToyota · Oct 12, 2006

I found something like this used: http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=4533279&PMT4NO=12859348

I wouldn't pay the new price for one, though. I do like the "homebrew" idea of the solenoid valve and lamp timer, though. Even buying the parts new you'd likely spend much less than buying the "commercial" version above.

sandtrap · Oct 14, 2006

I used 1/2"pvc in mine about 10 years ago and it's still going strong at 125 psi.

Oilcan Harry · Oct 25, 2006

I worked in a small machine shop that had 3/4" PVC air lines. One day a boom shook the building. The PVC had exploded and stuck shrapnel in the opposte wall 25 feet away! [Right where I was grinding valve seats 20 minutes earlier.]The shrapnel impact knocked things off the wall in the rental unit next door. No injuries, fortunately we were all eating lunch in the office when it let go. I don't trust it.

DIGGER_DAVE · Oct 25, 2006

Rrumbler said:
For myself, when and if I get to setting up my system in a proper fashion, I'll use black pipe; I have the tools, skills, and time to do so.

Some MORE food for thought.

Many large shops use BLACK IRON pipe (some even is galvanized) probably because it's economical. (for large quanities) Then add the fact that cutting and threading pieces is easier and faster.

It withstands the odd "bump" without damage.

All that said; Black Iron pipe RUSTS INSIDE over time. (and it doesn't matter how DRY the air is; there is ALWAYS some moisture - it's the nature of the compression process)

I dismantled an air system (pipeing) that was carrying so called "DRY AIR" that had been in service for about 12 years. Over HALF the pipe was filled with rust! (this system was drained regularly at the compressor and all the "down leg/drops")

Those who claim that, "Oh, I did/will use/used galvanized pipe." Need to consider every time a galvanized pipe is cut; you have just EXPOSED the raw pipe on the end. THAT joint will rust over time!

Even with the rising cost of copper; I just recently re-piped my shop with it.
Where any drops come down the wall; and are potentially in harms way, I slid the copper drops INSIDE Black Iron pipe and clamped them to the wall.
(the Black Iron pipe is purely for protection; it doesn't carry air.)

Air Lines, Food for thought!

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