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Plumbing for shop air?

 
sdmuleman said:
I used 1/2 pvc for mine after some consideration of risk. Conclusion I came to is that PVC air lines is a bit like 2 piece rims - perception of risk has considerably outpaced reality, and while it's not 100% safe, it's a pretty minimal risk.

Much of the concern stems from various controllable problems - poor quality joints failing, concern about high temperature strength, degrading due to sunlight, impact damage, etc. Moderate competence does a pretty good job of controlling this.

The only real danger to me is explosion risk and shrapnel, but that's also not that significant if you use small piping. Can also make sure pipe is located in such a way that shrapnel is unlikely to hit you as well.

Wouldn't use anything bigger than 1/2 - highest safety factor and also smallest amount of energy if it ruptures. Larger sizes have enough energy to be genuinely dangerous, but small diameter means low energy and small fragments. Doing some rough math, the energy in 1" of 1/2" air line is enough to accelerate 1 gram to roughly 100 mph. In the real world only some energy goes into fragments, and there's likely multiple ones each taking some amount of energy. Bottom line, outside of a fragment hitting pointy end first in an eye it's unlikely to get an injury worse than a minor bruise or cut.
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Keep telling yourself that.

I heard an air leak under a bench top at a buddys shop and walked over to check it out. Just as I bent over and touched it, that fucker blew and shot the quick connect with 14" of pipe still attached at me. Fortunately, it hit my forearm and only grazed my head instead of drilling my face. The noise was deafening and the blast of condensation hit me in the face soaking me. When the guys picked me up off the floor, I had to ask them if it was blood.

I got lucky that day and I'm glad it was only 1/2" pipe:flipoff:
 
cj3a said:
Hard to beat this unless you are getting the buddy hook-up
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I used this kit to plumb our fabrication area at work and have had zero problems or leaks. It comes with the tools, hangers, blocks etc. I think it was just under 200 when I bought it but it would be worth the price listed here. The fittings are outrageous when bought individually though I will admit.
 
TTMotorsports said:
Even the RapidAir kits are PEX. They are PEX-A or something but even that isn't rated for over 100 psi at above like 80 degree's
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"PEX tubing sold in the US has a 630 HDB rating, meaning it has a pressure rating of 160 psi at 73°F. PEX pressure ratings are 160 psi at 74°F and 100 psi at 180°F'
 
cj3a said:
Hard to beat this unless you are getting the buddy hook-up
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I was looking at the knock-offs of these on Amazon yesterday. What appears to be the same kit can be had for around $170. Pictures are almost identical to the rapidair too.






Biggest problem I have with these is that the extra fittings and manifold blocks start adding up $$$. I want to put in at least 10-15 drops around the shop. The kits only come with 3 blocks and the additional blocks are $25, $10 for the line the NPT fitting, and $10 for a tee....so every extra drop runs $40-45. My plan for pex was goign to just use a drop ear tee and it'd be under $10 per drop.

But, I do like everything else about those systems better than straight pex. Might just need to suck it up and spend the extra cash on it and do it right the first time.
 
carslut said:
i have 1" PVC in my shop, its 13yr old and zero problems
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Had the same in a shop I used to work at. No idea how old it was, but had been there a while. Had a hard freeze, and about a week after everything thawed out. We started having one failure after another.

Shop is all copper now
 
arse_sidewards said:
Most things people circle jerk about the safety of fall into that category because the people who circle jerk about safety are the kind of people never do shit so they don't understand what is and isn't controllable or to what degree.
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And they get hung up on OSHA and the manufacturer warnings without understanding to what degree it stems from a few idiots. Again, much like tire shops and 2 piece rims.
 
Last shop I was in we had 3/4 pex/rapidair stuff, and also 3/4" flexible hose. I hated the 3/4 hose - seemed to bulky and heavy when using air tools. Went back to 3/8 hose and like it much better. Planning out a new air system right now, and wondering how everyone derived at 3/4" in the pex recommendations above. Why not 1/2?

The way I want air to run in the new shop setup, it looks like I'll be needing ~ 200' - wondering what difference I'd notice it I had 1/2 instead of 3/4. Air hoses will all be 3/8, running things like die grinders, plasma cutter, blowgun. Upright 120 gal. compressor but probably not huge demand on the system on a regular basis.
 
1/2" pex (and fittings) have a smaller ID that 1/2" copper or pipe.
 
