Copper Air Line Questions

[matt_i]

The only downside of black iron pipe is that if you decide to make a change, you generally get to saw into the pipe and fit it back up with a union.

Copper, you cut out a short section, install a tee, solder back up, and life goes on.

All other points have been made, black iron will beat up your nice drywall on a surface install unless cleaned and painted on the exterior and lots of care with the pipe wrenches. Likewise, copper has burning hot torches to cause the same effect.

I like JW Harris Sta Brite #8 solder and their StaClean flux. It is safe for potable water, lead free, and has at least twice the strength of the common big box "lead free plumbing solder" offerings.

There is some danger that if a fire broke out, the heat could melt the solder out of the copper lines, causing a burst. Whereas the steel pipe (not really pure iron, just a name that "stuck") will take so much more abuse, heat and otherwise.

One thing to note is that if you intend a 3/4" ID, you probably need to jump up to a 1" connector hose. Check out the ID of barbed fittings meant to connect NPT-M to hose ID and you will see a restriction if you size everything the same.

IMO for most things 1/2" is perfect. Its hard to overtax a 5hp compressor on volume issues with a 1/2" pipe ID. If you run a blast cabinet, save on the copper and put the air compressor right next to it.

 

[LS6 Tommy]

There is some danger that if a fire broke out, the heat could melt the solder out of the copper lines, causing a burst.

Never happen. If in the event of fire the solder melts it creates a leak. Nothing "bursts". The hoses will let go LONG before the solder melts. Not to mention, you shouldn't leave the lines charged when not in use.

Tommy

 

[CNGsaves]

{clip}
If you run a blast cabinet, save on the copper and put the air compressor right next to it.

^ ^ Your post was going alright until the "fire burst" comment and then above about putting compressor right next to blast cabinet. No, no, no.

You'll want blast cabinet . . . as FAR AWAY from compressor as you can to give air time to cool down and moisture fall out. See the TP Tools design, the blast cabinet is last thing connected to airline system.

Long runs of copper or black pipe steel take the heat out of moist air, letting the moisture fall out. Much easier/cheaper to just let the airline system capture the water and run it down a drip leg to be relieved. Around 40 ft of copper/steel will do wonders to produce dry air !

 

[finn]

I've got 3/4" black iron.

If I had to redo the system, I'd go with the Rapid Air. It looks better and is easier to reconfigure as the shop layout changes (and it will change).

 

[DC73]

I think the guy used 3 steel caster wheels mounted on a plate, . . . maybe this:

Related - post #12 on this thread shows a DIY tubing straightener using patio door rollers

Both of these are very similar to the one I saw. That one had red wheels on a wooden frame.

I like the idea of putting your air lines in the wall, but as some have suggested the cons to it there is also the problem with cooling the lines down.

I'm not too concerned with moisture in the lines. It's a fairly dry climate and my air uses are generally not critical concerning moisture. However, I could easily plan for something outside the wall if my needs ever did get critical. I saw a neat looking cooling coil of copper mounted between the compressor and tank in another thread.

Up to 50 feet long use 1/2”.
Greater than 50 feet use 3/4”."

Logically, 1/2" should be plenty for a one man garage.

I like CNGsaves suggestion of using 3/4" for the main run and 1/2" for the drops and that's the way I'm leaning at the moment. 1/2" everywhere will very likely get the job done but a hybrid system might be the best bang for the buck.

One advantage copper has over the RapidAir system is ready access to fittings and such at the big box stores.

Thanks to everyone for helping.

DC

 

[matt_i]

I just run the blast cabinet next to the compressor. There are 3 filters in series by that point, a 1" std bowl, a 1" coalescing and Trinco supplies their own 3/8" filter. Moisture is not a problem I've experienced...glass beads flow as you'd expect with no clumping or other issues.

 

[Kevin54]

I saved heaps by using inexpensive PVC, works for me.

