PEX is only good for 80 psi at 200 F (the discharge temperature of the compressor). ABS or even cross linked polyethylene (PEX) can make acceptable air piping, but I'd look for a manufacturer who as done the design and sells the plastic tubing as suitable for compressed air....carguy123 said:
Pvc Pipe Or Copper For Air Line?
- Thread starter toolman
- Start date
80 psi vs. 160 is quite a difference.
Hmmmmm, how about a section of black pipe connecting from the compressor (outside) to the plumbing (inside) and by then the temp should be quite a bit lower.
MyDomain let us know how the PEX takes it. Pex should swell vs. burst w/shrapnel. Any bursting should be non violent (but scary)
Double Hmmmmm.
Swelling means that you couldn't use a rigid attachment system.
Hmmmmm, how about a section of black pipe connecting from the compressor (outside) to the plumbing (inside) and by then the temp should be quite a bit lower.
MyDomain let us know how the PEX takes it. Pex should swell vs. burst w/shrapnel. Any bursting should be non violent (but scary)
Double Hmmmmm.
Swelling means that you couldn't use a rigid attachment system.
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MyDomain
Well-known member
Here is an alternative we may agree on. It is called Pex-al-Pex. It is relatively inexpensive yet handles higher pressure according to this web site.
http://www.jupiterheating.com/help/kitec-xpa-pipe.html
http://www.hvacgiant.com/dept/heati...adwords!7555&keyword=*pex+al+pex*&match_type=
http://www.plasticpipe.org/applications/productinfo03_5_1.php
I am foregoing the standard Pex test after reading about this type. It is approved for compressed air and resistant to chemicals.
http://www.jupiterheating.com/help/kitec-xpa-pipe.html
http://www.hvacgiant.com/dept/heati...adwords!7555&keyword=*pex+al+pex*&match_type=
http://www.plasticpipe.org/applications/productinfo03_5_1.php
I am foregoing the standard Pex test after reading about this type. It is approved for compressed air and resistant to chemicals.
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If this is what I think it is then the aluminum is really only about alum foil thickness.
It does hold the pipe's shape longer but freezing of water in the pipe or too high an air pressure ruptures the alum and you are back with plain old Pex
It does hold the pipe's shape longer but freezing of water in the pipe or too high an air pressure ruptures the alum and you are back with plain old Pex
PAToyota
Well-known member
carguy123 said:
Ummm... Because of the specifications of my compressor...
SPECIFICATIONS: 5 HP, 2-stage, 28 amps/230 volts, 1-phase, maximum pressure is 175 psi. Cylinders: (2) 4'' and 2-1/4'' bore x 3'' stroke, 80 gal vertical tank, 942 pump rpm, 21.8 piston displacement, 17.7 cfm @ 100 psi, 17.2 cfm @ 175 psi. Compressor is complete with magnetic starter, 2 qts. oil, rubber mounting pads and outlet valve. 72'' high, 39'' wide, 24'' deep. Made in USA.
So . . . that is you MAXIMUM pressure not a pressure you'd normally operate equipment at.
Usually you will set your system at a much lower air pressure or else it means you have to have an adjustment valve on every piece of equipment or ever drop spot which could get very expensive.
Usually you will set your system at a much lower air pressure or else it means you have to have an adjustment valve on every piece of equipment or ever drop spot which could get very expensive.
mikeyr
Well-known member
True, but all the lines in my shop are at 175psi, I certainly was not about to walk outside and around the corner each time I needed to change air pressure. ALL drops in my garage have a regulator so I only have to walk to the wall and change pressure. That means all the pipes in the shop are above that 160psi limit.carguy123 said:
mikeyr
Well-known member
Look at this way guys, how much are you going to save when you plumb your shop in pvc ? how long are you going to live in that shop ? divide the savings by the number years and you decide if pvc shrapnel in your head or your kids head or your wifes head is worth that savings.
That pex pipe I am sure is more expensive than pvc, maybe less than copper but it is worth the savings ? come on ! this is a shop that you supposedly enjoy being in and working in, make it right the first time. Don't go making it right after you drive your wife/kid to the hospital or they drive you there, just to save a few bucks. I did mine with copper and a regulator at each drop, spent some money but that was 8 or 9 years ago, I have long forgotten how much I spent and I am still enjoy the setup.
