Air Couplers: HIGH FLOW low flow vs LOW FLOW low flow.
- Thread starter Stedlin
- Start date
Don1357
Well-known member
All this right after I bought 4 sets of the Kobalt high flow aluminum fittings.... 
In my defense I had a box of air fittings collected over the years and half of them did not like the other half, most were old and beaten up. I figure now that I'm finally setting up a permanent big compressor I would setup proper fittings. I particularly like the ease of coupling and removal of these guys.
By the way the pack with the quick disconnect and 3 couplers is selling for $4.98 at lowes, $13.44 at Amazon, and $11~$16 on Fleabay.
In my defense I had a box of air fittings collected over the years and half of them did not like the other half, most were old and beaten up. I figure now that I'm finally setting up a permanent big compressor I would setup proper fittings. I particularly like the ease of coupling and removal of these guys.
By the way the pack with the quick disconnect and 3 couplers is selling for $4.98 at lowes, $13.44 at Amazon, and $11~$16 on Fleabay.
All this right after I bought 4 sets of the Kobalt high flow aluminum fittings....
In my defense I had a box of air fittings collected over the years and half of them did not like the other half, most were old and beaten up. I figure now that I'm finally setting up a permanent big compressor I would setup proper fittings. I particularly like the ease of coupling and removal of these guys.
By the way the pack with the quick disconnect and 3 couplers is selling for $4.98 at lowes, $13.44 at Amazon, and $11~$16 on Fleabay.
I believe all of these aluminum HiFLo couplers are exactly the same internally. I have looked at six different brands and they are obviously identical. They are designed incorrectly as they attempt to allow use of other non HiFLo plugs even though they don't open the valve completely.
hangfirew8
Well-known member
I did the pressure drop tests with M type connectors and quick disconnects, back when I had a 10 gallon tank compressor.
One old and one new M type quick disconnects were highly restrictive. Several other old (decades old) quick disconnects were OK.
The new one was from Lowes.
Replacing everything from end to end with GuardAir high flows brought my IR impact from barely useful to a monster.
Before that, switching from motor oil to air tool oil brought it from useless to barely useful. With more air, though, I probably would not have noticed the difference.
-HF
One old and one new M type quick disconnects were highly restrictive. Several other old (decades old) quick disconnects were OK.
The new one was from Lowes.
Replacing everything from end to end with GuardAir high flows brought my IR impact from barely useful to a monster.
Before that, switching from motor oil to air tool oil brought it from useless to barely useful. With more air, though, I probably would not have noticed the difference.
-HF
This is a video I made to demonstrate one of the issues with some new HiFLo couplers.
M style plugs in HiFlo couplers
M style plugs in HiFlo couplers
bsaint
Well-known member
The hardest coupler ever for me to utilize is the Eaton 3RL.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
I have seen claims of "Twice the Flow" on packages of HiFlo couplers.
The large bore of the plug is usually pointed to as the reason for the increase.
It's only fair to point out that in my tests the 1/4" industrial plug that was used yielded "twice the flow" with one coupler as it did with another.
The brass standard coupler has a pressure drop of 16 PSI at a flowrate of 13 CFM while the same plug yielded only 15 PSI drop at a flowrate of 30 CFM. (OVER TWICE THE FLOW!)
The large bore of the plug is usually pointed to as the reason for the increase.
It's only fair to point out that in my tests the 1/4" industrial plug that was used yielded "twice the flow" with one coupler as it did with another.
The brass standard coupler has a pressure drop of 16 PSI at a flowrate of 13 CFM while the same plug yielded only 15 PSI drop at a flowrate of 30 CFM. (OVER TWICE THE FLOW!)
I'm seeing numbers here like 25 psi pressure drop for a 3/8" 50 foot hose but I'm plugging in numbers to the calculator on the Gates website and I'm coming nowhere close to that. Using numbers from my use case. I'm getting less than 1 psi drop 3/8" 50 foot hose at 8 cfm (gague pressure 135 psi)
What's accounting for that huge difference?
