Air Hose Size

[HaroRider]

Hey all, so I am curious what you guys think. I run my home shop with a 3/8" hose and mostly use 3/8" or 1/2" impacts when my Milwaukee has a hard time taking off a fastener or when it is dead.

I recently just picked up a 3/4" Earthquake. I have an extra 1/2" hose, should I switch everything over to 1/2" hose? Will this cause a negative effect on my tools since my tank is rather small? ~40 gallons. (Keep compressor running way too much?)

Or should I just keep everything 3/8? Will this greatly reduce the effectiveness of the 3/4" gun? Just trying to get some ideas on what to do.

I could just use the 1/2" hose only for the 3/4" gun but that may get annoying after awhile, even though I am only going to use it on occasion.

 

[The Cobbler]

I would use the 1/2 hose for the gun only. why wrestle with alarger hose when you don't need it

 

[sberry]

I got a lot of stuff, it's really rare I use a 3/4 gun.

 

[plinker]

Buy a 1/2" hose (look on ebay for a Speedaire branded Flexzilla, they were around 25$) and 3/8 body couplers/plugs for it. The make or buy a short 6'-10' whip hose that connects to the 1/2" hose so you can use your other air tools with it. Or have two hoses set up at the same time.

 

[HaroRider]

I got a lot of stuff, it's really rare I use a 3/4 gun.

Same here, I am only going to use it sometimes. I picked it up for $100 brand new.. so I figured why not.

 

[sberry]

Hook it up if you need it. I used mine once or twice last year for a minute.

 

[Kwikasfaki]

A 3/4" gun will need 1/2" hose. What size is your shop plumbing? You may need a dedicated 1/2" hose straight from your compressor.

 

[BlueBomber]

I have a 3/8" coupler on the end of my hose. I assembled a 3/8" male to 1/4" female adapter for all my other tools and take the adapter off when I need the larger fitting for my bigger impact gun. You could apply the same principle or a whip hose as said above.

 

[Packard V8]

Yes, general consensus is a 3/4" gun requires a 1/2" hose. That's if one is servicing big rigs, busting a hundred lugs more than 100' from a compressor.

No, the 1/2" is not an absolute must for general home shop use. I've run a 3/4" Earthquake successfully on 3/8" line. Once I took it to a friend's project and it operated on a short 1/4" line.

Bottom line - it depends on compressor pressure and volume, length of hose, diameter of smallest fitting in the system and what size/how many nuts one is busting.

It should also be noted OP has only a 40-gallon tank. How many applications before pressure drops and the diameter of the hose is immaterial?

jack vines

 

[Pontiac787]

For practical purposes would you see a noticeable difference in performance between a 25’ 3/8 hose and a 50’ 3/8 hose all other things being equal?

 

[sberry]

Absolutely if the volume is high enough. On a heavy 1/2 gun losses can be near a pound a foot. Have to run 140 to get 90 at the gun thru 50 ft of 3/8. This is why 2 stage is for running tools, so it can be turned up to contemplate for loss.
25 ft has 1/2 the loss of 50 and 1/2 has half the loss of 3/8 at these volumes, a bit over 20 cfm or so, I don't remember the exact math right now.
A 1/2 does help a 1/2 gun also,,, it's a matter of being suffecient. If it's working with 3/8 then it's working, but with single stage if it's not it can be helped with larger hose with marginal compressor.

 

[sberry]

This is a compelling reason to start with a better comp, don't have to fart with everything downstream forever to make up for loss, smaller piping and hoses can be used. Also makes up for long runs.

 

[Pontiac787]

Thanks. That’s good to know.

 

[theoldwizard1]

The real issue is, what is the pressure at the END OF THE HOSE when the tool is running ! The only way to know is make up a tee with a pressure gauge. Use the same quick connect (or threaded *******) and a whip to connect it to your gun.

It could be as simple as turning up the pressure at the regulator.

 

[sberry]

Yes, there is a lot of focus on the connectors, they only hurt a little. Main thing,,, is it working?

 

[Leveleer]

I just measured the pressure drop across a 25 foot long 3/8 diameter Flexilla hose.
At 30 SCFM the pressure drop is 18 PSI.
However, half of that is because of the long 1/4 bore in the 1/4 NPT end fittings.

 

[sberry]

How did you measure the cfm? That is a bit better than I thought it would be.

 

[Leveleer]

How did you measure the cfm? That is a bit better than I thought it would be.

Orifice plate method.
I had an extra hose of the same type with a stripped aluminum 1/4-18 fitting so I cut the fittings off both ends of the hose and replaced them with 5/8 compression fittings and tested this hose.
It tested at around 15 PSI drop vs 18 for the other hose.