Holy **** PVC Airlines

 

[DC73]

Holy **** PVC Airlines

Please read my post #28.

DC

 

[merlin601]

OK as a pipefitter with over 35 years of experience, some people really over thinnk the air pipe scenario. Type L copper is more than adequate, black pipe is fine, whatever is the easiest for you to install both are done everyday. If using black pipe put a filter in before the take off for your equipment, rust generally isn't a problem if you have a filter lubricator before your equipment other than a sand blaster. Any sanblaster should have a water separator before it weather black like or copper, because if iuts humid out your gonna get moisture in the system anyway, a lot of industrial applications throw all the rules out the window to save a few dollars and their stuff works fine for decads, so a home hobbyist system will work trouble free for ever with a few simple filters and moisture separators.
Hope this clears things up.

 

[djjsr]

Just an FYI if you're concerned about the pressure ratings for L and M copper.

Type M annealed (soft) copper at 100 degrees F.
1/2" is 494 psi
3/4" is 407 psi

Type M drawn (hard) copper at 100 degrees F.
1/2" is 850 psi
3/4" is 701 psi

Type L annealed (soft) copper at 100 degrees F.
1/2" is 722 psi
3/4" is 582 psi

Type L drawn (hard) copper at 100 degrees F.
1/2" is 1242 psi
3/4" is 1002 psi

 

[DC73]

PVC is perfectly safe for carrying compressed air as long as it's buried underground and if the above ground runs are fully enclosed in conduit or other metal pipe.

How many times do I have to say it? THIS THREAD IS NOT ABOUT PVC! PLEASE KEEP THE DISCUSSION ON THE TOPIC.

DC

 

[robert_dean]

OK as a pipefitter with over 35 years of experience, some people really over thinnk the air pipe scenario. Type L copper is more than adequate, black pipe is fine, whatever is the easiest for you to install both are done everyday. If using black pipe put a filter in before the take off for your equipment, rust generally isn't a problem if you have a filter lubricator before your equipment other than a sand blaster. Any sanblaster should have a water separator before it weather black like or copper, because if iuts humid out your gonna get moisture in the system anyway, a lot of industrial applications throw all the rules out the window to save a few dollars and their stuff works fine for decads, so a home hobbyist system will work trouble free for ever with a few simple filters and moisture separators.
Hope this clears things up.

As a "second" to this post, let's not over think things here! I would like to add, as a Journeyman Millwright for the last 20 years, I would install a main header "loop" and have drop legs. This prevents water/debris from collecting at the ends of a run and stabilizes pressures. A 3/4" header loop with 1/2" drops will be a lifetime arraignment. Either Black or copper, though I will say a copper system mounted properly will look VERY nice! aesthetics aside, it will stay somewhat cleaner internally than black pipe, though I doubt that it would be something you would notice. My shop is run with black pipe. Humidity in an pneumatic system comes from the compressing and rapid heating of the air, and even in drier climates, you will produce condensation in your system. So take care as to how you plumb your drop legs, and do yourself the service of adding the header loop and drip legs. For your current needs as well as possible expansion, 20-30 feet of pipe should provide you the benefits stated above. Good luck, Robert.

 

[robert_dean]

I guess I would also like to add, as have others, that threading black pipe by hand can be somewhat of a pain. A good quality cutting lube and a good threading die goes along way in making that job easier though. I would also counter that modifying or adding to a black pipe system is really the same amount of work as in a CU based system. However as you stated several times here, you have decided on a CU system, which I think is great. The more I think about it, unless you plan on doing any sandblasting or body work using D/A sanders and the like, 1/2" system would be sufficient for your current set up. Though personally I would do the 3/4"-1/2" combo....

