What size and style air couplers?

[2CRUZ]

Hey Fellas
I am at the point in my compressor installation where I need to know what is the best size and style couplers to get. Should I get 1/4 or 3/8 what do most air tools use. Also what is the best size air line. I don't have a clue as to what I'm doing.

 

[Ben Buck]

" 2 ", most air hose is 3/8 inside diameter. As far as what most tools use in couplers and coupler bodies is up to the user. If this is for mostly home, hobby type use, you'll be okay in using 1/4, or M style couplers, available everywhere. Use teflon tape to seal the threads, and don't over tighten the fittings, you'll likely crack the tool casings. Good luck with your setup!!

 

[EOC_Jason]

^^^^ Most common good basic air line is 3/8" with 1/4" NPT ends. Most home / residential tools are also 1/4" NPT ends.

 

[Falcon67]

I haven't hit any limits around here using the regular 1/4"[ fittings. That includes painting whole cars.

 

[Bob C]

^^^ I agree!

 

[2CRUZ]

Are 3/8 hose 1/4 on the ends? So they will fit the 1/4 couplers?

 

[Bob C]

At almost any place you buy air hose, yes 3/8" hose has 1/4" ends. The only oddball place ive seen it with 3/8" ends is at the hobo freight store.

 

[WWIIjeep]

I haven't hit any limits around here using the regular 1/4"[ fittings. That includes painting whole cars.

Agreed, except for my 3/4" IR impact wrench and an old large air sander. Both run significantly better and faster with 3/8" couplings, so I've got a couple of coupler outlets and hoses set up that way. Everything else is 1/4" fittings.

 

[Bob C]

Agreed, except for my 3/4" IR impact wrench and an old large air sander. Both run significantly better and faster with 3/8" couplings, so I've got a couple of coupler outlets and hoses set up that way. Everything else is 1/4" fittings.

This a good spot to explain the difference between 1/4" / 3/8" standard flow and high flo.

Couplers and plugs are available in both pipe thread sizes. If you have standard flow couplers and plugs and you switch between 1/4" and 3/8" there is no difference in flow therefore no difference in performance because the hole size is the same. However, when you switch between standard flo and high flo, there can be a remarkable difference as the hole size in the couplers and plugs is larger. These high flo couplers and plugs are also available in both 1/4" and 3/8" pipe thread.

Sometimes these two facts get confused.

 

[WWIIjeep]

This a good spot to explain the difference between 1/4" / 3/8" standard flow and high flo.

Couplers and plugs are available in both pipe thread sizes. If you have standard flow couplers and plugs and you switch between 1/4" and 3/8" there is no difference in flow therefore no difference in performance because the hole size is the same. However, when you switch between standard flo and high flo, there can be a remarkable difference as the hole size in the couplers and plugs is larger. These high flo couplers and plugs are also available in both 1/4" and 3/8" pipe thread.

Sometimes these two facts get confused.

I'm assuming you're talking about the Asian and Global style high-flow couplings.

I was referring to Automotive Interchange couplings (also called Tru-Flate couplings). Here's the two sizes I was referring to:

3/8" (with 5/16" bore) on the left, 1/4" (with 3/16" bore) on the right.

Maybe I'm just a dinosaur but if so, so are we at work, where there's several hundred Automotive Interchange couplings still in use, so that's what I use at home too.

 

[Bob C]

No asian ****.

That pic shows what I was trying to explain. It is so much easier to explain it when I have all the couplers in my hands and showing the customer the differences.

We generally sell M style, A style, L style, T style, and P style. We also carry Big Flow couplers and plugs.

Your pic of the 3/8" with 5/16" bore is our P style couplers and plugs which are available in 1/4" and 3/8" pipe size.

 

[fflintstone]

I myself use the larger ID couplers, in Milton fittings it is an H coupler, Campbell hausfield it is an 3/8 I/M coupler. It is the same style as the common couplers, but has the potential to flow much more air.
They work better in my opinion. They are available with 1/4 , 3/8 male NPT ends and ¼ female NPT as well.
I have bought plenty of air tools that use all 3.

 

[WWIIjeep]

No asian ****.

That pic shows what I was trying to explain. It is so much easier to explain it when I have all the couplers in my hands and showing the customer the differences.

We generally sell M style, A style, L style, T style, and P style. We also carry Big Flow couplers and plugs.

Your pic of the 3/8" with 5/16" bore is our P style couplers and plugs which are available in 1/4" and 3/8" pipe size.

Cool. Maybe I can learn something (not always easy for a dinosaur).

The reason I posted the first photo showing 1/4" and 3/8" couplers was because I didn't understand this part of what you said:

If you have standard flow couplers and plugs and you switch between 1/4" and 3/8" there is no difference in flow therefore no difference in performance because the hole size is the same.

I'm guessing you meant the 3/8" couplers on 1/4" fittings, which is sometimes done, and doesn't help airflow, just as you said, but not what I was trying to show.

Anyway, I've never heard the couplings referred to by letter codes and I can't find them in the couple of industrial supply catalogs I looked in. The ones I'm most familiar with are "automotive interchange" (what you called type M, and sometimes called Tru-Flate) and "industrial interchange" (sometimes called Coilhose).

Can you explain or show photos of the M, A, L and T styles for comparison? Or whatever is commonly recommended?

Here's what we use:

From left to right:

1. Old-style Binks. Has a 1/4" bore, compared to the 3/16" bore of type M. We still use these in the paint booth (separate clean compressed air supply).

2. Industrial Interchange (Coilhose). What letter style are these?

3. 1/4" Automotive Interchange (Tru-Flate or Type M).

4. 3/8" Automotive Interchange.

 

[Bob C]

from left to right ... 1.) Don't know 2.) M style (Milton) 3.) T style (Tru-Flate) 4.) P style (original developer unknown to me)

Heres a chart for some of the styles. Keep in mind some styles are named differently by the company that sells them.

https://miltonindustries.com/COUPLER-PLUG_ID_CHART.html


Edit: I was trying to explain the difference between the M and P styles for flow and explain that both come in 1/4 and 3/8 thread.

 

[WWIIjeep]

Thanks very much for the chart, Bob. That, and your explanation helps a lot.

 

[Cryptic1911]

I use nothing but Milton V-style couplers. They have a very large opening, so they flow quite a bit more than most standard couplers. Model #'s 764,765, 760 and 761.

http://www.toolsource.com/vstyle-hiflow-brass-coupler-female-p-106755.html?osCsid=1qli7ep22tm0foa1gm7oc3j5n7

http://www.toolsource.com/vstyle-hiflow-brass-coupler-male-p-106756.html

http://www.toolsource.com/vstyle-hiflow-brass-plug-male-p-106753.html?osCsid=1qli7ep22tm0foa1gm7oc3j5n7

http://www.toolsource.com/vstyle-hiflow-brass-plug-female-p-106754.html?osCsid=1qli7ep22tm0foa1gm7oc3j5n7

 

[Falcon67]

Good chart. That also shows that most home compressors won't come close to maxing out a 1/4 fitting. I read a 3-4 PSI drop based on the output of my 60 gallon unit. FWIW - I picked up some 1/4" brass universal couplers at HD for $3 each this weekend. I was going to get some nice color coded ones at TSC but they had one checker and 14 people in line. So I went next door to HD.

 

[123Go]

"Good chart. That also shows that most home compressors won't come close to maxing out a 1/4 fitting. I read a 3-4 PSI drop based on the output of my 60 gallon unit. FWIW - I picked up some 1/4" brass universal couplers at HD for $3 each this weekend. I was going to get some nice color coded ones at TSC but they had one checker and 14 people in line. So I went next door to HD."

WOW' HD Chinese fittings, really? Whats wrong with our USA brands Falcon67?
FYI:
Why the larger I.D. fittings helps impacts/tools so much are because the first few seconds of burst pressure is what makes an impact gun work to break lose nuts. A larger I.D. fitting/hose allows more air "volume" witch helps the process along a great deal. Pressure/Volume/CFM are 3 different things, you cannot look at one measurement and call it a day.
They all work together and when this set of numbers are in check you wont even need your breaker bar anymore. Mines rusted to the cabinet wall in the corner. See links below you'll read many other guys know what a difference these fittings make too...Your time/money/ loss though~
Besides' just knowing my impact works better than yours makes me feel better anyways...lol

http://www.garagejournal.com/forum/showthread.php?t=94805

http://www.garagejournal.com/forum/showthread.php?t=28617&showall=1

 

[mrjaw14]

I have the hf 3/8" compressor shut off valve. Do you think that reduces flow very much?

 

[sberry]

Its unlikely the valve, a common ball valve hurts much. Its so short and the opening is as big as the hose you are using so its like adding a couple inches of hose?

For the first user set up, hook comp up, buy 25 ft of hose after a valve at the comp to a small filter regulator folloed by a 50 ft hose reel screwed to the regulator and one decent hi flow coupling you like on end of the hose, a box of plugs that fit the tools. Hang this all uyp, figure out what it does and where it goes, use it today and go from there adding a few convenience things or manifold sections as they occur.