That pex pipe I am sure is more expensive than pvc, maybe less than copper but it is worth the savings ? come on ! this is a shop that you supposedly enjoy being in and working in, make it right the first time. Don't go making it right after you drive your wife/kid to the hospital or they drive you there, just to save a few bucks. I did mine with copper and a regulator at each drop, spent some money but that was 8 or 9 years ago, I have long forgotten how much I spent and I am still enjoy the setup.
Uncle Buck
Banned
Regardless of temperatures pressures etc. there is a reason that most plastic pipe, regardless of what schedule is not listed as suitable for use in compressed air systems, that reason is.. The manufacturer knows that the grade of plastic pipe in question is not suitable for the application. There is some kind of plastic pipe out there that is suitable, I do not know the grade, type, schedule or whatever, all I do know is that on the side of the pipe it states that the pipe is suitable for use in compressed air systems. If your pipe does not say that on the side, you do not have the correct plastic pipe for the application. Why is that so difficult? 
Hammerdown
Well-known member
I saw this modular piping system in a showroom and it looked very cool. It installs with compression fittings (No brazing or soldering required) and is made of aluminum. I am considering this system to replace the hoses for my (Eventual) GarageMahal. It is worth a look- www.bluepipeguys.com
Charles (in GA)
Well-known member
milo said:
The bigger the better. The smaller a hose or pipe, the more restrictive, and more friction you have. less flow.
I think it sounds like most people use 3/4 for a main line around a shop and 1/2 for drops. If you really need volume you might want one inch for the main line.
Charles
ron in sc
Well-known member
My last drop in the new garage may be as far away from the compressor as 125' to 150' so I was planning on using 1" pipe for the first 25', which is a straight run and then 3/4 for the rest.
Might I be able to get away with just 3/4" for everything.
It's a 175 psi compressor.
Might I be able to get away with just 3/4" for everything.
It's a 175 psi compressor.
If your looking to plastic pipe for the long lengths and flexibility there are alternatives that are approved for this use. We install nylon tubing in industrial plants on a regular basis. Its especially useful in situations where you need to feed an air cylinder on a moving part. I have never seen this tubing fail or get brittle even on machines cycling at over 400 per minute.
We use type11 Nylon (mcmaster #5548K78). In a 1/2"OD, 3/8" ID it goes for about $0.79/foot in 100' rolls. 1/4" is much more flexible and will run most air tools. The best part is the instant fittings. You could probably pipe your shop in an afternoon using this system.
If I were doing a home shop, using this method, I would probably run a trunk line using black pipe and use nylon tubing for the branch lines. Then copper stubs to quick connect fittings.
We use type11 Nylon (mcmaster #5548K78). In a 1/2"OD, 3/8" ID it goes for about $0.79/foot in 100' rolls. 1/4" is much more flexible and will run most air tools. The best part is the instant fittings. You could probably pipe your shop in an afternoon using this system.
If I were doing a home shop, using this method, I would probably run a trunk line using black pipe and use nylon tubing for the branch lines. Then copper stubs to quick connect fittings.
We are India Based manufacturers of the rigid aluminum pipe fittings which can be used for compressed air lines up to 13 bars. The fittings are quick fitting push in type making the installation easy and quick The fitting are modular in design meaning any modification can be done very quickly and without any hassle. The fittings are re usable dose not need any skilled person to do installations The products comes in complete range with manifolds, droplets, wall mounting brackets, clamps etc with sizes ranging from diameter 16 mm to diameter 63 mm For further information
Please contact customer care engineer Mr Vijay Pai at [email protected]
Please contact customer care engineer Mr Vijay Pai at [email protected]
toolman said:Last year I used pvc for my air compressor lines. After reading many dangers by using pvc I have decided to stop using those linesNow I’m thinking of using copper instead
Is this safe to use. If so is there any special way to install? Is there a certain kind of solder to use?
russlaferrera
Well-known member
Reading everyone's post, there is an overwhelming majority in favor of copper pipe, next is steel pipe, last is plastic. All have given their reasons why they use their product of choice.
Cost is a factor, as is safety, ease of installation. What is the ranking of your preference?
Copper= $.80 ft X 100 ft-- $80, fittings another $50, easy to install. Total cost $130. Will last a lifetime, very safe!
Plastic= $.12 ft X 100 ft-- $12, fittings another $10, easy to install. Total cost $22. MAY last a lifetime, depending on exposure to light, shock, age.
So the difference is $108, for peace of mind that you have a proper system that will be safe. That is recommended by the industry. That is risk free. Or is this a risk worth taking?
