5 hp compressor air flow

[SpudHaulerTools]

Hi,
I have a 5 hp Campbell Hausfeld bought at CTC about 10 years ago. I believe it was the commercial cast iron version. Works well and has been lightly used. But would never sell because it's so handy.

My question; to increase flow and make use of a 3/8" air line, how do I insure the fittings, type M quick couplers, and valving will flow enough air to run my 1/2 air gun.

The air gun is also a CH and never seemed to have the power it should.

Hoping that I have restrictions in my lines due to flow.

running 100-125psi.

 

[p0lar]

Hi,
I have a 5 hp Campbell Hausfeld bought at CTC about 10 years ago. I believe it was the commercial cast iron version. Works well and has been lightly used. But would never sell because it's so handy.

My question; to increase flow and make use of a 3/8" air line, how do I insure the fittings, type M quick couplers, and valving will flow enough air to run my 1/2 air gun.

The air gun is also a CH and never seemed to have the power it should.

Hoping that I have restrictions in my lines due to flow.

running 100-125psi.

How long is the line you'll be using, and do you have a way to check pressure at the end? If you're using 3/8" lines with decent fittings, you should be fine. The Milton V-style fittings have massive openings compared to standard 1/4" NPT fittings.

As far as your air gun, is it an impact? If so, what model? Is it overrunning your compressor? Do you oil it regularly? There's just so many variables here to take into account.

 

[SpudHaulerTools]

The 3/8 line is 50' and my 1/4" line is the same.

It's the fittings I was concerned about, thinking that some quick connect don't flow as much as others.

I get full pressure at the end of the line, it's the flow that I want to be sure I'm getting that max.

Are all quick couplers rated for the same flow?

 

[firebox40dash5]

Are all quick couplers rated for the same flow?

No. Milton V's flow a whole lot more than standard Industrial/ARO/Lincoln types. They're rated for something like 75cfm, which IIRC is about double the rest.

And if you're using that 1/4" hose with the impact, stop. That alone will improve it a lot.

 

[AndyA]

No, all quick connects are not the same.

A cheap way to get there may be to plumb your 3/8" hose directly into the compressor tank (no quick connectors), then use only one quick connect at the end of the hose. This will give you only one restriction and may not hurt the flow that much.

I've run a 3/4" impact with 25ft of 1/2" hose and a "standard" milton quick connect. Distribution from the compressor is 1" black pipe. I may be loosing a little performance, but it worked well enough for the job.

You could also "cheat" and run your line pressure higher, then regulate it down near your impact. The higher pressure will push more flow through a small line. Yes you still lose a few psi, but if you're going to regulate it down anyway and have pressure to spare, it doesn't matter.

 

[zkling]

-Use 3/8" hose and make sure the ends have a good side through hole on them. I have seen a few manufactures use 3/8" hose then chock the ends down with small crimped fittings.

-Minimize the number of fittings and quick disconnects between the tank and the tool. If you don't need to take the hose off the tank, just thread it on directly. Can be a pain, but usually not an issue at a DIY, house shop.

-If you really wanted to get crzy with it, you could direct connect the hose to the tool and compressor, no disconnects. Would be a bit of a pain, but you would get max performance out of your setup.

-Could be an issue with the air tool itself. Which CH impact do you have?

What compressor is it? How big is the tank?

 

[TwoInch]

1. you impact may just be anemic as hell. i have used some CH impacts that were not wortha ****, and some that i would consider "useable".

2. use nothing smaller than a 3/8 line, with proper fittings. M types are totally sufficient, but there are better choices if you wanna go that route.

3. you mentioned that you have full PSI at the tool, but you are worried about flow. it doesnt work like that. in a static system, of course the psi will be the same all the way to the tool. the problem is as soon as you touch the trigger on the tool, the flow starts, and the PSI drops. it always will. you must try to minimize this drop with properly flowing lines and fittings. you say you are running 100-125psi, that 100psi at the tool drops immediately upon touching the trigger to 90psi or even lower. ive seen regulators limit flow seriously, to where 125psi on the reg would drop way below 90psi at the tool when in use. i personally run my regulator wide open, and i see almost zero drop while in use. if i turn the reg down to 115psi ill see a 10psi or more drop at the tool. YMMV just some things to think about.

