Worth going from 3/8" to 1/2" piping on compressor?

[skon1212]

I have a newer 60 Gallon craftsman that has a 3/8" outlet that I am setting up again in my garage. Before I just ran it as is to a filter then to my hose reel using a 3/8" whip hose and standard 3//8" fittings. I always had issues with water in my lines when running a sander or grinder on my car restoration. Now I am in a new house I want to set it up right. I want to use the set up like they sell on line using 1/2" pipe, so my plan is to use a 3/8" to 1/2" adapter to an elbow from the compressor to my whip hose which will then go to my piping set up. Eventually though it will reduce back down to 3/8" for my hose reel set up. What I am finding out is most iron or galvanized 90 elbows are only rated to 150psi unless they are brass and then the price is triple. I know some say not to mix brass an iron and some have said not to bother using 1/2"
if you are reducing back down to 3/8" at the hose. Just wanted to get some thoughts and maybe pics of how people are exiting their compressors. Last thing I want to do is blow up a fitting.
Thanks

 

[sandslot]

I did my new shop in plastic (name escapes me) line....it's what they use now in plumbing......always did black pipe but what a pain...plastic/nylon super easy to run and clamp on fittings....been few years and two very cold winters. ...HIGHLY recommended. Can share photos if needed....and very cost effective

 

[930dreamer]

OP, the most important issue is giving the hot air enough time to cool so the water can drop out.

sandslot,
Post some pics of your install.

 

[trentonmakes]

Pitch the pipe AWAY from compressor, 1in pitch per 10 feet


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[trentonmakes]

Re: Worth going from 3/8" to 1/2" piping on compressor?

Black pipe fittings are fine, I doubt you'll notice any difference with 1/2in TBH.
Come out compressor to a hydraulic hose, then to your pipe.
You'll want 25 feet before your tools for cooling.

Pitching the pipe and place traps like the pic should solve any water issues[emoji106]

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[sandslot]

OP, the most important issue is giving the hot air enough time to cool so the water can drop out.

sandslot,
Post some pics of your install.

I did my new shop in plastic (name escapes me) line....it's what they use now in plumbing......always did black pipe but what a pain...plastic/nylon super easy to run and clamp on fittings....been few years and two very cold winters. ...HIGHLY recommended. Can share photos if needed....and very cost effective

 

[sandslot]

Picture of the label ... It was PEX tubing

 

[94EG8]

I don't understand why the compressor outlet is so small. Any 60 gallon tank I ever saw had a 3/4" outlet. If the outlet is in the center of a large reducer I'd swap it out for something a bit larger. I ran 3/4 from the compressor right to the drops, it necks down to half at the water traps and then from there to 3/8 at the fitting. Larger pipe will help out with the water situation and more volume is never a bad thing.

I did my new shop in plastic (name escapes me) line....it's what they use now in plumbing......always did black pipe but what a pain...plastic/nylon super easy to run and clamp on fittings....been few years and two very cold winters. ...HIGHLY recommended. Can share photos if needed....and very cost effective

PEX is not rated for air, at all. It's for water pressure up to 160psi if I remember correctly and a third of that for air. I don't think it fails quite as catastrophically as PVC does but I still wouldn't recommend using it for a
air line.

 

[nmk_61802]

I have a newer 60 Gallon craftsman that has a 3/8" outlet that I am setting up again in my garage. Before I just ran it as is to a filter then to my hose reel using a 3/8" whip hose and standard 3//8" fittings. I always had issues with water in my lines when running a sander or grinder on my car restoration. Now I am in a new house I want to set it up right. I want to use the set up like they sell on line using 1/2" pipe, so my plan is to use a 3/8" to 1/2" adapter to an elbow from the compressor to my whip hose which will then go to my piping set up. Eventually though it will reduce back down to 3/8" for my hose reel set up. What I am finding out is most iron or galvanized 90 elbows are only rated to 150psi unless they are brass and then the price is triple. I know some say not to mix brass an iron and some have said not to bother using 1/2"
if you are reducing back down to 3/8" at the hose. Just wanted to get some thoughts and maybe pics of how people are exiting their compressors. Last thing I want to do is blow up a fitting.
Thanks

http://www.homedepot.com/p/Mueller-...e-Iron-90-FPT-x-FPT-Elbow-520-003HN/100184660

Class 150 - 500 psi

Use bushing and 3/8" close ******; close/ close with a reducer between or 3/8 close/ reducer and street el. to your liking at compressor. Use 1/2x1/4 bushing at drops and standard 1/4 mnpt quick couplings

 

[sandslot]

I don't understand why the compressor outlet is so small. Any 60 gallon tank I ever saw had a 3/4" outlet. If the outlet is in the center of a large reducer I'd swap it out for something a bit larger. I ran 3/4 from the compressor right to the drops, it necks down to half at the water traps and then from there to 3/8 at the fitting. Larger pipe will help out with the water situation and more volume is never a bad thing.