What's accounting for that huge difference?
sberry
Banned
You are only using 8 cfm,,, big difference from 25.
Looks like you're right. I just plugged in some higher flow numbers and the PSI loss per foot increases pretty quickly. I guess there are some advantages to not making much flow.
That said, considering how little I'm starting with, I'm interested in any and all ideas on eliminating choke points in the system which, at this point, is just a 50 foot 3/8 hose reel but will soon include another compressor in parallel and an overflow tank. It sounds like Stedlin's fittings are a good place to start.
That said, considering how little I'm starting with, I'm interested in any and all ideas on eliminating choke points in the system which, at this point, is just a 50 foot 3/8 hose reel but will soon include another compressor in parallel and an overflow tank. It sounds like Stedlin's fittings are a good place to start.
2ndGearRubber
Well-known member
I think this is worth quoting.
The average air setup people run simply isn't capable of delivering 90psi dynamic. That's why people get all bent out of shape about under performing impact tools especially. The industry testing pressure for rating output is nearly impossible to duplicate in the real world - which I feel is disingenuous at best. Even a shop running dual compressors with 80 gallon tanks at 125psi with no regulators can't deliver that to the tool. At least 50', sometimes 100'+, of iron piping to the bay, which I'm sure is totally free of rust. Then stepped down to 3/8 to enter the reel, through the reel, then 25' or 50' of hose, then another coupler.
I tried to run my IR2235 off an 30gallon air compressor at 150psi static, 50' hose. Pfffffttttt..... you could hear that the tool couldn't even properly spool up. It just rattled around and did nothing, it probably would have struggled with lug nuts.
You basically need to run 200psi static, and have a compressor capable of keeping up with the CFM, to get advertised performance out of an impact gun. 950ft/lbs "working torque", struggles with honda crank bolts. That's because for the "test", IR bolted the base of the gun straight into the compressor pressure vessel with a 1" long piece of tube.
Very true. This is also why many switched to the European HiFLo style couplers and plugs. My main point is that they probably didn't need to.
The common M style 1/4" industrial plug with 3/16 orifice is capable of supporting the flow requirements if used with a non restrictive coupler.
No need to switch out all your plugs and couplers to the European HiFLo style.
2ndGearRubber
Well-known member
Quick product question here:
I have your quiet plugs on lead hoses for my air hammers, very happy there. But my impacts have fittings straight into the tool, coupler is on the air hose.
If I use the Stedlin coupler, with a normal steel fitting connected straight into an impact, will it cause wear issues from vibration? I had an orbital with built in quiet plug on my impacting air ratchet, and found it wore when plugged into a normal steel/brass coupler.
Jswain
Well-known member
You should send your fittings to the guy doing all the torque tests on YouTube to see how it all compares at the end of a socket from a third party. Low-low / stedlin-low / stedlin-stedlin / high-high
vavet
Well-known member
I’m a test engineer, so I appreciate the efforts and documentation showing actual numbers. I have to wonder though...what’s the significance of this?
If I’m thinking of this right, then your tool should be able to do what it needs to do whether it has 150 or 95 psi on the upstream side of the coupler.
So what’s the right test? Do we need more of an air hog tool connected to see if the more restrictive couplers can keep up? Maybe a cut off tool or sander with a tachometer to see how the speed changes? Do we need an impact gun with a load on it?
I don’t have the answers. I’m just trying to keep the discussion going. I wish we had more of this type of stuff posted on GJ. I don’t want to Monday-morning quarterback the OP because I think he’s been forthcoming and responsive to the feedback provided so far.
If I’m thinking of this right, then your tool should be able to do what it needs to do whether it has 150 or 95 psi on the upstream side of the coupler.
So what’s the right test? Do we need more of an air hog tool connected to see if the more restrictive couplers can keep up? Maybe a cut off tool or sander with a tachometer to see how the speed changes? Do we need an impact gun with a load on it?