Should you check other web sites. ALL agree on this issue no plastic, (PVC). Question. What do 98 out of 100 people know that I don't?
Cost is a factor, as is safety, ease of installation. What is the ranking of your preference?
Copper= $.80 ft X 100 ft-- $80, fittings another $50, easy to install. Total cost $130. Will last a lifetime, very safe!
Plastic= $.12 ft X 100 ft-- $12, fittings another $10, easy to install. Total cost $22. MAY last a lifetime, depending on exposure to light, shock, age.
So the difference is $108, for peace of mind that you have a proper system that will be safe. That is recommended by the industry. That is risk free. Or is this a risk worth taking?
Should you check other web sites. ALL agree on this issue no plastic, (PVC). Question. What do 98 out of 100 people know that I don't?
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wantedabiggergarage
Member Emeritus
russlaferrera said:
What do they know? Gas pressure is rated different then water pressure. It is illegal to use pvc pipe (hence the OSHA fines). Plastic tends to shatter, metal ruptures.
MyDomain
Well-known member
My 20' of 3/4 Pex has passed the test for me. No expansion, bulging or excessive leakage around fittings (none with a bubble check). Our branch manager saw pressure testing at a factory of over 400 psi with no effect on the pipe...the fittings eventually blew apart first. UV light exposure will be next to none along the ceiling and walls of my garage so that is not a concern.
Price difference is huge, time savings now and in the future is huge. There is no safety concern since it is a flexible pipe. I think it will do just fine, personally. Not saying it is the right thing for everyone. If you have the time and money to use copper no doubt it will look impressive...especially polished!
I see no reason to disparage people for wanting to try something different. I believe the main reason 98 out of 100 choose copper is because that is what has always been used and most guys hate change.
BTW Russ, is that .80 per foot for 3/4 copper? I just checked the price locally and got a quote of 1.61 per foot for M, 2.27 a foot for L.
Wanted...I am speaking for a residential garage only.
Price difference is huge, time savings now and in the future is huge. There is no safety concern since it is a flexible pipe. I think it will do just fine, personally. Not saying it is the right thing for everyone. If you have the time and money to use copper no doubt it will look impressive...especially polished!
I see no reason to disparage people for wanting to try something different. I believe the main reason 98 out of 100 choose copper is because that is what has always been used and most guys hate change.
BTW Russ, is that .80 per foot for 3/4 copper? I just checked the price locally and got a quote of 1.61 per foot for M, 2.27 a foot for L.
Wanted...I am speaking for a residential garage only.
russlaferrera
Well-known member
I just bought 150 ft 3/4 aluminum pipe for $20. The pipe is new. The deals are out there. Scrap yards are a good place to look.
russlaferrera
Well-known member
[QUOTE=M I see no reason to disparage people for wanting to try something different. I believe the main reason 98 out of 100 choose copper is because that is what has always been used and most guys hate change.
Point taken....However WE would hate to see anyone be injuried needlessly. Another downside, Plastic does NOT show up in an Xray. I will say that this is my opinion based of fact I know to be true. My belief is everyone has the right to do what they wish to do. We ALL must be accountable for our actions, right or wrong. I am sure we have heard about the "other guy" What about "I" screwed up" That is not heard often!
I for one love working with plastic, but plastic has their place, Air lines, No.
The end of my rant! russ
Point taken....However WE would hate to see anyone be injuried needlessly. Another downside, Plastic does NOT show up in an Xray. I will say that this is my opinion based of fact I know to be true. My belief is everyone has the right to do what they wish to do. We ALL must be accountable for our actions, right or wrong. I am sure we have heard about the "other guy" What about "I" screwed up" That is not heard often!
I for one love working with plastic, but plastic has their place, Air lines, No.
The end of my rant! russ
PAToyota
Well-known member
On the "plastic" debate, there is PEX and then there is PVC.
I'd never use PVC due to the brittle nature discussed here ad nauseam... When it goes, it is going to go with shrapnel... End of story as far as I'm concerned.
PEX is another matter. When or if it goes is not necessarily the argument because like copper, it is going to split open and rupture and release pressure without the shrapnel.
Personally, I've used copper due to the track record and (again, personally) more confidence in the end product. But I'm not going to disparage anyone for using PEX because there isn't the chance for serious injury that PVC has.
I'd never use PVC due to the brittle nature discussed here ad nauseam... When it goes, it is going to go with shrapnel... End of story as far as I'm concerned.
