Compressor Output Question...

[Derek Arita]

So...if I have a 2 stage compressor, with a 1/4" output fitting, can I use 3/8" ID hose and fittings? I'm looking at a 2 stage, 10.7 cfm compressor that also comes with a 1/4" out fitting and was confused, as I would think that high an output would have a 3/8" out.

[Mike Cutler]

Yes, you can use a 3/8" ID hose and fittings. I use 3/8" fittings with 1/2" hose, at my regulator output.
A 1/4" NPT pipe fitting orifice would have absolutely no problems passing >11CFM. My Compressor is 17CFM and a little air blow nozzle, with a 1/4" fitting ,and a < 1/8" aperture opening, can overcome my compressor's ability to keep up.
I've been running a nail gun on my roof this past week. There's 150' of 1/2" hose between the regulator output and the gun on the roof. I use 1/2" to keep the CFM ,up and pressure losses to minimum at the gun between strokes. There's 130' of 3/4" pipe and hose between my receiver tank and the regulator inlet.

[Tom M King]

Do you mean it has a 1/4" regulator on it? The tanks usually have bushings that reduce the size from the threaded opening in the tank, on larger tanks, which I would think a 2-stage pump would be on, so the bushing could be easily changed.

One of my 2-stage compressors is a pump which is normally on 5hp compressors, but I have that one slowed down for a 3hp motor, to run on temporary services. I run a 3/8" regulator setup on that one. I expect a 1/4" would allow that much air through, but I sometimes run a couple of hundred feet of hose, so I don't want any more restrictions than necessary towards the supply end.

If yours already has a 1/4" regulator, I'd try it to see if it will do what you need before replacing it.

edited to add: all my quick connects, on everything, are H style 3/8".

[Derek Arita]

The compressor has a built in regulator. The output of the regulator is 1/4". I'm working on a blast cabinet. An expert on the cabinet I have, advises use of 3/8 minimum to the regulator at the cabinet. I'm a real dummy when it comes to compressors and such.

[Tom M King]

??? Maybe just under a shroud? I've never seen one you couldn't change. Yes, more air is better for a blast cabinet.

[Tom Bender]

It depends on how much air your cabinet requires. If 11 cfm is enough then your regulator is big enough. 1/4" hose would be marginal, you should use 3/8" hose. Bigger than 3/8" os a waste of material but if you have some 1" hose available it will work fine also. However my guess is that you will need much more than 11 cfm.

[Ken Combs]

The CFM for blasting is driven by the nozzle size. I use a 3/32 nozzle most, 1/8" some and a 1/4" hose will work with the smaller, 3/8 with the larger. Nozzle size is determined by the blast media.