 

[coljar]

bull .......... have black pipe for years never had or will have a problem

i did have a problem with copper, thats why i ripped it out and went to black pipe,

and yes i run a blast cabinet, and paint car parts all the time no water problems no dryer

one thing most people do that wrong is they tap the air line from the bottom alway go up and over then back down with a drip leg on each drop

and pitch back to the compressor with a drain leg at the start of the line

Agree. The oldest airlines in my older garage are 1/2", 3/4" , and 1 1/4" black iron and were installed in 1929. They are 86 years old and have been in continuous use 6 days a week since that time without any problems with rust. I was going to outfit my new garage with all stainless steel lines until I priced the fittings. I stayed with black iron.

 

[dadsEH]

please tell me your not serious. after everything thats been written about pvc airlines . why would yo go there?

Come in spinner .........

 

[Nursepeter1973]

I've got the design of the rigid air line system sorted in my head... but what exactly do you guys use for the "flexible hose" connection between the compressor and the rigid pipe? (I'm planning on using 1/2" copper as the price difference per 6 metres is $18 - $31.90 vs $49)

Something like this?

 

[Brunel]

I would also counter that modifying or adding to a black pipe system is really the same amount of work as in a CU based system.

I don't agree.

If you want to tee into an existing system to add another point, with copper you can just cut a tiny bit out of the line. You can normally easily get enough movement in the pipes to insert a tee which can then be soldered up. It's a trivial task.

With iron, be it black or galv, there's a lot more work involved in threading, and the chances are you will have to add a union so you can rotate the pipes to screw everything back together.

BUT iron piping is stronger and far harder to damage, which in some shops may be important.

 

[dfiler2]

I've noticed a couple of posts here where people say they installed black iron then posted pictures of galvanized. Galvanized pipe has its own problems and there are time when you don't want to use it, I believe air lines are one of those.

Quote from article

"Zinc owes its high degree of resistance to atmospheric corrosion to the formation of insoluble basic carbonate films.

Environmental conditions that interfere with the formation of such films may attack zinc quite rapidly. The important factors that control the rate at which zinc corrodes in atmospheric exposure are:

the duration and frequency of moisture
the rate at which the surface dries
the extent of industrial pollution of the atmosphere

In a persistently wet oxygenated environment galvanized pipe will corrode faster than black steel because the protective carbonate film (ZnCO3) that prevents oxidation cannot form under water. The rate of drying is also an important factor because a thin moisture film with higher oxygen concentration promotes corrosion."

 

[sberry]

How did they ever manage before the internet?

 

[koditten]

Too, true. Cary. Too,True.

 

[csp]

I used a hydraulic hose between the compressor and run of copper hard line.

 

[RAYJAY]

I don't agree.

If you want to tee into an existing system to add another point, with copper you can just cut a tiny bit out of the line. You can normally easily get enough movement in the pipes to insert a tee which can then be soldered up. It's a trivial task.

With iron, be it black or galv, there's a lot more work involved in threading, and the chances are you will have to add a union so you can rotate the pipes to screw everything back together.

BUT iron piping is stronger and far harder to damage, which in some shops may be important.

not really when you run black pipe you always add tee's for additions, my self i add a tee instead of a coupler section, and always add a couple of unions in the line so i can work on a section if needed,

you just have to think different running black pipe

 

[RAYJAY]

I've noticed a couple of posts here where people say they installed black iron then posted pictures of galvanized. Galvanized pipe has its own problems and there are time when you don't want to use it, I believe air lines are one of those.

Quote from article

"Zinc owes its high degree of resistance to atmospheric corrosion to the formation of insoluble basic carbonate films.

Environmental conditions that interfere with the formation of such films may attack zinc quite rapidly. The important factors that control the rate at which zinc corrodes in atmospheric exposure are:

the duration and frequency of moisture
the rate at which the surface dries
the extent of industrial pollution of the atmosphere

In a persistently wet oxygenated environment galvanized pipe will corrode faster than black steel because the protective carbonate film (ZnCO3) that prevents oxidation cannot form under water. The rate of drying is also an important factor because a thin moisture film with higher oxygen concentration promotes corrosion."

mine in post number 17 is black pipe painted with hammer mill paint....... .....