use larger air line, your fittings are good, turn your regulator up to 125 at the minimum(135 may be better..) and possibly look into another impact that you know is good with ample power, and check it on your air system. report back with details

 

[crewchief888]

you may have several issues...

air line size
highly restrictive couplers
100-125 psi air pressure
the gun itself

i keep the regulator on my garage compressor wide open, compressor shuts off at 155psi, compressor in my service truck has no regulator, full pressure at 145psi.

every shop i've ever been at had no regulator at the compressor, full line pressure anywhere from 175-225 psi

 

[e-tek]

Rather than repeating whats been said 5x already......
It has everything to do with the cfm your compressor puts out. Big lines and high pressure are good, but mean nothing if the comp can't keep it up. I have 18.5cfm at 100psi, high by most standards, so my 25' 1/4 retractable lines don't bother my tools much. I can use my impact or sanders all day without losing performance.
That being said I just replaced my impact because it just got beat to hell over the years and lost performance.

 

[firebox40dash5]

Rather than repeating whats been said 5x already......
It has everything to do with the cfm your compressor puts out. Big lines and high pressure are good, but mean nothing if the comp can't keep it up. I have 18.5cfm at 100psi, high by most standards, so my 25' 1/4 retractable lines don't bother my tools much. I can use my impact or sanders all day without losing performance.
That being said I just replaced my impact because it just got beat to hell over the years and lost performance.

That's exactly the opposite of the truth.

You could have 30cfm at 150psi and a 120 gallon tank... run it through a 1/4" line with regular fittings and you'll starve a 1/4" air ratchet for air. Higher pressures do help overcome some restriction, but you can only go so high on that. So you need to start removing restrictions and let the air flow freely from tank to tool. I just got the shop switched over to Milton Type V this month, and that alone made a big difference over regular type M fittings. This week's project is to replace the haphazard **** plumbing we threw in when we moved to get up and running. We've been using a 1/4" ball valve (necked all the way down from 3/4" ) to 1/4" barb fittings with 3/8" hose, and a Sharpe air drier. That's getting replaced with Goodyear 1/2" hose with 1/2" fittings, only necking down to 3/8" at the outlet from the Sharpe.

If you're not using the regulator, or not going to (i.e. running it at max pressure anyway) then you might as well bypass that, too. No point leaving something that restrictive in place if you're not gonna use it.

 

[TwoInch]

Rather than repeating whats been said 5x already......
It has everything to do with the cfm your compressor puts out. Big lines and high pressure are good, but mean nothing if the comp can't keep it up. I have 18.5cfm at 100psi, high by most standards, so my 25' 1/4 retractable lines don't bother my tools much. I can use my impact or sanders all day without losing performance.
That being said I just replaced my impact because it just got beat to hell over the years and lost performance.

totally untrue.

SCFM of the compressor has nothing to do with tool performance wise. it only changes how long the compressor will run to fill the tank, and limit the amount of time the tool can be used in one blast. SCFM compressor ratings have absolutely nothing to do with the compressed air coming out of the output(regulator) on your compressor. its simply a measure of UNcompressed air flowing into the intake.

you can run air tools on air tanks that have no compressor attached to them. you can also run air tools off compressed nitrogen or CO2 cylinders... explain that one to me.

you were limiting your tool with 1/4" lines plain and simple. they are made for nail guns, and filling tires, not much else.

 

[Fixnair]

To test your setup install a pipe tee at the tool and put a gauge in the branch opening. Attach your hose to the tee opening, turn on the air and read static pressure. Now pull the trigger on your tool and see if there is an appreciable pressure drop.
If there is you can quantify it and begin removing restrictions recording each step 'till you can minimize. Almost all air tool performance is rated at 90 PSIG.

 

[e-tek]

That's exactly the opposite of the truth.

You could have 30cfm at 150psi and a 120 gallon tank... run it through a 1/4" line with regular fittings and you'll starve a 1/4" air ratchet for air.
.

totally untrue.

SCFM of the compressor has nothing to do with tool performance wise. it only changes how long the compressor will run to fill the tank, and limit the amount of time the tool can be used in one blast

Ahhh - which part of what I said are you having trouble with?

Don't worry boys, it's a somewhat difficult concept, but we can hep you sort it out...

