Air lines and NPT fittings.

by Zack A

I have a brand new 33 gallon Husky air compressor and want my tools to get the most out of it.

When I bought it I made the mistake of picking up the first 25' 3/8" rubber hose I saw. When I got home I and opened it up I realized that the 3/8" hose had 1/4" NPT fittings. I was pretty annoyed to discover the quick connect set I purchased also had 1/4" fittings.

I understand that pretty much all air tools have 1/4" fittings, but I wanted to maximize flow.

I immediately went online and purchased a 25' 1/2" rubber hose with 1/2" fittings, a couple 1/2" NPT quick couplers, the 1/2" plugs for the quick connects, and about $30 worth of 1/4" male x 1/2" male fittings that would allow me to use 1/2" plugs on the 1/4" tool inlets.

Lastly, I also replaced the standard 1/4" quick connect on the compressor with a 1/2" one. To be honest, I didn't noticed much of a performance difference, the tools just got louder.

My question is, did I just waste about $100? Was the 25' 3/8" hose with 1/4" fittings already large enough to prevent pressure drop?

My impact gun uses 5 cfm at 90 psi, and my compressor supposedly puts out 5.1 cfm at 90 psi. Just looking for some opinions. Any help appreciated!


Comments for Air lines and NPT fittings.

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Dec 17, 2015
Attaching air hose
by: Bill

A 25' hose isn't that long, and since your air tool has enough flow to operate properly, maybe it's not necessary?

Having said that, anytime you can remove any obstruction from an air line you improve the flow of compressed air and reduce pressure loss.

The question remains if it is worthwhile to do in your case. Only you can decide that.

Dec 16, 2015
by: Zack

Would it be better to directly connect the hose to the compressor outlet, by removing the coupler entirely? Or would I even notice a difference?

Thanks Bill!

Dec 15, 2015
Waste of money on air fittings?
by: Bill

No, I don't think you wasted your money on air hose and accessories Zack.

All of the detail about flow, plumbing and calculating pressure drop is covered on the pages of this site already.

Have a look at them and if you still have questions after, please add a comment.

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