Psi cfm npt rubber pvc poly 3/8 1/2

[Aviatordave]

Hey folks,

Have a question for the general assembly. I posted a topic not too long ago about what kind of material to plumb the shop with for the new compressor. It (the compressor) should have been here last week but HD seems to not know where it is. Hopefully this week.
In the mean time, I’ve been shopping hose reels. I want one in the center of the shop to hang from the ceiling so it’s right over my main project table. Plenty of reels to look at, think I’ve homed in on one. Now . . . I’m a pretty intelligent guy . . . Which only means that I’m aware of what I don’t know. Which is a lot. It occurred to me that I don’t know squat about air tool CFM requirements. The compressor that I’m hoping HD hasn’t lost is a DeWalt 80gal, 2stage, 175max psi, 17 cfm unit. (And it advertises that 17 cfm at 100psi. 17.9 cfm at 175 psi.) (Shop will be plumbed with 3/4” L copper.)
I plan on using more and more air tools as the needs arise. Air ratchet, die grinder, air hammer, sander, etc.
(I’m both a wood worker and a metal worker)
At some point I’ll probably be interested in a sand blasting cabinet and an HPLV gun. Who knows what else.

In my search for air hoses I see that 3/8” ID is the most popular size but 1/2” runs a close second. (Most of you can probably see my question coming now.)

Is 3/8” going to limit my overall cfm to a certain range of air tools and exclude some others that I know are more thirsty? (Ie. a paint gun) Or will I be ok? Should I go for 1/2”?

I also know that despite the ID of the hose, the couplings, quick connects, etc, are frequently 1/4” npt fittings so really that’s the weak link in the chain. Should I also be thinking about larger ID fittings (if they can be found?)

What has been your experience with air tools and cfm requirements with your own air systems? Let me hear the good, the bad and the ugly.

-Dave



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[sberry]

With 2 stage and 1/2 impacts 3/8 is standard. Don't fuss over the fittings, the modern ones are good. I happen to use type H,,, an old heavy duty flavor, comes in 3 thread and barb sizes. 1/4 thru 1/2 and all rated the same, 74 cfm. A 3/8 will drain a 5 hp comp blasting but a 1/2 doesn't hurt.
Paint is fine on 3/8. Only thing that needs 1/2 is larger 3/4 or inch air guns.
5 reels, 3 whips, all 3/8. I would brake out a piece of 1/2 if I actually needed it. Once or twice in the last year or 2 on heavy equipment with heavy air gun. Wait till you get a blast cab to plumb it with a size bigger hose. One of the main reasons you got a good comp is to have the headroom to use modest hoses. 1/4 is a different matter again. 3/8 is standard for this app.

 

[Aviatordave]

Thank you sberry! That is the kind of reassurance I was looking for!


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[strutaeng]

Just do a quick check with this calculator:

https://www.gates.com/resources/calculators/air-flow-calculator

Unless you are going over 100 feet using more than 20 CFM, 3/8" is more than adequate for shop pneumatic tools.

Just stay away from the 1/4" hoses meant for nail guns.

 

[36truck]

3/8 on everything but the blast cabinet. I would go 1/2 on that also if you were to use a 3/4 or 1" impact. Style of fitting doesn't really matter all are good.
I had a Ingersoll Rand 7.5 HP compressor ran everything in 1" black pipe with 3/8 hose one 1/2 hose for the big impacts. worked great. I painted a lot of equipment without an issue.

 

[rattle_snake]

3/8 hose is fine. If on a hose reel, the reel swivel will become the bottle neck. I ported mine to increase flow.

Use Milton 'V' connectors (or equivalent) instead of the common 'M'. They have a larger ID but can still bed used with 'M' male connectors. They make a big difference.

The other bottle neck is the regular/filter. Go 3/8 min for point-of-use, or larger if on the tank end and multiple users.
If you want full flow also have a drop or connection without a regulator.

Most important is a solid plan before you spend a pile of $