I don’t have the answers. I’m just trying to keep the discussion going. I wish we had more of this type of stuff posted on GJ. I don’t want to Monday-morning quarterback the OP because I think he’s been forthcoming and responsive to the feedback provided so far.
Just because I'm curious I ordered a Lincoln 815
This is by far the most restrictive coupler I've ever tested. Hard to connect as well.
I don't get it.
What I am attempting to convey with this thread is that "HiFLo" couplers and plugs are not necessary when used in conjunction with 3/8" air hoses.
The flow rate at 90 PSI to the free running impact is 30 CFM more or less. I checked this against an orifice plate. Obviously a free running impact consumes more air than when it is applying torque. A speed regulated cutoff tool uses more air when it is loaded but they both consume around 30 CFM or so maximum.
Earlier I demonstrated how one coupler can double the flow rate of the other using the same standard plug with 5 millimeter bore.
It seems obvious to me that users who switched to the HiFLo style couplers did so because they had been using couplers that were highly restrictive.
I was one of them and I know others.
Unfortunately these HiFlo couplers are not truly compatible with the common M,T and A styles.
Got curious about pressure drop of a 3/4" impact without using HiFLo couplers and plugs and ran a simple test.
Somewhat surprised at the results.
3/4" impact with two couplers and 25 foot 3/8" hose.
Somewhat surprised at the results.
3/4" impact with two couplers and 25 foot 3/8" hose.
22 PSI pressure drop through two M style couplers and plugs and a 25 foot long 3/8" hose while driving a 3/4" impact seems very low to me.
Could someone please suggest an air hog that is used with a 3/8" hose that I can test?
At this point I still don't get the need for HiFLo couplers.
Could someone please suggest an air hog that is used with a 3/8" hose that I can test?
At this point I still don't get the need for HiFLo couplers.
Jswain
Well-known member
Show us a number that = ft/lbs and let us decide for ourselves. You keep pushing pretty hard there is no need for high flow couplers well then prove it.
2x Milton v style couplers & 4 tool end plugs = $14
2x Stedlin couplers & 5 tool end plugs = $70
I understand they are easier to connect and quieter but to say there's no need for high flow plugs when they are literally the highest flowing 1/4 coupler at a fraction of the price seems silly.
Last edited:
What I keep harping on is that there is a huge variation in performance between couplers using the same standard plugs.
This has never been pointed out that I’m aware of.
What is silly is switching out all your plugs and couplers when you probably only needed to change couplers.
This has never been pointed out that I’m aware of.
What is silly is switching out all your plugs and couplers when you probably only needed to change couplers.
Jswain
Well-known member
But the plugs are the cheap part and will still give you a performance increase, perhaps not as big as the coupler but for the price it would be silly not to.
https://www.amazon.com/dp/B077Y7P9PW/?tag=atomicindus08-20
https://www.amazon.com/dp/B077Y7P9PW/?tag=atomicindus08-20
Jswain
Well-known member
But they work perfectly when used together. Which was my point, for $20 most people could outfit their whole shop
Go ahead and support the Chinese. I can't begin to compete on price alone which is why I take pride in producing better and more innovative products in the US.
On another note:
My dogs name is Milly.
I named her after Milton Industries because the President and CEO of Milton called me on my 70th birthday and wished me a happy birthday.
sberry
Banned
The 22# drop across the hose with the 3/4 gun was most certainly hose. Last time I used my 3/4 gun I didnt bother getting out the bigger hose, didnt seem to know the difference.
Jswain
Well-known member
I have no doubt that your fittings are made to a higher standard as they do like quite nice especially the orbital fittings!
Not that I am a COO snob as I rarely even look but I do appreciate the north american manufacturing.
In this test I discovered that a cheap coupler with one of my Stedlin Full FLow plugs has a similar flow to a Milton V with HiFLo plug.