3/4" copper main trunk and and 3/4 or 1/2 copper drops, probably overdone with stay brite 8 solder to hold it all together. Easier on me than trying to get threaded pipe installed and easily reconfigurable when I needed to make changes. Ran a few loops up and down the wall behind the compressor to cool air entering the system and it does seem to help drop water out of the air with extended use. As others mentioned, ball valves where they make sense to isolate bits of the system, drains at the drops and low points. Also, to hep keep and water out of the drops, I tapped off the top of the main line with a "loop" to the drop vs. just a tee pointed down.
 
desertPOS said:
Last shop I was in we had 3/4 pex/rapidair stuff, and also 3/4" flexible hose. I hated the 3/4 hose - seemed to bulky and heavy when using air tools. Went back to 3/8 hose and like it much better. Planning out a new air system right now, and wondering how everyone derived at 3/4" in the pex recommendations above. Why not 1/2?

The way I want air to run in the new shop setup, it looks like I'll be needing ~ 200' - wondering what difference I'd notice it I had 1/2 instead of 3/4. Air hoses will all be 3/8, running things like die grinders, plasma cutter, blowgun. Upright 120 gal. compressor but probably not huge demand on the system on a regular basis.
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My plan with pex was to go with a 3/4" trunkline loop around the ceiling and then 1/2" drops....except I'd probably do a 3/4" drop for high volume things like my blast cabinet.

Now I've almost talked myself in to one of the rapidair knockoffs I posted above. The kits all come with 3/4" tees and fittings for the drop and it looks like it'd cost more to get the 1/2 fittings so I'd probably just stick with 3/4 all around.
 
bgaidan said:
My plan with pex was to go with a 3/4" trunkline loop around the ceiling and then 1/2" drops....except I'd probably do a 3/4" drop for high volume things like my blast cabinet.

Now I've almost talked myself in to one of the rapidair knockoffs I posted above. The kits all come with 3/4" tees and fittings for the drop and it looks like it'd cost more to get the 1/2 fittings so I'd probably just stick with 3/4 all around.
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I wouldn't worry about the blast cabinet. Whatever pressure regulator and drier is bolted to the side is probably the restriction by a mile no matter what you do.

I did all 3/4 drops because the cost difference was negligible.
 
wvracer821 said:
I finally got my compressor all fixed up and running good. its time for air line plumbing in the shop now and ive been doing some research on the most economical way to do it. I snagged some pex-al-pex (MaxLine from RapidAir) from work out of the dumpster and i wanted to use that but after pricing out the special fittings im not sure i want to use it since ill have a small fortune in the fittings. ive considered black iron pipe but it seems like lots of people have rust issues over time. i briefly looked into using regular pex but the internet had a lot of negative feedback on that. however, I have not found anyone that actually used it and it failed miserbaly. Has anyone here used regular pex for air on here?
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All my service truck air systems have been plumbed with 3/4" nylon air brake tubing.

I personally wouldn't be scared of pex.
Either way I'd spend some time making drops with shutoff valves/drain valves that allow them to be physically bolted or screwed to something.
 
Zero downside to pex IMO.
Not the best but the cost/ease of use far out ways the cons.

PVC is not the best choice now and has no advantage over PEX besides possibly cost.
 
tsomctl said:
Whatever you do, don't use pvc. If it bursts, it shatters and throws shrapnel everywhere. Copper would be faster than threading iron, but more expensive.
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I work for a PVC mfg and we definitely do not authorize Sch40 or Sch80 PVC for compressed air systems. If it's under pressure and someone hits it with a pipe wrench, then yes it can shatter. Now all that being said, I use Sch80 in my shop with tees that have brass inserts for the QD fittings. Works great, and no nuns have died yet.
 
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Murdered out:



I think here or Pirate there was a thread about buying rolls of airhose, then cutting to whatever lengths you want and using pushlock fittings for the ends. Anyone know what I'm talking about? Seems like it makes a lot more sense than buying a bunch of premade air lines... Going to go with 3/8" for the flexible hose. Parker or ?
 


Product links in the description below the video. There's one way to make your own hoses. Anyone done something similar or used something else?
 
Black iron pipe for the through-wall connections and main vert in my garage, then 1/2" pex crimped with crimp rings for the longer runs. Works mint.

I've read that you need to keep pex away from UV, so inside the ceiling works well.
 
chaplinfj60 said:
could you use the crimp rings for pex tubing also? or are they too thin and cut hose? hmmmm
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The tolerances on the rings vs. the OD of pex is pretty specific. And they only crimp down a tiny bit....doubt they'd be enough to crimp on to rubber hose.

I actually have a set that I think was for oxy/acetylene hoses that I found in one of my old company trucks. Can't remember what hose sizes it covers, but I'm sure it'll at least do 1/4" and 3/8". Really wish I thought about it when I fucked up an air hose and ended up just throwing it away. :shaking:
 
Lee said:
Today there's really no reason not to just use PEX.

I got chastised for using PVC for a DIY Franzinator at the old place. My grandpa's old machine shop has been plumed in PVC for 40+ years and nothing's blown up yet. Ceiling drops, with springy hose coils at most machine stations, plus a few quick connects on various walls. A lot of it is protected behind spray foam, though it was there was a good 15-20 years before it got spray foamed.

Just depends on what level of risk you're acceptable with.
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Anyone know where to get 'springy hose coils,' or what the proper terminology would be to search for? I was trying to look them up on McMaster and striking out.


Also, after cruising through page 1 again, thought I'd point out there is a huge difference between the general pex you find at homo depot and the 'pex' in the rapidair kits and kits linked in this thread. 3/4" pex for water has an OD of 7/8" I believe, while the stuff for air is 1" - they're thicker and have a layer of aluminum that makes it a little more difficult to bend as well. I was going to get some of the 90º pex 'support' pieces to help with throwing a few 90ºs into the mix, and it measured too small and no way it'd work. Ended up getting a 3/4" conduit bender to help clean up some of the bends I'm going to do. Got ~ 60' plumbed today, out of 200' total from the kit I linked above. Seemed like the best deal for 200' and hardware for 5 drops, and everything looked good when it showed up today.

I precut a few pieces, dragged out into the sun and let them get hot, then pulled them through a 15' piece of 1-3/4" steel tube to straighten somewhat. Worked better then my first method of hanging and trying to pull off the roll:homer: Holds it's shape pretty well, but heat softens it up quite a bit
 
bgaidan said:
The tolerances on the rings vs. the OD of pex is pretty specific. And they only crimp down a tiny bit....doubt they'd be enough to crimp on to rubber hose.

I actually have a set that I think was for oxy/acetylene hoses that I found in one of my old company trucks. Can't remember what hose sizes it covers, but I'm sure it'll at least do 1/4" and 3/8". Really wish I thought about it when I fucked up an air hose and ended up just throwing it away. :shaking:
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If you find PEX cinch rings that fit snugly around your air hose they work well in my experience.

desertPOS said:
Also, after cruising through page 1 again, thought I'd point out there is a huge difference between the general pex you find at homo depot and the 'pex' in the rapidair kits and kits linked in this thread.
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Yes, regular PEX vs PEX-AL-PEX.

Aaron Z
 
aczlan said:
If you find PEX cinch rings that fit snugly around your air hose they work well in my experience.


Yes, regular PEX vs PEX-AL-PEX.

Aaron Z
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Just to make sure my earlier post was clear, I use regular plumbing PEX for my garage air setup with crimp rings. Has been working great for 6 years at 150# of line pressure.
 
desertPOS said:
Anyone know where to get 'springy hose coils,' or what the proper terminology would be to search for? I was trying to look them up on McMaster and striking out.
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Air brake coiled hose is a readily available option.

download.jpeg
 
Lowrollin70gmc said:
Air brake coiled hose is a readily available option.

download.jpeg
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Ok I guess that or any kind of coiled hose could work. I was picturing more like what would be in a commercial kitchen above the sink, where you can grab the water spout and pull it down to use.

Like a shop grade version of this:

D4B29897-3D0E-4F3A-9844-C172DFDC639A.jpeg
 
Firstram said:
I'll bet they are more durable than the crap from harbor freight.
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The newer blue HF ones aren't bad, though the threaded fittings are plastic. I use one for my CO2 OBA setup and haven't broken it yet. The old orange ones they sold were pretty shitty....but that also used compression connectors on the end so they were at least field repairable. Most of the ones you can buy now are molded and you can't repair them.


These come out to a little cheaper per each than the HF ones and they have brass fittings AND come with quick connects pre-installed.
 
I bought a length of regular air hose and ran that. Been here 13 years with no issues hooked up to a 80 gallon 2 stage.
 
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