 

[Average_Joe]

Just bought the 3/4 Rapidair Maxline kit m7500 at Northern Tool for $151.89 (incl tx) delivered to the store. Its on sale for $159.99 and used a $20 coupon code from retailmenot.

 

[MrBreeze]

Just bought the 3/4 Rapidair Maxline kit m7500 at Northern Tool for $151.89 (incl tx) delivered to the store. Its on sale for $159.99 and used a $20 coupon code from retailmenot.

It would be great if you started a new thread, or added to your garage build thread with your installation experience and findings.

 

[dr_clyde]

We just installed a new 60HP screw compressor to run the packaging line at the brewery. That feeds the whole plant on a 2" black pipe. 3/4" main trunk with 1/2" drops will work excellent in a home shop.

If it was my shop, I would do copper over black pipe because it looks nice, and unless you have a power pipe threader, its much easier to braze or solder the pipe than run a hand threader all day. That said, it is accepted in industry to just have threaded black pipe.

Either choice will work splendid, it all comes down to cost and ease of installation for you specifically.

 

[Average_Joe]

It would be great if you started a new thread, or added to your garage build thread with your installation experience and findings.

Nice contribution.

 

[sberry]

In a home garage chances are a fairly simple manifold could be done with ready mades, they have a super selection of *******.
This is an endless issue but the 3/4. 1/2 thing is really over done. Great for body shops and shops with multiple men and long runs, well in excess of 100 ft.
I like 1/2 all the way, its what the old masters have in their garages. Less leak, moves the air along to a drain, 4 times as big as the hoses in the system and quite a bit bigger than a 1/2 hose, can use re-use a single selection of fittings, fit it all with a 440 Channeklock and normally fit with only one union with a T somewhere to tap on if needed.
I will backthread a pipe or 2, take it out, fix or add before adding a half a box of extra fittings and unions. Some of these DIY jobs, while they may be impressive to the home crowd really look bad and some take as many as 5 or 6 fittings to install a T.

 

[MrBreeze]

Nice contribution.

Not sure if that is sarcasm? I am genuinely interested in learning from your experiences with the RapidAir installation. Was trying to be respectful of the OP thread in not derailing the focus on copper air lines.

 

[sberry]

We modified our sandblast line a while back. It is another one that its the second time I moved it. Unscrewed a hydrant, removed reducing bush, added a T, routed a new hydrant a few ft, used same reducing bush.

 

[sberry]

Take a sandblaster for example, 2 different case but I can make 60 cfm, I use a 1/2 black pipeline for 20 ft and 25 ft of 1/2 hose. I can make 60 but can use more, when you read a chart there seems like a lot of loss but before long am running low on air, adding a bigger pipe wont help, in fact make it a little worse in an operation as hugely in efficient as sandblast. So big that a couple pounds drop across the air delivery for this short time gets in to figures where we got to start to split a % point.
Wont effect the operator at all.
Look at rental comp, 70 hp engine can make 185 of air all shot thru a 3/4 hose.

 

[sberry]

By GJ standards we would have to replace the 3/4 with 1 1/4. At home all the losses are thru the secondary, the main trunk is almost no concern especially with 2 stage comps. The point is to let enough air thru to do the work, not to dump as fast as we can.
If any of this actually becomes a problem then the equipment is too small, messing with the piping is not going to fundamentally help much.
Shortening the hose to a bitty air comp helps the most to deliver ultimate power.
clyde,,, what is the pipe size coming from the comp in case? There are a lot of reasons to up the manifold a size in plant work.
This sounds a bit like ramble but the intent is to get a feel for the "reactions" of what we are trying to pipe and wire. Example. My well pump is down hole. Its 240 ft. I have 3 hp and size all the exit pipe in the system, tank, valves 11/4. I pipe this to my shop and split to 1 inch and most of the rest of the piping is inch service. 2 places we have 1 1/2.
Comes out of the pump at 1 1/4 to 1 1/2 after the check valve to the last just below the seal back to 1 1/4. We run 400 ft to across road to my Dads and mine is added with inch.
We upsize once for long run and 2x for double long run. We add another huge insult to it all by being on a well.

