I ran this by on a garage talk forum, so far my reply has been "I won't help you because I am not putting this website at stake if something happens" yada yada yada.

Hopefully someone here will answer my questions. Yes, I know PVC isn't recommended, etc.

Start Thread:

Okay, so I am going to run 1 1/4" PVC line. Yes, I chose PVC because I have heard from a few people locally that it is that much easier, cheaper, and it will work fine. People that have done it and used it for many years. I am still kinda skeptical, but these people I trust.

Now, I have a couple questions.

1. I am going to run 50 feet from one corner, and from that same corner, 20 feet the other way. I think I read somewhere that with a bigger feed (1.25") that you will gain volume, but lose pressure, is that correct? I will be running 125ish PSI at my main regulator, which will be between the tank and where the PVC will start. Also, my 50 foot and 20 foot feeds will be 11 feet high, thus needing to drop 7 feet or so, so that is going to be more volume. I will have a total of 5 drops. Rather have more than I need then kick myself later.

I know you like pictures so...


Click here to see larger (5.0 megapixel) version

That is the area that I plan on doing the lines at. The wall that is on the right will be my 50 foot feed. And then the wall that the electrical is on will be my 20 foot or so lead.

2. How do I get around this little obstacle? I would rather not have to square around it because I think that would hurt air flow? Maybe I can get something that is more circular? Or will it not matter?

Picture...

Click here to see larger (5.0 megapixel) version

I will only need to go over the one electrical conduit there, as that light is 10 feet high, and the feed will be at 11 feet.

Also, I am probably going to run the feed that goes from the compressor and up to the 11 foot mark directly in the corner, if I can find the T I would need to make this happen, if not, I will run it a couple inches in on the long wall.

plastic is fine just shut down the compressor at night, that way if a line bursts the compressor wont run all night. also you should make the lines run down hill back to the compressor, that way the condisation ( sp ) runs back to the compressor not to the tool. next at the turns you should put in a drop with a bleed valve to drain the water. if you are worried about flow you can use electric pvc condiut bends in the corners, its scd 40 just like the water type pvc, but i dont think it would make much of a difference.
and MAKE sure you use primer and you might want to put a loop for expanstion

I had PVC air lines in my body shop with 6 monkeys using them all day. I had them for 15 years. We had the the "T" fittings fail probably 6 times. I used 3/4" lines throughout a 4000 sf building. One precaution. When the plastic fails they shock the whole line hard. This caused other fittings to crack as well. I second the shutdown suggestion over night. BTW: I recall the PVC was rated for 400 psi at 80 deg far.

I have had 1" pvc air lines in my shop for over 20 years now and never had a problem.
My max air pressure is 175psi.

Make sure that you attach the piping to the wals so it does not move under pressure. Look at the ratings for PVC piping and you will notice that the larger the diameter the less maximum pressure it will hold.

Schedule 80 pipe and fittings is thicker than traditional Schedule 40.

Keep PVC pipe out of sunlight or paint the piping. UV sunlight can turn it brittle.

Larger piping aids air volume/ flow and pressure builds at the final restriction point. 1-1/2 may be over kill unless you need a lot of airflow. Run your master horizontal trunk line high up on the wall and angle it slightly back to the air compressor so moisture drains back to it. With your vertical piping that drops down the walls to your air connections, build in a moisture collection pipe by installing a tee for your air fittings and a foot long pipe below it with a drain valve. I have a master pressure regular and water seperator at the connection of the compressor. I run an additional water seperator at a couple of my hose connections for when I'm painting. DH

Thanks guys. I knew I should have just came here first.

They are telling me on the other forum that many people have been injured and killed with PVC, and I am jeopardizing everyones safety that is in the vicinity, and yada yada yada. Why is it then that everyone that runs it swears by it? Oh no, a connection failed, I can fix that.

What I can't fix is my pocket book to have enough $$$ for copper to run. Plus the headache of install.

I have all the plans all drawn out and ready to get started on Friday. I am not at my warehouse very often, so the compresisor is always shut down unless I am there and know I will need air tools.

We are going to clamp it every 3 feet, then do a clamp above and below the drop where the fitting is, as below the fitting will have a drop for moisture to collect in. I was told this is the right way to do it, and for a couple dollars more, it is worth it to me. But not the minimum of $100 I will save going to PVC over copper.

Yeah, I planned on running the thicker PVC, I guess it is called Schedule 80, not sure though.

schedule 80 is the way to go. think about adding a few extra t's on the long runs. you can cap them and add hose fittings at a later date. it's easiest to fit them now than later. an extra long verticle piece with a petcock on the end will make for a nice drain. slightly pitch the lengths going to the drain.

k

QUOTE (iiibdsiil @ Mar 16 2005, 12:24 AM)

They are telling me on the other forum that many people have been injured and killed with PVC, and I am jeopardizing everyones safety that is in the vicinity, and yada yada yada. Why is it then that everyone that runs it swears by it? Oh no, a connection failed, I can fix that.

If you are worried at ALL about safety, then make a metal shroud around the Ts, and any joint. Maybe get a REAL BIG (like 2") copper T and cut it down the middle, then mount it directly over the plastic T mounted on the wall. You can easily fix it, and it'll make sure a that any plastic doesn't shoot off and hurt anyone. do the same at any joint, and you'll be fine.