PEX is not rated for air, at all. It's for water pressure up to 160psi if I remember correctly and a third of that for air. I don't think it fails quite as catastrophically as PVC does but I still wouldn't recommend using it for a
air line.

I researched PEX for months....it has worked perfect for almost 3 years now including -20F temps....its just data....

 

[bigredmf]

There is pex tubing rated for air.

The label above is not

Red


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[skon1212]

Pitch the pipe AWAY from compressor, 1in pitch per 10 feet


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This is what I plan on using for my set up. Just not buying from that company as its about $55 in piping at Lowes or HD. I found a 3/8" male to 1/2" female brass coupler so I will probly use that into a 90 to my whip hose. Seems like 1/2" piping will definately help.
As far as the size of the outlet goes on the compressor there is a bushing but it looks like it's welded to the tank. I would replace it if I could.

 

[trentonmakes]

Do you already have the 3/8 pipe?
How long is your run?
How often will you be using air tools?
It you think the extra pipe size and cost is justified, go for it!

Personaly, I feel it's not going to be a great benefit, especially if you need to purchase all new pipe and don't have a high daily demand for air like a shop would have.



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[gungatim]

post a pic of the outlet. maybe we can tell if it can be modified. most I've seen can be unscrewed, or is a big 2" bung that can be drilled out and re-tapped with a 1/2NPT tap.

Remember, your flow is only as good as the smallest restriction, so 1/2 isn't going to help you much if your outlet is 3/8, same goes for the regulator. if you run 3/4" and 1/2" lines, but have a regulator off the tank that only has 3/8 (like many cheapo's do), it sorta defeats the purpose...

 

[Ironhorse74]

Pitch the pipe AWAY from compressor, 1in pitch per 10 feet


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What does pitch the pipe away from the compressor mean? Running up hill or down hill?

Brad

 

[trentonmakes]

If water is in the line, you want it to drain in your drop, not back to compressor or sitting in pipe.
Look at the pic, a couple posts back.

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[larry_g]

Two questions that will determine a lot of what you do;
1. What is the HP or delivery of the compressor?
2. What are you driving with the air?

If you have a 120volt compressor then 3/8 is more that enough.

If you are driving an airbrush small is OK. If your doing body and paint or a sandblast cabinet then 1/2" may be to small.

lg
no neat sig line

 

[skon1212]

Its a 60 gallon 220V that I plan on doing a car restoration with. The way I had it set up at my old house was. Compressor - Adapter- Ball valve- 2 foot whip hose 3/8"- To combination Water separator/pressure reg. (HF one) - Out to air hose. All told about 3 feet of run but no real piping.

I definitely need to figure out a way to get water out of my lines because running sanders and grinders for more than 10 min had water flying every where. I also plan on spraying primer when I get to that point on the car.

Here are a couple pics of the outlet. I measured the hole diameter and it says 5/8" from lip to lip but I am 90% sure it is a 3/8" threaded hole. Maybe you guys know different.

 

[trentonmakes]

You need a longer run!
3ft?,no wonder you had water lol

Wrap it around if you have too, but you want about 20 minimum before air hose.

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[skon1212]

You need a longer run!
3ft?,no wonder you had water lol

Wrap it around if you have too, but you want about 20 minimum before air hose.

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I did figure that after some research. That is why I am planning on starting with the setup that some one posted above. Still trying to figure out how to start it though.

 

[trentonmakes]

Re: Worth going from 3/8" to 1/2" piping on compressor?

Get that adapter with the thread size you want easy peasy japanesey
have your whip go to the pipe and have the pipe run 20 feet or so

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[nmk_61802]

Manual says 3/8"x2" bushing.

Also discussed before:

http://www.garagejournal.com/forum/showthread.php?t=118889

Just use a 3/8" close ****** and 1/2" elbow with a 1/2x3/8 bushing or a 1/2x3/8 reducing elbow

http://www.homedepot.com/p/LDR-Indu...0-Degree-Reducing-Elbow-310-RE-1238/100562561

as mentioned by me above

Not really worth changing the bushing out for the slight restriction if you ask me

 

[gungatim]

Its a 60 gallon 220V that I plan on doing a car restoration with. The way I had it set up at my old house was. Compressor - Adapter- Ball valve- 2 foot whip hose 3/8"- To combination Water separator/pressure reg. (HF one) - Out to air hose. All told about 3 feet of run but no real piping.