PEX is another matter. When or if it goes is not necessarily the argument because like copper, it is going to split open and rupture and release pressure without the shrapnel.
Personally, I've used copper due to the track record and (again, personally) more confidence in the end product. But I'm not going to disparage anyone for using PEX because there isn't the chance for serious injury that PVC has.
prachait said:
Do you make the stuff for TransAir? I know someone who sells it and he says it is great stuff. But the fittings are quite expensive. here is the transair site,
http://www.transair.legris.com/en/index.htm
I just did copper myself.
Brew
I'm surprised no one has mentioned using industrial rubber hose such as those made by Goodyear. http://www.goodyearindustrialproduc...search.pl?application_ID=14&search_app_ID=Go! They have a wide variety of products, the installation is way faster than any other method with long runs that can turn corners or snake around obstacles. It's cheaper than copper and more impact resistant than iron. No rusting, high working pressures, fittings not cheap, but easy to use.
It was the easy choice when retrofitting my garage/shop/spray booth.
David
my first post- love this site!
It was the easy choice when retrofitting my garage/shop/spray booth.
David
my first post- love this site!
PAToyota
Well-known member
Only problem with rubber (and it is an issue with PEX as well) is that you won't condense the water vapor out of the air like you will with metal piping.
The moisture could be an issue for some. I have an 80 gallon tank which will naturally catch the vast majority compared to smaller tanks. It's plumbed to a condenser with its own drain. For my paint booth I have a moisture/oil filter and it rarely has any water to drain. The other drops have nothing since the air is so dry at that point. I also live in Denver where the air is generally very dry to begin with.
With regard to cooling air and condensing out entrained water, copper (or steel) is 100 times more conductive than any plastic. But this exaggerates the true picture in light of the total heat transfer path.
The compressed air must transfer its heat to the internal wall of the pipe, the pipe must conduct heat from the internal wall to the external wall, and the pipe must then radiate heat from the external wall to the ambient shop air. The air-to-pipe interfaces have much more resistance to heat flow than does the metal piping itself.
The net effect of this is (as I recall) that copper tube transfers about twice as much heat per unit length as does Pex or pex-al-pex. Not 100 times as much. So those contemplating plastic or nylon for air lines can compensate for the lost heat transfer by placing the first drop farther away from the compressor. But these distribution systems do not lose out on the benefits of cooling and condensing merely by dint of being plastic.
Note that the thermal conductivity of PVC hose, PVC pipe, or rubber air hose is much lower than PEX. The amount of tubing you'd need for meaningful cooling and condensing with those materials is quite long.
The compressed air must transfer its heat to the internal wall of the pipe, the pipe must conduct heat from the internal wall to the external wall, and the pipe must then radiate heat from the external wall to the ambient shop air. The air-to-pipe interfaces have much more resistance to heat flow than does the metal piping itself.
The net effect of this is (as I recall) that copper tube transfers about twice as much heat per unit length as does Pex or pex-al-pex. Not 100 times as much. So those contemplating plastic or nylon for air lines can compensate for the lost heat transfer by placing the first drop farther away from the compressor. But these distribution systems do not lose out on the benefits of cooling and condensing merely by dint of being plastic.
Note that the thermal conductivity of PVC hose, PVC pipe, or rubber air hose is much lower than PEX. The amount of tubing you'd need for meaningful cooling and condensing with those materials is quite long.
Okay, the pex is starting to sound like a pretty good idea to me. So where do you guys get the fittings that you need for doing air lines with pex? I imagine they are compression fittings? Or can you use the copper fittings with crimp rings like they do for water plumbing? The local Menard's has plenty of that stuff, but I'm sure I'll still need other fittings for air that they don't have available for water. I'd really like to do a complete cost comparison for myself, as I will be plumbing my shop for air this summer.
I'm sure copper would look much better, but if the cost difference is quite a bit, I might be able to overlook the "wavy" runs of pex. If it's around $100 or less (difference), I might just stick with copper. I'll have probably 120' or so of horizontal runs, with probably 4 or 5 drops of 8' or so. Thanks for any help guys!
I'm sure copper would look much better, but if the cost difference is quite a bit, I might be able to overlook the "wavy" runs of pex. If it's around $100 or less (difference), I might just stick with copper. I'll have probably 120' or so of horizontal runs, with probably 4 or 5 drops of 8' or so. Thanks for any help guys!
