Compressor Size vs. Impact Wrench Power

[tehfade]

So, I've been lurking for quite a while, and I've seen this discussed multiple times, but nobody has provided a clear answer.

I own an Ingersoll-Rand 2135 TiMAX. At one place I use it, it ran off an old tank of a compressor that had a 5hp/20A motor, a huge Ajax 2-stage pump, and a 60-gallon tank through T-type disconnects and 50 feet of hose. At the other place--my home shop--it's running off an Ingersoll-Rand Garage Mate, which is a 2hp 20-gallon model feeding 25 feet of hose and Milton V-type disconnects. Line pressure is 120 psi at both places. With the bigger compressor, it has much more power under ALL conditions. The smaller compressor cannot match it even with a full tank of air in it.

It makes sense to me that with the smaller compressor, I would not be able to run the impact for as long of a time because it will drain the smaller tank much faster and the weaker pump will take a while to fill it up. But why is it that I can't even get good power for the second or two at a time that it would take to get a bolt out?

 

[#1SomeGuy]

Are the fittings all the same size (from tank outlet to gun)? Hose the same size? It's all about flow, even tank pressure being equal it will drop if you can't flow as much air. Also your perception of it might change, were you taking apart two equally torqued identical fasteners?

You're correct that the pump and tank size will just come down to run and recovery time.

 

[TwoInch]

the only way it would be under powered is if you are getting a pressure drop when you pull the trigger. if you have a restriction, or different hose, you can get a pressure drop way below what the regulator is set to. you may have it set to 120psi, but your regulator may be a serious restriction, i have seen that many times. do you hear the regulator hiss, filling the hose, after you let of the gun trigger? if so, it is very restricitve, you should not really hear a hiss at all after you let off. if i set my regulator below 120 psi, it seriously restricts flow, so i run mine wide open with 135psi cut off, so i will have between 100-135psi at the tool depending on where its at in the cut in-out cycle.

the gun does not know if you have 10gallons of air, or 1000 gallons, as long as the flow and psi stay where they need to be, it will run exactly the same.

 

[Sureshot]

Put a tee in the line right at the tool and see what pressure you are getting while in use.

 

[JJThrasher]

Hose and fitting size and quality have a huge impact on performance. I use 3/8 instead of 1/4 fittings for this reason.

Sent from my SCH-I535 using Tapatalk 2

 

[Rico.]

^^^^ This is totally the money answer.

Not all regulators are created equal. I set mine at 120psi and I get a 20psi drop when
my impact is running. Definitely check the regulator.

 

[blacK20]

Your garagemate only has 1/4" coming out of the tank which is going to be your biggest bottleneck. As soon as you deplete the air in your 25' hose which probably takes half a second on the trigger, the tank is trying to catchup refilling the hose(which it cannot through the little 1/4" port) until you release the trigger. The bigger 60+ gallon compressors will usually have at least 1/2" ports coming out of the tank which will not have a problem out filling what your gun is releasing. < Not sure if that makes any sense.

 

[e-tek]

Your garagemate only has 1/4" coming out of the tank which is going to be your biggest bottleneck. As soon as you deplete the air in your 25' hose which probably takes half a second on the trigger, the tank is trying to catchup refilling the hose(which it cannot through the little 1/4" port) until you release the trigger. The bigger 60+ gallon compressors will usually have at least 1/2" ports coming out of the tank which will not have a problem out filling what your gun is releasing. < Not sure if that makes any sense.

Perfect sense. If it's not a welded 1/4" bung, change it out to a 3/8 or even 1/2". Run at least 3/8" to the tool, then see what it does.

 

[Fixnair]

When you guys ar using tools like impacts, die grinders, blow guns or air sanders why don't you come straight off the tank. Do not go through the regulator. It is a huge restriction unless it is like 1/2" pipe.
Put a gauge right t the tool to see if the pressure stays at least 90 PSI. If not remove the gauge and put it at the beginning of the hose and test again. Keep moving upstream 'till you find good pressure. The problem lies between the last two points.