I definitely need to figure out a way to get water out of my lines because running sanders and grinders for more than 10 min had water flying every where. I also plan on spraying primer when I get to that point on the car.

Here are a couple pics of the outlet. I measured the hole diameter and it says 5/8" from lip to lip but I am 90% sure it is a 3/8" threaded hole. Maybe you guys know different.

thanks for posting the pic, that is what I expected it to look like. that is not welded, it is screwed into the bung, which is welded to the tank. it'll be tight, but you can unscrew that large fitting with the small hole with a big pipe wrench or socket if you have on that big. or as suggested, it can be drilled and re-tapped for a larger size if u want.

get a good water trap, or build a Franzinator (google it), they work extremely well. remember air is not oxygen, it is full of water, unless your humidity level is zero, you will always have moisture in the air, that will condense when it gets in the tank, or cools in lines...fact of physics, you just need to deal with it before it gets into the air tools. you can put an oiler on as well if you don't paint with it, helps coat everything, but I personally don't care for them...

 

[Keel]

I used 1" iron, extra volume, air tools use tons of air..

 

[94EG8]

That's a threaded bushing, it will come out, it may come out hard but it will come out. Remove it, replace it with one that reduces down to 3/4" Run a short 3/4" whip hose from the compressor to the the beginning of your pipe run (your local hydraulic shop can make the hose up for you, make sure one end has a free spin end on it) I'd run 3/4 from there to your drops, if you're just doing one drop run 3/4" all the way. I went from 1/2" to 3/4" and it made more of a difference than I expected. You can go to just 1/2" but for the time and money involved I'd just go straight to 3/4"

 

[RickP]

http://www.homedepot.com/p/Mueller-...e-Iron-90-FPT-x-FPT-Elbow-520-003HN/100184660

Class 150 - 500 psi

I don't think that Home Depot page is right about the working pressure. I'm pretty sure Class 150 fittings are rated for 150 psi working pressure (at 350 degrees F).

http://www.engineeringtoolbox.com/iron-threaded-fittings-d_855.html

But those fittings should be fine for the OP's compressor.

 

[skon1212]

I don't think that Home Depot page is right about the working pressure. I'm pretty sure Class 150 fittings are rated for 150 psi working pressure (at 350 degrees F).

http://www.engineeringtoolbox.com/iron-threaded-fittings-d_855.html

But those fittings should be fine for the OP's compressor.

Yep, that is what I though to. Some black iron fittings seem to be rated higher, but almost all the 90'S I saw were rated at 150 psi. I did find some brass elbows on Amazon though that were rated at 500psi. Even though 150 would work I would rather be safe than sorry.

 

[RickP]

Yep, that is what I though to. Some black iron fittings seem to be rated higher, but almost all the 90'S I saw were rated at 150 psi. I did find some brass elbows on Amazon though that were rated at 500psi. Even though 150 would work I would rather be safe than sorry.

Sounds good - that brass fitting should work well for you, especially at the outlet where the water and heat are highest. My compressor kicks off at 165 psi, so I installed my regulator as close as possible to the outlet and set it at 90 psi. I'm installing black pipe in the garage with Class 150 fittings, which are rated for 300 psi at room temperature. But I have one run of RapidAir tubing (150 psi wp) to get air to the basement, so the regulator allows me to dial the pressure to whatever level I want in the tubing.

 

[miner]

If water is in the line, you want it to drain in your drop, not back to compressor or sitting in pipe.
Look at the pic, a couple posts back.

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I disagree somewhat. I prefer water to drain to the tank. There will always be water forming in your tank anyway so that seem like the best place to have any water in your lines go as well. You can fit your tank with an automatic valve that opens for specified intervals once your compressor kicks on. This eliminates the vast majority of the water from your system and makes it so you have a lot less water collecting in your drops.

 

[94EG8]

I installed my regulator as close as possible to the outlet and set it at 90 psi.

If you're setting the regulator at 90psi you're not getting near enough air. You're likely only getting around 60psi at the tool.

 

[CNGsaves]

^ ^ ^ +1. Why have nice big compressor with capacity and immediately reduce it down with regulator for the entire airline system??

Keep your airline system at same pressure as upper PSI that you want compressor to run. This gives you more oooooompth out at end of airline system as you're not artificially restricting it. Rig up quick connect regulator that you move from drop to drop so you can manage PSI of whatever tool you are using that day at particular drop.

