b;ack pipe or pvc for hardlines?

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overtimin
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b;ack pipe or pvc for hardlines?

Post by overtimin » Wed Dec 02, 2015 12:02 am

which one is best for a semi budget build in the shop. I want to run hardlines and plum up 2 tanks to one big compressor. I run 170 psi and im not sure if pvc will hold over time. ive been told by many that's what thry run just would like some opinions.

what do you guys run/recommend?

also switching to high flow fittings all around and a bad ass 3 satge filter system


thanks in advance

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Re: b;ack pipe or pvc for hardlines?

Post by baz » Wed Dec 02, 2015 12:16 am

If you do some research you will see that pvc is not recommended and in some places illegal for use as air lines.Too dangerous.
my question is why do yo need to run 170 psi . running your compressor at 170 is much harder on your pump and motor and also the compressor runs much hotter and creates a lot more condensation .

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duke46
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Re: b;ack pipe or pvc for hardlines?

Post by duke46 » Wed Dec 02, 2015 8:42 am

Black pipe will rust inside and you will be pulling it out very soon unless you have no moisture at all leaving your compressor. It works best for places that runs oil in their lines for the air tools. Copper is good but very costly.

I have used PVC for many years but only run 135 psi. 170 I would not want to do and is not necessary unless you are running air tools for heavy equipment use maybe? I switched all fittings in my shop to the high flow ones and all my air tools came alive. Even at 125 psi using that fitting my 1" impact tool is now usable :D

The new type air systems would be the way to go if you can swing the cost. They are so easy to add legs to and safe. Not sure what the max pressure is? The next key is buying the correct size for max air flow and then next thing is to make sure you have a line large enough for a blasting setup. It is the one that needs the most volume of air and CFM.

I would go with 1" as the main line and all the way to your blaster then drop like 1/2" lines down to feed every thing else.

If PVC is the only way for you to go then turn your pressure down and then box it in so it can not be hit with anything. The older it gets then it can become very hard and that is where the danger can come into play if something hits it. PVC is not app to blow on its on unless the pressure was way to high? When I installed all of mine in the 80's and have added to it a few times then it is easy to cut with the PVC ratchet cutters. The older it gets then if you need to cut then you have to use a saw or best to use a regular cutter for copper pipe. PVC I think is rated like a 360 psi but that is for liquid pressure and if I understand it right then it is diff than air pressure. I think I read that some dag where :?:

Best of luck to you and hope you make the correct choice.
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duke46
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Re: b;ack pipe or pvc for hardlines?

Post by duke46 » Wed Dec 02, 2015 8:43 am

https://www.google.com/search?q=garage+ ... C1AQsAQINQ" onclick="window.open(this.href);return false;
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Re: b;ack pipe or pvc for hardlines?

Post by WiseAssYT » Wed Dec 02, 2015 9:20 am

Like anything there is Good, better ,best .... That being said I've had close to 150' of black pipe for about 8yrs in my current barn and while I'm sure there is some rust internally , when I open the drops at the end of the runs anything and everything growing inside comes right out with the 100+psi of air blasting out , also have worked in shops with black pipe hardlines that are still in place 40-50yrs later no ones bitching or even thinking about changing them ...
I didn't even use my equipment for 1.5yrs after being hit on a motorcycle and my lines were fine
I use a 4 stage filtration system down to .005 for my powder coating and painting and have never found any chunks or even small amounts of rust on the first stage filter.

Buying quality filters that can handle HIGH cfm's of air is more important than the hard lines you choose , anything is better than using ridiculous amounts of 1/4" or 3/8" rubber hoses.

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Re: b;ack pipe or pvc for hardlines?

Post by duke46 » Wed Dec 02, 2015 1:07 pm

Yep rubber hoses for some reason will make there on moisture as I have found out on a 50' one that connects to my blast pot outside. So had to install something to get it before it hit the sand.

Like he said have the correct filters and controlling moisture is the biggest key for any pipe. If you live in a high humidity area then you will have even more of a fight on your hands. Auto drains are a must with my main compressor and then the drops are the next thing that need to be installed.

There is a lot more expense that you will have to pay out so get yourself ready for it.

There are also a lot of designs that can be used to also help with moisture and some work real well. Auto drains on them can help or just make sure you drain them often depending on usage. Air dryers are expensive but necessary at some locations and there are some good home made ones that are just using a fridge but not the freezer part of it.

There are a lot of little tricks that are used to help with moisture in your lines also.
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Re: b;ack pipe or pvc for hardlines?

Post by jtsmith » Fri Dec 04, 2015 4:38 pm

I have black pipe to my main filter regulator. From there it is 3/4 pvc but for safety I installed a pvc" union" with rubber gaskets. This will blow before the pvc does. I regulate it down to 125 PSI before the PVC. as @Duke stated, not many tools require air pressure this high.

Weird thing happened when I first built my oven. I had a shorted SSR which turned on my top 2 elements steady even thought the controller was turned off. When I returned to my garage I noticed something smelled hot. Inside temp was way over 750 and my wall was glowing red! Since the door of my oven was ajar, heat escaped and melted the 3/4 pvc running overhead, and with the air pressure this heated area became about 2.5" across, like a pvc blister.

I laugh now, but for this conversation, I want you guys to know my lines still held air and the line did not blow under 125 PSI

Several shops in my area use PVC for air lines. I can see how it could be dangerous if it did blow, but in my personal experience, it works ok.

As for all things though, it is your judgement call. I am only stating my experience. I feel safer with PVC than black pipe as I know the small run of black pipe I do have is changing inside more than the PVC is.

Have a clean out drop for each air outlet and use them. also have a clean out drop at the end of the line. You definitely do not want water in those lines in the winter time.
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overtimin
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Re: b;ack pipe or pvc for hardlines?

Post by overtimin » Tue Jan 05, 2016 8:10 pm

well I ended up going with the 3/4" rapid air kit and.... oh my god!! awesome kit!!! got it for 189.00 and the 100' was perfect for my med sized shop. came with everything I need and was an absolute piece of cake to install. I did the whole kit by my self in about 2 hours, hooked air to it and not one leak!!

very happy with the kit hands down good quality stuff. flow of all my tools is much stronger and you can feel the difference in volume

I ran the main line about 15' up the wall then all my drops where I needed them.


thanks for the help and tips guys.

I highly recommend the rapid air kit to anyone!!!!

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Re: b;ack pipe or pvc for hardlines?

Post by luv2fly » Wed Jan 06, 2016 7:24 pm

At the risk of being flamed, I run black pipe throughout the shop then - I ran PEX from my compressor (150 psi) to the filters/regulator. I also run PEX from the hard lines to the drop reels above my work bays. An engineer friend of mine ran some as an experiment 5 years ago and has had no issues. Nor have I. I believe it is rated for 125 PSI??
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Re: b;ack pipe or pvc for hardlines?

Post by melgross » Wed Jan 06, 2016 9:49 pm

NEVER use pvc for airlines. Pvc is only good for water. The problem is that air can explosively change pressure levels, and pvc doesn't like that. Some people are lucky with it, but it's very dangerous!

I ran a large commercial photo lab for many years, and we had hundreds of feet of air lines. We used copper, as that doesn't rust, and it's easy to cut and solder. But black pipe can be used, as long as your filter is very good, and any rust particles that get pushed down the line from the water, are removed.

And you will get water. If you aren't using an oil less compressor, you'll get plenty of oil too. The better the filters the less problems you will have.

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