I designed the Full FLow plug to be compatible with push to connect standard couplers such as the one shown in addition to our own. My intent was to offer a high flow alternative to those who want to continue to use their existing 1/4" industrial plugs and yet have high flow potential when needed.
I designed the Full FLow plug to be compatible with push to connect standard couplers such as the one shown in addition to our own. My intent was to offer a high flow alternative to those who want to continue to use their existing 1/4" industrial plugs and yet have high flow potential when needed.
Iron Beaver
Well-known member
- Joined
- May 3, 2020
- Messages
- 684
The biggest air hog I can think of is a 9" 4-5 HP air grinder. I have an old ATSCO unit that drinks compressed air like there's no tomorrow. After that, a 1" impact wrench.
Iron Beaver
Well-known member
- Joined
- May 3, 2020
- Messages
- 684
Ahhh sorry to be dense. I think your 3/4" impact wrench is the limit for what should be put on a 3/8" air hose and your search for greater air hogs might be in vain. I poked around on the IR website for a while and came up with nothing.
And no, I don't run the Atsco grinder on a 3/8" air hose. I run it on a 1" air hose with Chicago fittings all the way
And no, I don't run the Atsco grinder on a 3/8" air hose. I run it on a 1" air hose with Chicago fittings all the way
In this video I used the Lincoln plug that according to them is rated to 55 CFM as the restrictor.
As you can see, the performance of the no name push to connect coupler with Stedlin Full FLow plug is exactly the same as the HiFlo coupler and plug.
It's pretty darn close with a standard M style plug.
I don't know what the actual flowrate is but it is considerably higher than any air tool that I have requires.
This does bring up the question: What do you call an air coupler that has the same flow as a HiFlo coupler but does not support the European HiFlo large bore plug standard. (V style)?
Last edited:
Jswain
Well-known member
What brand was the red coupler that you used and how do you know it wasn't hi flow? Also wondering why you didn't show results of the same test with Stedlin coupler & plug
The brand is Wynnski I believe and it is not compatible with the large Euro 1/4" plugs. (V style) It accepts Aro, Truflate and M style 1/4" plugs only. The V plugs do not fit.
The reason I used that one was to show that the Stedlin Full FLow plug works on standard (Non HiFLo) push to connect couplers as well as the Stedlin Quick Couplers and yet yields high flow performance.
I would be more than happy to do the same comparison with the Stedlin Quick Coupler.
I decided to do a direct comparison between the V coupler and plug versus the Stedlin Quick Coupler with Full Flow plug.
Keep in mind that I don't know the flow rate. All I know is that it is obviously very high and higher than any air tool I have tried. I could determine the flow by measuring the pressure drop from the tank over time but the gauge I have on the tank isn't accurate enough.
THE TEST
Last edited:
I installed an accurate pressure gauge on the 60 gallon tank to determine the flow rate.
This is what I came up with.
Flow calc
Starting tank pressure 186
Ending pressure 135
Time .5 minutes
186 + 14.7 = 200.7 / 14.7 = 14.34 bar
135 + 14.7 = 149.7 / 14.7 = 10.18 bar
1 cubic foot = 7.48 gallons
60 gallon tank = 8.02 cubic feet
8.02*14.34= 115 cubic feet to start
8.02*10.18..= 81.64 cubic feet ending
115-81.64= 33.4 * 2 = 66.8 CFM
This is what I came up with.
Flow calc
Starting tank pressure 186
Ending pressure 135
Time .5 minutes
186 + 14.7 = 200.7 / 14.7 = 14.34 bar
135 + 14.7 = 149.7 / 14.7 = 10.18 bar
1 cubic foot = 7.48 gallons
60 gallon tank = 8.02 cubic feet
8.02*14.34= 115 cubic feet to start
8.02*10.18..= 81.64 cubic feet ending
115-81.64= 33.4 * 2 = 66.8 CFM
Last edited: