Pneumatic quick release fittings

[jim gossage]

I am piping my shop for air coming from a 3 hp 30 galloncompressor and am looking for advice on the type of quick release fittings tobuy. This is a heated and dehumidified hobbyshop and I will mostly use air for blowing dust, spraying finish, and bradnailing. There are multiple styleconnectors (A, B, C, industrial, universal, ARO, etc) in various metals (alum,steel, brass) and of course endless brands. I have read that alum fitting wear out quickly, universal style fittingsare most likely to leak, and Campbell Hausfeld are poor quality. Otherwise, I haven’t found much useful infoon the net after about 90 min of searching. I am leaning toward inexpensive steel industrial fittings from the localBorg. Any advice from the pros?

[Mark Bolton]

Im a Parker Haniffin fan. Industrial style is by far the most common in the industry. Steel nipples, brass bodies. I like push to connect but not universal bodies. A good universal body is not any more prone to leak but they can be very hard to shove together. There have been several recent discussions about couplers here. I think one listed them as cupplers so you may try that in an archive search.

[Ed Labadie]

I've used the Milton "A" style for years......If you get the correct ones, there's no having to pull the collar back to insert the male end of the fitting, just push it in & go.

Ed

[Ronald Blue]

Parker E-Z-Mates are the cat's meow but cashy for the home shop. There regular fittings are good as are Milton brand. I am a fan of the lock back collar that snaps forward when the male fitting is installed. However not the style where the barrel of the coupler is spring loaded. To many times climbing over equipment and lowering an impact or other air tool down it caught and disconnected itself. The That's why I love the E-Z-Mate. You couple with 0 pressure and then the on-off ring locks the release collar so it can't disconnect. http://corpapps.parker.com/PMCSIMAGES/10057.JPGThe second brass style coupling is the one that I dislike. Accidental disconnects are a pain when you are 15 feet in the air on a piece of heavy equipment.


http://www.hydraulichouse.com/TOC/images/gif30.gif

[Rich Riddle]

I asked a similar question a while back and decided to go with the following recommendation:

http://www.hoses.co.uk/images/2013catalogue/p292.pdf

Knew someone with that setup and it far surpassed anything else, but to each his own.

[Mark Bolton]

To add to all of this, vitually any tool you buy that is supplied with a nipple it will likely always be the industrial. The bodies Ronald posted are by far the best however there are several less expensive options out there that are more than suitable for home hobby use. We have to be careful here insinuating that a home hobby shop should require $200 combination squares, 500 dollar levels, and 40$ quick disconnects ;-)

Soon hobby woodworking will look like venturing into some financially unattainable hobby to anyone who reads this site hah.

Your home center couplers are likely on 85 percent of the air hoses around the country and will likely serve you well. But the parker style sure are nice. I wouldnt do without at least push to connect personally.

[John Huds0n]

Take a look at these from Amazon. Fairly inexpensive and they have good reviews. I ended up buying three sets - which I believe is about the cost of ONE E-Z-Mate, and I have been very happy with them

http://www.amazon.com/gp/product/B003TFE7WK/ref=wms_ohs_product?ie=UTF8&psc=1

[Jim Andrew]

John H, that looks like a good deal. Just remember that these wear out, so you need to keep some extras on hand.

[John Huds0n]

Yes - I should point out that the actual fittings are aluminum, so over time I would expect some wear - but at this price point and for normal 'home use' they should last for quite a while

I used to use the Borg fittings and had to shut off my main air line at night due to some leaks (nothing like hearing your compressor cycle at 2 AM). I have had these fittings for about 9 months now and everything has remained air tight

[Lee Reep]

My favorites I bought 10+ years ago. DeVilbiss brand, and likely rebranded fitting from some other manufacturer. No need to pull collar to insert (I guess this is referred to as "press to connect").

By all means do not buy Harbor Freight fittings. I worked for awhile at a shop that bought HF stuff. I broke two quick disconnects while there when they hit the floor when a hose was dropped. Brass shattered and parts went flying. Also, the HF "premium" rubber air hoses developed bubbles in several spots after about a month. You get exactly the quality you pay for at HF -- not much.

