frictional loss in airhose?

[Gregg Feldstone]

I have a small portable compressor for nailers and gen. shop use. 4.5 Gal, 4.3 CFM @100 psi, Max psi 125. 2 hp.
The store I got it from sold me 100ft of 1/4" air hose. They said it is all I will need for this compressor. The compressor manufacturer told me I could loose up to 25% of my pressure with this hose and cause my tools to run "slowly". They claimed it's from "frictional loss" with the narrower hose. Should I return it and get 3/8" or 1/2" hose?

[Jamie Buxton]

For running a nailer, frictional loss shouldn't be an issue. The amount of air moved by a nail being driven is really pretty tiny. However, if you're running something continously, like a sander, then frictional losses could be an issue.

[Joe Jensen]

100ft of 1/4" hose is a lot. If you use very little volume it would be ok, but you will be better off with 3/8" hose. I can't find the link but I was just reading on this topic in the past few weeks and someone had an air framing nailer on 100ft of 1/4" hose and didn't have enough power. This post linked to an article from an air hose manufacturer (maybe flexeel) and they said 25% pressure loss for 5cfm.

[Carroll Courtney]

If I was only using nailers then no problem,but if I was using a sprayer or air tools such as die grinders then you would have to move up.But a small compressor will run continuously using air tools(impact,grinders,drills)not because of the size of the hose but because not enought scfm's.---Carroll

[Will Overton]

Gregg,

Is your shop that big that you need 100ft hose? My 6 gal. compressor came with a 40ft hose that is more than plenty in the shop. On the rare occaision I want to use out in the yard, I bring the compressor with me.

[David Cefai]

There's a wealth of useful info here:

http://www.engineeringtoolbox.com/gas-air-systems-t_22.html

And what's more it is in Imperial Units

[John McClanahan]

Nailers have an air reservoir built into the handle, so a 1/4" should work. If it were me, I would return the 100' hose for 2 shorter hoses and quick couplers.

John

[Don Alexander]

1/4" hose works ok on roofing nailers, finish nailers , brad nailers and small guns like that

though 100' of 1/4" seems like it would be a mess most of the time framing nailers work much better on 3/8" hose

my experience has been that shorter hoses and couplers are much more managable that 1 long hose for almost any application i can think of

1 other thought........ if your primary use for it is in a shop then excess hose is annoying and potentially more dangerous (tripping hazard for 1)

i like to have enough hose to reach comfortably the place/s i need to use it and no more then have another hose setup with the proper coupler/s
for when i need more reach

[johnny means]

I have a small portable compressor for nailers and gen. shop use. 4.5 Gal, 4.3 CFM @100 psi, Max psi 125. 2 hp.
The store I got it from sold me 100ft of 1/4" air hose. They said it is all I will need for this compressor. The compressor manufacturer told me I could loose up to 25% of my pressure with this hose and cause my tools to run "slowly". They claimed it's from "frictional loss" with the narrower hose. Should I return it and get 3/8" or 1/2" hose?

What tools are running slowly? Frictional loss? I call hogwash on that one. If your tools are running slowly it is because they have depleted your air reserves in your tank and hose and your compressor isn't keeping pace with their consumption. A compressor of that size really isn't made for use with any tools that turn or spin. Actually, the longer hose is probably giving you a miniscule amount of extra run time due to the added air reserves.

[Rich Engelhardt]

Return the 100' hose and pick up some 25' ones or a 50' one.

100' of air hose is a major pain in the rump to deal with if you don't have to.

For runs over 25', I usually stick a 10 gal reserve tank at the end and run a 1/4" "whip end" off the reserve tank.

A 2HP 4.3CFM pump is nearly the same as I've been running w/the aux tank setup for over 15 years. It's never even been a hint of a problem.

I dial up the pressure at the regulator on the pump, and stick a second regulator on the off side of the aux tank.


On the rare occaision I want to use out in the yard, I bring the compressor with me.
Will,

W/the setup the OP has, that's probably not an option.
A lot of the 2HP class ( I say "class" because there's no way the motor is 2HP) machines have a heavy current draw under load.

My 2HP Ingersoll Rand can struggle at times to cycle if it's plugged into even a 10' 12 ga extension cord. It's plate says it's a 14.5 amp draw.

My 3.5 HP (which is actually only about half that - but - it's plate says it draws 15 amps) won't run at all on any time of extension - not even a three outlet 10 ga "pigtail".

This is actually a timely thread since my itty bitty 1 gal compressor started to give signs just yesterday that it's not much longer for this Earth.
I've been reading up on all the specs. of the small to mid size machines looking for a good replacement.

[Mike Cutler]

Greg

Flow in a closed system, be it pneumatic, or hydraulic, is equal to the square root of the differential pressure across an orifice restriction. The restriction in this case being the 1/4" hose connections and the hose itself. The diameter of the hose effects the flow by increasing or decreasing the Reynolds numbers ( friction losses).
Any fittings will only decrease flow, with 90 degree fittings being the worst.

A larger diameter hose with the minimum number of appropriately sized fittings will give you the best performance.

[Brian Cover]

1/4" hose would be ok for a brad nailer and if the hose is not more than 25' long. Exchange the hose for a couple of 3/8" hoses 25' and 50' long.

[John Coloccia]

3/8" hose. When I was running lots of air tools (drills, die grinders etc), I used 1/2" hose. Smaller hose will most certainly reduce flow and kill performance, though probably not for a little nail gun. There's a reason your water pipes are not 1/8".

[Gregg Feldstone]

Thanks for the advise. I should have said that I actually did buy two 50', 1/4" hoses with quick connects. I have opened one but the other is still in it's packaging. If they will not refund or exchange the opened 1/4" hose, would it be a mistake to occasionally attach it to a 50' , 3/8" hose for running my framing nailer outside the shop?

[Randal Stevenson]

Thanks for the advise. I should have said that I actually did buy two 50', 1/4" hoses with quick connects. I have opened one but the other is still in it's packaging. If they will not refund or exchange the opened 1/4" hose, would it be a mistake to occasionally attach it to a 50' , 3/8" hose for running my framing nailer outside the shop?

With quick disconnects, YES. Always use as short of hose as possible. In garages you see, fixed metal piping, which acts as a sort of second tank (with a short hose to the tool).

We had a roofer, that was hit in the face when he joined two hoses with quick disconnects. The compressor was on the ground, close to an outlet (shorter extension hose, longer air hose), and he caught it on some shrubs. They separated and it projected up toward him and hit him in the mouth. To connect two separate hoses, use a coupler, not a quick disconnect. If you HAVE to use a quick disconnect, you better make sure it is a zero pressure release model. (releases the air pressure before releasing the tool)

[Will Overton]

Gregg,

If it were me, and 50' is adequate for the shop, I'd keep one. If/when the time arises that you need 100', buy a 3/8" model. You may not use it often, but you won't be buying one very often, if ever again.