Plants the same way, the brewery is well served by the 2 inch. You could sandblast all it would make thru a 1 1/4 its likely ported with but upsizing an air main in a plant is a good to great idea for a couple reasons, 1 being this is ran 24/7, don't want to wait on demand spikes, can add additional equipment or changes and is still a common size able to be fit off the shelf.

 

[sberry]

In a class bigger shop 3/4 or larger air impacting is a concern for a size jump in pipe, we start to approach lengths in excess of 100 ft, home time figures are closer to 60 ft. Joe Home time views the 20A circuits in his garage the same way. Reality is intermittent load of 13A max on 40 ft of wire, many way less.
I got a fairly busy place but other than a walk in cooler and larger well the loads would be similar to kitchen counter top and appliances. A little intermittent air and most the rest applied 1 at a time.
Air almost always 1 user at a time of any concern. 60 ft of 1/2 to the paint booth and if I am spraying do not have 2 or 3 other guys sanding. Can spray on 3 hp.

 

[59 wagon man]

3/4" is a waste in a home shop unless you have multiple tools working at the same time . after all our hose reels and adapters, quick connects and usually even the tools are only 1/4" or 3/8". That being said i do have 3/4" copper air lines . i am a plumber by trade so it was no big deal. But Bigger is better is the american way

 

[Fixnair]

Nothing at all wrong with copper. 1/2" will be adequate for up to a 5 peak HP compressor. As far as extra volume goes, what for? Sure it will take a little longer for you to use the stored air but then your compressor will have to run longer to replace that compressed air. No advantage there. Unless you have some need for providing large volumes of air 1/2" will do you fine.

 

[59 wagon man]

[ Some of these DIY jobs, while they may be impressive to the home crowd really look bad and some take as many as 5 or 6 fittings to install a T.[/QUOTE]
if you are referring to the fact that some people will point the tee upwards and then roll back down towards the ground this would be a fairly common steamfitter and recommended by some manufacturers also

 

[Average_Joe]

Not sure if that is sarcasm? I am genuinely interested in learning from your experiences with the RapidAir installation. Was trying to be respectful of the OP thread in not derailing the focus on copper air lines.

Sorry about that, thought your post was sarcastic. Anyway, I thought the OP or someone had posted about the rapidair stuff and wanted to let them know about the sale.

I will be posting pics of my installation and general garage progress soon. It has been way too long...

 

[MrBreeze]

Sorry about that, thought your post was sarcastic. Anyway, I thought the OP or someone had posted about the rapidair stuff and wanted to let them know about the sale.

I will be posting pics of my installation and general garage progress soon. It has been way too long...

Next to impossible to denote tone and intent on a forum - No harm, no foul.

The RapidAir is a logical alternative to copper, and I have been considering both.

 

[sberry]

[ Some of these DIY jobs, while they may be impressive to the home crowd really look bad and some take as many as 5 or 6 fittings to install a T.

if you are referring to the fact that some people will point the tee upwards and then roll back down towards the ground this would be a fairly common steamfitter and recommended by some manufacturers also[/QUOTE]

I agree that it would be common steamfitter ad there is nothing fundamental wrong with it.

 

[sberry]

A lot of things where we copy 1 feature of an intergrated design don't always work that well or end up not being worth the cost or effort. This does not apply to everyone but mostly to the "how to" "how much" type of questions.
I worked where it was common to put a T in anywhere, no one ever cared if you lost a little for a few seconds even if multiple men were on it.
Many a job we run 100 ft air line and T for chip and needle scalers.