Finally, I solved all my leaking connection issues by going to Teflon pipe compound instead of using Teflon tape.

[jim gossage]

I've used the Milton "A" style for years......If you get the correct ones, there's no having to pull the collar back to insert the male end of the fitting, just push it in & go.

Ed

I like the look of the Milton's and they have a good reputation. It's a little hard to tell from the catalog which fittings are push to connect. Do you know off hand? I was looking at the M/I style connectors but they don't look like they are PTC. The Parker's look great, but at $30 per fitting I'll enjoy a few extra bottles of wine instead (not while running my tools, of course).

[CPeter James]

40 years ago, I was tired of dealing with leaky, hard to use fittings and a contractor friend suggested "Lincoln type L" fittings. I have been happy with them. They insert without having to pull the collar back manually, are not leak prone and very rugged.

CPeter

[Ed Labadie]

I like the look of the Milton's and they have a good reputation. It's a little hard to tell from the catalog which fittings are push to connect. Do you know off hand? I was looking at the M/I style connectors but they don't look like they are PTC. The Parker's look great, but at $30 per fitting I'll enjoy a few extra bottles of wine instead (not while running my tools, of course).

http://www.amazon.com/Milton-S776-Style-Coupler-Mal/dp/B000COTXHU/ref=sr_1_39?s=hi&ie=UTF8&qid=1393079715&sr=1-39&keywords=milton+a+style

Is the one I use. #775 female or #776 male. Page 8 of the Milton pdf catalog.

I usually get mine from the local CarQuest store.

https://www.miltonindustries.com/uploads/Milton_Catalog_August_2011.pdf

Ed

[John R Hoppe]

First, I want to say that I work as a distribution manager for a Prevost USA, company that makes high precision disconnects and other products for compressed air. You can see some of our product here http://www.prevostusa.com/. I work with both manufacturers and end users every day to provide them with better solutions for their compressed air management, and I see all sorts of problems, issues, etc.

There are really only 4 common interchange profiles in use in the US today, and one relic oddball. They are the ISO 6150B or Industrial profile (Milton “M”), the Truflate profile (Milton “T”), the ARO 210 profile (Milton “A”), and the European 7.2mm High Flow (Milton “V”). The odd one out is the Lincoln “long nose” profile. Stay away from the universal couplers as they are prone to develop leakage in use.

To select the type of profile for your shop, you need to consider the following:



How much air flow do you need?
Durability and resistance to leakage.
Ease of use?
Cost of the system


For air flow, the coupling system needs to be rated according to a standard parameter set. Normally 100 PSI applied, with the flow in CFM rated at 10 PSI drop across the coupler/plug. The high flow design is best, flowing about 70 CFM, Industrial profile and Truflate next at about 32 CFM, and ARO 210 at about 28 CFM. The Lincoln profile will flow about 22 CFM at best.

For durability you need to look at the plug materials and the internal seals in the coupler. Plugs need to be hard and resistant to deformation when dropped. They need to be made of steel and should not scratch when a file is pushed across the end. Prevost plugs and some others are made of hardened steel. Aluminum and brass plugs deform easily and will damage the seals inside the couplers, and should not be considered in most instances. The couplers need to utilize an o-ring seal that seats on the barrel of the plug. Many inexpensive couplers use a flat gasket that is prone to leaks.

In operation, most couplers use a spring loaded locking sleeve that needs to be retracted then pushed forward to lock the plug in place, often a two hand operation, and this can be difficult with air pressure applied. Some couplers are “push to connect” operation but still use a sleeve to disconnect. Sleeve couplers are notorious for popping off when dropped or slid across the floor. The Prevost coupler design is always “push to connect” and uses a push button to release.

If you are looking for the lowest cost in the system, and do not mind that compre$$or running in the back of the shop, by all means get the cheapest coupler system available. If you want a precision coupler that will perform over time and hold the air seal dependably, you will need to purchase accordingly. A good quality precision coupler will set you back from $18 to $30, depending on the style and functionality.