I don't plumb my dream job to get started. For a single user/owner often 1 hose serves a whole garage. Leave a T on occasion to be able to continue. Its rare but still on occasion break back in to plumb something, its not the end of the world to take a fitting apart, that's why they invent the thread and the occasional union.

 

[LS6 Tommy]

I use nothing but Milton V-style couplers. They have a very large opening, so they flow quite a bit more than most standard couplers. Model #'s 764,765, 760 and 761.

X2. The 1/4" V couplers actually flow better than many other 3/8" couplers...

I have a 50' 3/8" hose reel by the roll up door for working under the car or airing up tires, etc. in the driveway, a 25' 3/8" reel at the back wall of the garage for working under the hood and a 20' 3/8" coil hose with an air gun on a tool reel above the bench. It's all fed by leftover 3/8" hose. My pressure drop is mostly noticeable at the end of the 50' reel, but changing to the V fittings made a big difference. I may switch over to 1/2" feeds this summer...

Tommy

 

[mineallmine]

I know this is an old post but thought I'd bump it back up for anyone else getting air lines plumbed into their garage and deciding on what style fittings to use and to also keep from starting a new thread.

On the advise and information I found here on garage journal (thanks again by the way) I just finished my compressor/air line install and was going to use my stockpile of "M" style fittings for all of my couplings. After reading this and doing some more research I decided to order a pile of the Milton "V" style couplings and all I can say is what a difference!!

I tried playing around with my old Husky brand 1/2" impact and tried to remove the lug nuts from my 64 Pontiac project that hasn't had the rims removed for over 9 years and has been outside covered for most of it and what would have been an issue before, they came off really easy. The air volume I can get with these fittings is impressive.

If you are upgrading or installing a compressor and air tools in your shop this is another recommendation for the "V" style fittings over the "M" style. They might be a little more money (minimal difference) and have to be ordered but well worth it.

The added advantage is that for low volume tools you can keep the "M" style coupling as it works with the female "V" coupling, just not the other way around.

 

[d.mcfarland]

Correct mineallmine, the V style is awesome and one of the best parts is that it has the lock open feature. Makes connecting/disconnecting super easy.

 

[Lelandwelds]

Ball valves are available with full port or reduced diameter operating valve ball guts. The price difference is minimal. 1/4 NPT is about the same size as 3/8 hose. They flow similiar volumes.

The difference comes in the quick disconnects you choke it down with. On other people's systems, I have used a mix of plain old Milton and Milton V style for the air hogs. Tools like blast cabinets are hooked up with pipe fittings and ball valves only. The hose for the V style quick connect is permanently tied to the air supply. ( no disconnect on wall end)

Pavement breakers and industrial tools can use the truly large hoses and fittings.

 

[nelstomlinson]

I have two wants for my couplers: high flow to minimize pressure drop, and easy to connectvand disconnect under pressure.

It sounds as if the Milton V connectors are great for the first; how are they for the second?

 

[sberry]

I started with H, they are big and come in 3 sizes of npt, 1/4 to 1/2 and with barbs 3/8 and 1/2. Rated at 74 for whatever that means. They are not easy to connect but I use them for bigger tools too, 1 connector both hose sizes.
If I didn't already have them would use a more modern easier coupler but I got a gob of stuff.

 

[firebirdparts]

I have only had one (relatively ordinary) item that could not work on 1/4" connectors. I have a Devilbiss finish line spray gun for base coat. No way will that thing run with 1/4" connectors. I had to remove all of them to spray with it. Quite the air hog. I was not sure why it wouldn't spray, so I put a gauge right on it. Mystery was solved.

 

[Schurkey]

I have two wants for my couplers: high flow to minimize pressure drop, and easy to connectvand disconnect under pressure.

It sounds as if the Milton V connectors are great for the first; how are they for the second?

Milton V are no treat to couple/uncouple. I'm not saying you need three men and a donkey, but boys and women will have trouble.

There was a guy on Garage Journal that was prototyping high-flow/easy-to-couple connectors; but I have no idea where that went in terms of production.

I like Oetiker couplers for ease of connect/disconnect; and I've heard really good things about Prevost couplers, but I've never used them.



All the photos that were posted in this thread seem to be missing. This is what I have to explain the differences in couplers. Milton "V", Milton "M" (Industrial Interchange) Milton "T" (Tru-Flate, Automotive Interchange) and Lincoln.