Your local professional's plumbing supply store will have everything you need. You can either stretch the tubing over barb fittings. The stretcher tool is about $200. Or you can use crimp rings and fittings. The crimper tool is about $150. I'm a certified PEX installer and have the tools. But, to buy them just for this job might tip the equation in favor of copper.BowtieNut said:
will02
Active member
When I did my floor pex tubing, I rented the crimp tool from my local Ace hardware store for 10 bucks for the day.Ironcrow said:
I did all my airlines in copper by the way.
Cadien
New member
I was wondering what how much could I actually get into a forum on garages and lo and behold The first thread I'm on tells me something I didn't know. Now, Do I really wanna go and remove a couple of hundred feet of black pipe and re-plumb with copper. Jeez. that'd get steep lemme tell ya.
TorqueWrench
Well-known member
Stirring the pot...
I see this on here all the time...Air pressure rating is different than water pressure rating...and I just have to ask how?
100psi of water is the same as 100psi or air, is it not? you know, kinda like 100# of feathers and 10# of bricks...
Please educate me.
For the record, I plumbed my house with PEX and plan to use it for airlines as well. I think the rating on the stuff in my house was 400psi @ 73 Deg.
I see this on here all the time...Air pressure rating is different than water pressure rating...and I just have to ask how?
100psi of water is the same as 100psi or air, is it not? you know, kinda like 100# of feathers and 10# of bricks...
Please educate me.
For the record, I plumbed my house with PEX and plan to use it for airlines as well. I think the rating on the stuff in my house was 400psi @ 73 Deg.
PAToyota
Well-known member
Re: Stirring the pot...
The whole issue of embodied energy - air compresses while liquids don't. That is what makes your hydraulic brake system work and why it does not work when it has air bubbles in it.
If you put a liquid under pressure so that it is 100 psi, it still has pretty much the same volume. Say a gallon of liquid at 0 psi is basically .99 of a gallon at 100 psi. But take a gallon of gas and compress it to 100 psi and you have a mere fraction of a gallon. So when that gas decompresses it also expands exponentially. This is why they pressure test vessels with water.
TorqueWrench said:
The whole issue of embodied energy - air compresses while liquids don't. That is what makes your hydraulic brake system work and why it does not work when it has air bubbles in it.
If you put a liquid under pressure so that it is 100 psi, it still has pretty much the same volume. Say a gallon of liquid at 0 psi is basically .99 of a gallon at 100 psi. But take a gallon of gas and compress it to 100 psi and you have a mere fraction of a gallon. So when that gas decompresses it also expands exponentially. This is why they pressure test vessels with water.
Here is my 2 cents. I installed a pvc air system in our commercial shop about 20 years ago. First I used a large 3/4" regulator bolted to the wall and connected to the compressor with a flexible line. The regulator stays set at 90psi and doesnt get changed. From there I ran 3/4" schd 40 thru out the shop across the top beams all around and clamped it about every four feet. Then for the drops I connected to that line with a tee and dropped it strainght down also clamping it to the wall for support. Then at the area where I would be connecting my hoses I made a manifold of sorts with galvinized pipe, ball valves, and my quick connect. One valve above the outlet to shutoff the air line and one about 12" below to blow out any moisture. I welded flat straps to the pipe with holes to bolt it to the wall. This put all the strain of working on the steel manifold bolted to the wall and the regulator keeps the line pressure at 90psi at all times. No problems and would do it again.
Charles (in GA)
Well-known member
gregs said:
Just hope a state or federal OSHA inspector never walks in your shop. You WILL get cited, and probably shut down till its replaced. OSHA does have policy letters out about this that clearly state that the PVC is unsafe and not allowed in an OSHA regulated workplace.
Just so as to not beat the "dead horse to death" as that has certainly been done here with the PVC and compressed air issue, I'll merely offer links to the OSHA information and leave it at that for you'all to read up on it.
http://www.osha.gov/dts/hib/hib_data/hib19880520.html
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=20202
http://www.occupationalhazards.com/News/Article/33587/OSHA_Fines_Ga_Company_Nearly_155000.aspx
http://list.uvm.edu/cgi-bin/wa?A2=ind9806B&L=SAFETY&D=0&T=0&P=3479
http://www.thefreelibrary.com/An+Accident+Waiting+to+Happen-a0136835982
http://www.doli.state.mn.us/pdf/2098sl.pdf
Charles
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