Last, but very important, is a safety design for releasing air to prevent hose whip. This design of coupler will release all downstream pressure before the plug is allowed to come free. Some designs for this use a “twist/turn/push/pull” combination of operations to do this. Prevost invented the push button operation, originally with a two press sequence, first to release the air and second to release the plug. This design has since been copied and is being made in China. The new Prevost safety couplers offer a single push operation that both bleeds off downstream air and subsequently releases the plug when the pressure is gone. It is fast, efficient, and safe, all in one.

In closing, do your homework and explore the options available. Prevost, Milton and others make fine quality couplers and can take care of your needs.

[Bill Neely]

John,

Thank you for the informative post. I use the Milton T style now but am thinking that I may switch to the Milton V for my finishing equipment.

Bill

[Charles Lent]

Whatever you do, stick with one manufacturer and style. I found out the hard way that mixing brands, even though the fittings were visually identical, gave me problems. I now buy only one type from only one source.

Charley

[Mark Wooden]

I've been using the ype M for 30 or more years with no complaints as long as you use a good brand of fitting. Cheapies don't last and almost always leak. The type M is the most widely used in this area too, making it easy to 'borrow' air on site.

[jim gossage]

So I ended up buying Milton type A fittings. They are push to connect, steel, look sturdy, and provide a good solid fit between coupler and plug. However, I have a leak between a female coupler and the male 1/4" NPT fitting on the hose. I brushed Oatey great white pipe joint compound on the male threads and tightened the joint moderately, but had an obvious leak. I then took the joint apart, put a heavy coat of joint compound on, and tightened the joint almost as tight as possible just using wrenches. The leak is much better but still detectable with soap suds. Not sure what I'm doing wrong here so any thoughts would be appreciated. Do I need to wait several days for the joint compound to cure? Do I need to torque the joint as tight as is humanly possible? Is it a bad coupler or pipe fitting? Thanks.

[Jim Andrew]

My new rapid air system instructions say to put 2 wraps of the teflon tape on your fittings, and then use the pipe dope. Could be a bad thread, most of that stuff is chinese made now, and they turn out some reject parts.

[jim gossage]

Thanks Jim. I'm slowly figuring this out. I bought some heavy duty Teflon tape (gray in color, and perhaps 2-3x as thick as the normal white stuff), and put 2-3 wraps around the male joint and then tightened it moderately. That seems to work pretty consistently for an airtight leak. However, now I'm having problems with the barbed fittings for hoses. I'm using a 3/8 fitting for a 3/8" ID rubber air hose. The barb goes in a little easier than I expected, but does take a little force to pull out. I then tighten a small wormgear clamp on the fitting until rubber starts to protrude through the worm gear slots. And sometimes that's not tight enough to prevent a slight leak. Any trick to this that I'm missing? Do I need to wrap some Teflon tape onto the barbed fitting?283755

[Mark Bolton]

One thing you may want to look into is Oetiker style clamps and an inexpensive crimping tool. Worm clamps are just too clunky for my taste but you may not mind them. They will clean up the ends of your hoses if you have to assemble them in house.

An even better option is to find a local hydraulics shop and have them crimp standard brass ferrules on the ends for you. Its worth a few bucks.

There is no need for tape on the barb.

[Jeff Monson]

We use Milton "m" at work. They are very inexpensive and work well, I dont think any Milton style will serve you wrong. FWIW, the aluminum ends do wear out, but in a hobby shop it will take awhile.

[Jeff Monson]

One thing you may want to look into is Oetiker style clamps and an inexpensive crimping tool.




I'd second that advice. If you choose to stick with a screw type clamp, find some fuel injection hose clamps, they clamp more evenly and dont dig into the hose. You can wrap the clamps in electrical tape or heat shrink to make them a little less grabby.

[glenn bradley]

A no-go feature for me is a collar that is not protected from impact release. The type that have a solid ring protecting the collar mechanism don't pop loose when you drag them or bump them against something. Beyond that I am pretty open.

No.283768 Yes.283767