Cubic Feet Per Minute is THE MEASURE of how much air GOES INTO of the compressor per minute - which is then directly RELATED (not equal) to how much goes out. If you have a low cfm through a 1/4" hose and a high cfm unit through a 1/4 " hose - which one is gonna run your tool better/faster/stronger? Tools are rated in cfm too, so if your compressor can't keep up to the tools rating, what does that tell you? My higher CFM compressor is going to pump more air, for a longer period, through any hose - and if the 1/4" hose carried enough volume, it'll run the tool properly - PERIOD.

you were limiting your tool with 1/4" lines plain and simple. they are made for nail guns, and filling tires, not much else.

OMG! For you to say 1/4" hose is only good for air nailers and filling tires is TOTALLY asinine - Number one, because a nailer and filling a tire are completely different! I have 1/4" hose retractable air lines for all my tools and BECAUSE of my higher cfm compressor, I get enough air continuously going through them to run HIGHER CFM tools - like paint guns, sanders and air hammers.

Any clearer yet?

 

[firebox40dash5]

Ahhh - which part of what I said are you having trouble with?

Don't worry boys, it's a somewhat difficult concept, but we can hep you sort it out...

Cubic Feet Per Minute is THE MEASURE of how much air GOES INTO of the compressor per minute - which is then directly RELATED (not equal) to how much goes out. If you have a low cfm through a 1/4" hose and a high cfm unit through a 1/4 " hose - which one is gonna run your tool better/faster/stronger? Tools are rated in cfm too, so if your compressor can't keep up to the tools rating, what does that tell you? My higher CFM compressor is going to pump more air, for a longer period, through any hose - and if the 1/4" hose carried enough volume, it'll run the tool properly - PERIOD.



OMG! For you to say 1/4" hose is only good for air nailers and filling tires is TOTALLY asinine - Number one, because a nailer and filling a tire are completely different! I have 1/4" hose retractable air lines for all my tools and BECAUSE of my higher cfm compressor, I get enough air continuously going through them to run HIGHER CFM tools - like paint guns, sanders and air hammers.

Any clearer yet?

I'm 100% clear that you are 110% wrong.

First, unless you're running a pump with no tank, you're forgetting that thing between the compressor outlet and the hose- the tank. There's some number of cubic feet at some pressure in there, and that's what runs tools. The pump is there to refill that tank. Yes, your compressor certainly can be the limiting factor in high-consumtion, high-duty-cycle use, but it's generally not. More likely the limiting factor is a series of bottlenecks between tank and tool, including hoses and couplers. How many CFM your compressor pump puts out has fuckall to do with how much air you can flow through a tiny 1/4" hose or a restrictive fitting at a given pressure.

If you'd like proof, send me a 1/4" hose with M type fittings. I'll run down a bolt with my 2135 with my 3/8" hose and V fittings, then switch to your 1/4" hose with smaller fittings and record it falling flat on its face trying to remove that same bolt... with 18cfm at 150psi behind it.

 

[firebox40dash5]

Here's an example if you're still not seeing it.

You're installing a compressor 50' from your breaker panel, and there's an existing run of 12ga wire from the panel to where you want it. It draws 40A at 120V or can be rewired and draw 20A at 240V. Of course, that 12ga wire is undersized for a 40A load at 120V. Now, your theory is that you can fix this by installing a larger main in your breaker panel. That may well be necessary if it's undersized, but it's just part of the problem. You can put in a 500A main, but that wire is still too small. The right answer is either A) run wire large enough to handle 40A at 120V for 50' or B) rewire the compressor to draw 20A at 240V. Why? Because the increased "pressure" (voltage) allows the wire to "flow" more, and decreases the "flow" (amps) of a given load, or the larger wire allows a greater "flow" at the same "pressure".

Example 2- a new apartment complex with 1,000 units is built 5 miles west if the interstate. The highway is 4 lanes each way, the exit for the road leading to this apartment is 2 lanes wide, but the road is still backed up every morning and evening because it's only one lane each way, and there's a traffic light every half mile. If you want to ease rush hour, are you going to widen the interstate or add another lane to the exit? Of course not. Unless you're Maryland DOT, because well, they're just dumb.

