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  • ERBenoit
    replied
    Another plus to the copper, the pipe won't rust if you have, or get "wet air" as the B/I pipe will. If you have "wet air", rust flakes will eventually occur. Unless you have "dry air" the compressor condensate will start the rusting process for you. One of the last things you need is another source (B/I pipe)of rust flakes flying around in the system.

    Consider your filter/dessicator locations also.

    Leave a comment:


  • Last Old Dog
    replied
    <font face="Verdana, Arial" size="2">Originally posted by railfancwb:
    Air under pressure is more like steam than water. With water under pressure, since it won't compress, a tiny leak drops the pressure to atmosphere quickly. Air and steam both compress and store far more energy than water for the same gauge pressure. </font>
    For all you spud gun - potato cannon - starch launchers, we all know PVC must be severely de-rated for temps on either side of 73.4F. Whilst temps of 100F (de-rate by 50%) may be rare, shop temps down to the high 30's or low 40'sF may occur in many geographic areas. PVC under air pressure can GRENADE at the slightest provocation. The resulting shards are as destructive to the human body as exploding glass. And the remaining pipe flailing about will beat the c^#$ out of whatever it can reach.

    Keep in mind, just because it is marked "SCHEDULE 40" does not mean it is pres rated, it MUST be printed on the pipe. PVC for compressed air is scary.

    Copper is my choice, and a peripheral loop around the shop provides two feeds to any drop. A tank at the opposite end can act as an accumulator for short burst high volume demands.

    Last Old Dog

    Dawg is pretty sick, I type for him, please excuse my feeble efforts

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  • GregC
    replied
    1/2 or 3/4" copper is the way to go. It last forever and has a working PSI rating of something over 1000PSI. Easy and cheaper to install than black pipe.


    Leave a comment:


  • irontoart
    replied
    I beleive PVC also degrades when exposed to UV light for long periods

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  • railfancwb
    replied
    Air under pressure is more like steam than water. With water under pressure, since it won't compress, a tiny leak drops the pressure to atmosphere quickly. Air and steam both compress and store far more energy than water for the same gauge pressure. Steam and its superheated water also store temperature energy... Charles

    Leave a comment:


  • bobw53
    replied
    &gt;&gt;Well the reason this less than really knowledgeable person wants to use steel is that I can't solder copper good enough to hold water yet alone 130PSI. :-)


    Copper is really easy to solder, clean it with sandpaper, scotchbrite, wire brush, whatever.
    Slop on some flux, get it hot, and touch the solder to it, done. However, buy the greasy kind of flux, that white non-staining paste crap they sell at Home Depot and in the soldering kits is pretty close to useless, you might as well glue the pipes together with elmers. As for heat if you have a oxy/acetylene torch, its a lot quicker than a $10 propane job. Just get it hot all around, and then concentrate your flame a bit away from your joint, in the direction the solder needs to flow, touch your solder to the joint, and presto.

    I'm far from a pro, I've only plumbed the shop at work and previous to that had done very little soldering successfully. Just my expieriences.

    We ran about 300 feet of 3/4 copper, and the only leaks were the result of the white pasty flux. If it does leak, its an easy easy fix. We didn't run drops, but a downslope on all main lines to drains and then pointed the outlets upward. We are also running a big dryer near the compressor.

    Another plus of copper as opposed to steel, is that it is so easy to add another outlet, pipe cutter, add a T, solder and your done in 10 minutes, total cost of about 3 dollars.

    Leave a comment:


  • Duct Taper
    replied
    At our local high school auto shop a piece of equipment was being moved by the students and it bumped into the PVC air line. The line shattered. Nobody was hurt but the line was immediately replaced with steel pipe.

    Maybe PVC can handle the pressure and maybe the oil doesn't affect it, but mechanically it is not safe.

    Leave a comment:


  • J Tiers
    replied
    <font face="Verdana, Arial" size="2">Originally posted by suprdvn:
    Anyone notice that the compressor pump in the picture above looks like a mans face wearing a goofy hat. </font>
    Hey, anyone who saw that deserves to see this too:

    http://www.animationarchive.org/2006...achinalia.html

    Leave a comment:


  • snowman
    replied
    I was just at home depot reviewing the price of pipe.

    I thought Adrian was dumb for buying his pipe from home depot...I'm soo much smarter for buying it from a steel supplier.

    Well, it's actually cheaper from home depot. Weird

    Anyway, back to point. 1/2" black pipe costs .789 per foot (10 ft lengths), 3/4 costs .989 and 1 costs 1.289. For a 35 foot run, I'd just buck up the extra ten bucks and put in 3/4...and know that you wont have to replace it later.

    -jacob

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  • litman252
    replied
    Well the reason this less than really knowledgeable person wants to use steel is that I can't solder copper good enough to hold water yet alone 130PSI. :-) Once I look at these compression fitting's I'll make up my mind on what to use.

    My old boss used PVC, thick stuff. It worked good for a couple of years, then it shatterd and scared the heck out of them. He now has black pipe.

    Tony

    ------------------
    I'm Learning, have a long way to go

    Leave a comment:


  • japcas
    replied
    I can understand that it shatters when it breaks but some pvc is rated to 600psi or more which is a lot more pressure than a compressor will ever put on it but I hadn't thought about the possibility of the compressor leaking some oil into it which could compromise it's strenght. Thanks for the explanation barts.

    Leave a comment:


  • barts
    replied
    You don't use PVC for two reasons:

    1) if it shatters it's like shrapnel; it also doesn't show up on X-rays. Some failure modes include lengthwise shattering.

    2) Some compressors have leaked oils that degrade PVC, making the above problem worse.

    Go with copper. Easy to fix or alter, light and safe. Yes, it's a few more $$, but go for the safety.

    - Bart

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  • Mcgyver
    replied
    isn't that the stuff that tends to shatter into shrapnel if it lets go? i think that's why

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  • japcas
    replied
    I'm not trying to steal the thread but can someone explain why you shouldn't use pvc pipe for air lines. I have seen it done with basic pvc rated way over what air pressure will be on it but it was standard water pipe and some people have told me it shouldn't be done but they never can explain why it shouldn't be done. Can anyone enlighten the ignorant like me?

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  • charlie coghill
    replied
    Litman look at using copper pipe and soldering the connections. I used 3/4" copper pipe. Been real happy and have not made any changes to the system in 7 years.

    Leave a comment:

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