 

[Motofixxer]

Make your drops rise a foot or so from main line. Water runs down hill but has trouble going up. Have a drain valve at end of your line. So your main line pitches down to the line drain. In general less restrictions the better. Large supply then reduce at location.

 

[miner]

If you're setting the regulator at 90psi you're not getting near enough air. You're likely only getting around 60psi at the tool.

If a regulator is set at 90 psi then the entire system after the regulator will be at 90 psi no matter how far you are from the regulator. Are you thinking about airflow? When you operate a tool you WANT there to be a large pressure drop at the tool since this is what causes air to flow.

 

[RickP]

Re: Worth going from 3/8" to 1/2" piping on compressor?

If you're setting the regulator at 90psi you're not getting near enough air. You're likely only getting around 60psi at the tool.

I probably should have explained more - I keep it at 90 psi for average sanding/grinding and then crank it up for the impacts. My sanders are pretty cheap and it seems like they blow through too much air when I feed them with a full 90 psi - probably because the triggers aren't sensitive enough.

 

[RickP]

Re: Worth going from 3/8" to 1/2" piping on compressor?

^ ^ ^ +1. Why have nice big compressor with capacity and immediately reduce it down with regulator for the entire airline system??

Keep your airline system at same pressure as upper PSI that you want compressor to run. This gives you more oooooompth out at end of airline system as you're not artificially restricting it. Rig up quick connect regulator that you move from drop to drop so you can manage PSI of whatever tool you are using that day at particular drop.

It needs to be that way for me, because I've got a unique installation that's temporary. My regulator is in the garage and the RapidAir tubing feeds the basement, so I have no way to adjust the pressure in the basement. When I'm working in the garage, I can just crank up the pressure whenever I want, because the regulator is only 20 feet away. Someday I'll have a black pipe installation in the garage at full pressure and a second regulator/extra tank in the basement. But I'm nowhere near there yet...

For the OP, putting the regulator at the outlet will reduce the pressure in the pipes below 150 psi, which was his primary concern.

 

[SGKent]

I don't get it. I keep a 50' coil of 3/8 hose between the compressors and two water separators. If I am not watching the small one fills and spills into the larger one. I can run 100' of additional 3/8 line and still have plenty of air and pressure for anything I need. With two compressors they can keep up with anything I've thrown at them including constant glass beading with a commercial gun and pickup. I keep a small dryer at the very end to pick up any moisture left. Were I to paint I'd probably parallel some separators and add a commercial chiller type dryer. Now if multiple people were using air at the same time I could see where 3/8 would be a supply issue. I also drain the tanks after each use so the moisture in the tanks is expelled. Aphids near the outlets love it . So did the rat under the shed. He hit his head so hard the first time those valves opened I think he left a puddle as he headed to the neighbors....

 

[skon1212]

I got all my piping together but when I went to thread in a 3/8" black iron ****** into the bushing on the compressor it got tight real quick, maybe 2 turns or 6 threads. I didnt try and force it in because I didn't want to strip the threads. I tried a brass fitting that used to be in there and it went in fine. I then tried the black iron ****** in a black iron 90 fitting and it did the same thing, goes in a couple turns. Tried the brass fitting in the 90 and it went in nice and smooth. When looking at the threaded ends on all the ******, they look tapered so I can see why they would stick. Is that normal? I was just trying to mock things up before I use sealant and tighten things down. Also I have heard that you cant mix iron and brass, but then I see pics where people do it, plus I have to go black iron to brass for the ball valves. I posted a pic of the set up I am using again.

 

[matt_i]

The taper is gaged a little differently on the two fittings, leading to more threads engaged by hand on the one with a smaller gage diameter. If you have run a pipe threading machine like a Ridgid 535 you have to set this dimension up, there is a nominal setting on the die stock but you have to tweak it slightly from there.

I don't see a problem mixing black iron (steel) pipe and brass.

 

[skon1212]

So when it stops turning by hand, how much can I turn it past hand tight? I read somewhere you only go one turn past hand tight.

 

[sberry]

Turn it till its quite tight. You do not need to remove this big bush and upsize, the 3/8 port is what came with it and despite the common thought it was plenty as designed by the engineers who built it. Upsize to 1/2 steel line if you have it, even 3/8 pipe is good for a ways.
3/8 is kind of queer in this type of piping, 1/2 is so common and 1 size works good for the whole system.
Dont fuk with a bunch of drops, find a good spot to mount he filter reg and pipe to it with a simple drip leg ahead of it a little like the pic above.