 

[TwoInch]

wow. i have a very clear understanding of how air flows through orifices. but you obviously dont believe, so here ya go, ill let the "pros" explain. scroll down to page 5 and 6, report back. http://www.reelcraft.com/pdfs/tech_bulletins/TB0001.pdf

 

[TwoInch]

another note, a 3/8"ID airline, with open ends, no couplers will flow about 48CFM free air at 125psi, your 1/4"ID with no couplings will flow about 17CFM free air at 125psi

all at 125psi
1/4"ID line at 25ft = 17cfm
3/8"ID line at 25ft = 48cfm
1/2"ID line at 25ft = 97cfm

 

[AndyA]

A bigger compressor feeding a big load through too small of a line just means your compressor cuts off earlier.

 

[SpudHaulerTools]

That's exactly the opposite of the truth.

You could have 30cfm at 150psi and a 120 gallon tank... run it through a 1/4" line with regular fittings and you'll starve a 1/4" air ratchet for air. Higher pressures do help overcome some restriction, but you can only go so high on that. So you need to start removing restrictions and let the air flow freely from tank to tool. I just got the shop switched over to Milton Type V this month, and that alone made a big difference over regular type M fittings. This week's project is to replace the haphazard **** plumbing we threw in when we moved to get up and running. We've been using a 1/4" ball valve (necked all the way down from 3/4" ) to 1/4" barb fittings with 3/8" hose, and a Sharpe air drier. That's getting replaced with Goodyear 1/2" hose with 1/2" fittings, only necking down to 3/8" at the outlet from the Sharpe.

If you're not using the regulator, or not going to (i.e. running it at max pressure anyway) then you might as well bypass that, too. No point leaving something that restrictive in place if you're not gonna use it.

That is my other question.

The Type M and Type V are not compatible? Don't fit each other?

Was hoping to leave the Type M on the 1/4" line and use Type V on the 3/8" line but still be able to use tools on either if needed.

Lots of good info.

Thank you.

 

[zkling]

Ahhh - which part of what I said are you having trouble with?

Don't worry boys, it's a somewhat difficult concept, but we can hep you sort it out...

You need to go educate yourself on fluid mechanics, then possibly compressible flow. Then and only then you can open your mouth on the subject, because now you are just giving out false information. Fox and McDonald's "Incroduction to Fluid Mechanics" Is kinda the standard text in the industry.

I don't know how many times we have gone through this on the forum.


Flow rate through a pipe = corssectional area x free stream velocity. (Q=V*A)

Velocity of the fluid is governed by the pressure differential between the inlet and the outlet. SO, for the same compressor (say 125psig tank pressure) discharging to atmospheric conditions (0 psig) the velocity would be the same. Good on this?

Finally for a fixed velocity, in order to increase flow rate one must increase the cross sectional area of the flow stream. Again (Q=V*A) In this case that would be the hose. So one can see that a larger hose would equate to a higher flow rate.


SpudHauler, what impact wrench do you have? I have a feeling this is more of an impact issues than a flow issue.

 

[TwoInch]

That is my other question.

The Type M and Type V are not compatible? Don't fit each other?

Was hoping to leave the Type M on the 1/4" line and use Type V on the 3/8" line but still be able to use tools on either if needed.

Lots of good info.

Thank you.

they are semi compatible. IIRC, the female V coupler will accept both V and M male ends. but the M coupler will not accept a V male end. someone correct this if its backward.

to get full flow of the V couplers, you need to have them all V style, male and female.

 

[firebox40dash5]

they are semi compatible. IIRC, the female V coupler will accept both V and M male ends. but the M coupler will not accept a V male end. someone correct this if its backward.

to get full flow of the V couplers, you need to have them all V style, male and female.

Correct. Heard some complain of leaking with V couplers and M *******, but mine don't... yet anyway.

Most of the gain looks to be from the much larger ****** orifice, doubt an M ****** with a V coupler would improve anything. I will say this- between the V fittings and finally fixing the compressor-to-wall plumbing with 1/2", the difference is incredible. My neat new 2145max finally sounds like it grew a pair, though I haven't had occasion to test it since.

 

[SpudHaulerTools]

CH 1/2 that I believe was a rebuilt.

My 3/8 SnapOn seems to have more power using the exact same lines.

Looks like some V style are in order.