I'm not worrying about it breaking. Too many stories about it working flawlessly and no one has said "It happened to me" about it breaking. Let alone to anyone they know.

I am gonna have a drop every 10 feet, I think that should work. 7 drops, one person working, should be plenty. Plus I have all sorts of splitters and stuff if I need.

Thanks guys.

smack on a piece of 80 with a hammer. it's pretty tough. the only time it MAY explode is when you drive into it with a car when it's charged with air. it will install 4x faster than copper. the correct primer/etcher and glue are essential.

k

Screw the metal pipes, there will be moisture in there and at some point it will rust - do you need that stuff in whatever you are throwing air at? Paint, tools etc??

I head some harsh things on PVC when it fails (and mostly from impact from another object), there is also a grey PVC which is heavier duty and more expensive. You can also do copper pipe, it won't rust. But you can run the lines very high in your shop, so the chance of impact would greatly be reduced.

As for getting around your conduit, I would step the line out away from the wall on some wooden blocks as spacers, then come back in tight to the wall.

I have read that you want a 2" drop for every 20 feet of horizontal run, and then have a drop at the very end of your run with a drain valve (which is opposite of what others are saying, but I don't see much difference either way). At every service drop, have a drain valve at below your stub out, it will act as a last ditch effort for water collection.

If you do an air/water separator, give yourself at least 20 feet of piping first, so the water has a chance to condense. I got a 3/4" unit from harbor freight on sale for cheap.

There was a good article on design on an oldsmobile fan site, I will look for it and post.

I have seen PVC explode and I am very glad I wasn't near it... that said I think the guy did it wrong...he ran a 3" pipe and then necked it down cause he wanted more volume to make up for his small compressor tank. Well a fitting failed and it punched a hole in the sheet metal wall where the fitting blew up and also pushed the pipe going towards the compressor through another wall. One of the guys was in the shop and had been within 5ft of that fitting about 5min before it failed, had he been near it I bet it would have hurt him badly.

So, not saying you cant use it, and it sounds like you are going to do it right, so you probably wont have any issues...but I went with copper in our shop, and it turned out to be cheaper than PVC if I remember correctly.

Tony

Well, I will get a definite price on Friday morning when I go to do this, then I will make my final verdict. I agree that PVC is not the best thing to do, but that is the only horror story I have heard from it.

I will be using is so little that if it fails with 500 hours of usage, it will take me a long while to use that up. I will probably be in a new location by then.

About the blocks of wood, I am trying to not put any pressure on the PVC that isn't necessary, and bending it like that seems kinda not what I should do. Once I have the stuff in my hand I will figure it out.

Crap, how am I supposed to do 20 feet of line first if I am gonna be 11 feet in the air. I can't have the water seperator that high if I want to be able to empty it. We do have a fork lift, but that would just be a hassle.

Everything I heard was have the end that will be furthest from the compressor lower than the compressor, 5" for 50' I believe. But then here, ya'll are saying let it drain back into the tank...

http://www.oldsmobility.com/air-compressor-piping.htm

This is a good tech article. You do a separator at your drop. And from what I gather, you want eveyrthing flowing away from the compressor (water), as the water will just get re-atomized as the airflow passes through. makes sense to me, but what do I know?

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Okay, so the seperator doesn't have to be in line then?

No, nevermind, it does. But then I need one for each drop, 5 total. Crap. If that's the right way though, then I will do what I need to do.

These ones have a single drop and air separator, then use that drop for pure air, the other drop is for air/oil (which I would do downstream of your clean air). You will need several separators if you do each drop if you cannot do it in line. Read the articles, it will help make more sense. I like the stepped tubing at each drop as well as the rise over from your horizontal lines for the drops.

One idea may be to use 25 feet of air hose, and hook that up to a separator - then do your hard lines (you could have it coiled up all neat and out of the way).

Thank you for coming up with the articles.

In regards the air hose, wouldn't that be like backwards? Since I am running 1.25" PVC, woulding I want something bigger coming from the compressor? I know I can get 3/4" hose, but still seems to work against the cause...

Yeah, I know, I probably won't see a difference since there will never be more than 2 people using air tools at a time...

I had a reply but the bbs took a dump. Here goes again. A quick draw up of something you may want to ponder. Note the drops also have a dogleg step up, water flows downhill and will head down to your drops. the drop continues about 8 inches or so below your service stub with a ball valve - water trap. You can also get AFR's that will drain automatically when full, with one of those you can mount it up high and forget about it (except when it drains the water on your head).

The hose idea, was just an idea. You will get a restriction anyways coming out of your compressor, it would be a 1/4 or 3/8 output anyway. And also you will have to neck down to get into your AFR's and whatever tool that is using air. Also note that you will be setting your final pressure at your AFR. Full blast at the compressor, scale down at your AFR - make sense?

Image is too small to read, at least I used a red pen instead of a crayon..

Each drop has a ball valve for draining water. Drain leg at the end of your run. the first drop goes to an air/water separator/regulator, horizontally shoots out to T connectors with quick connects, 2nd drop for air/oilers (if you are going to use something like that).

Thanks a bunch. My compressor is only running 125 PSI anyways, sucks.

I'm not sure what kinda restriction I will get off the compressor, I have like an 1.5" hole in the side that goes down to a .25" now, so I am going to see if I can get a 1.25" flex line (steel braided) to go from the compressor to the tubing.

Be sure to post pics as you go, I'd love to see how you will do it!