Not All Quick Disconnects Are Equal

Quick disconnect pneumatic fittings have been a staple in any manufacturing facility I have ever visited in my 10+ years as part of the manufacturing world.   The fact is, they have been around for a lot longer than 10 years.   The style we see most often is the 1/4″ Quick Disconnect Fitting, and we are typically troubleshooting a lack of air volume problem because they are not sized properly for the application.  These can be found in any industrial supply companies catalog, your local hardware stores, and even auto parts stores.   Quick Disconnects are even sold with certain EXAIR Industrial Housekeeping products, the key being they are properly sized.

Properly sizing the quick disconnect is a critical step in the process of deciding how to lay out your piping system as well as how to ensure products operate at optimal performance.  As you can see in the picture above, the two quick disconnects on the left are both larger quick disconnects as well as larger NPT thread sizes.   The two on the right are smaller and probably a bit more common to see.  Also notice the thread sizes on each, these are also manufactured in many other NPT thread options.   The through hole on the quick disconnects is decided by the size of the QD, not the thread size on the other end.   The example I am illustrating is comparing the 3/8 NPT and 1/4 NPT quick disconnects: Even though you can have 3/8 NPT threads, your throat diameter of the QD is still restricted to .195″ I.D., the same as the 1/4 NPT.  This can be a large restriction on a product with a 3/8 NPT thread size.

The Inner Diameters of the Quick Disconnects

Also to be noted is that all QD’s of the same size are not made equally, tests have shown that you can lose as much as 20 psi through a quick disconnect and up to 40 psi when not properly matched with the female QD.   This leads to the next step which is to ensure that you are not purchasing a QD on appearance.  MAke sure to choose the QD designed to permit the amount of air you need to operate your point of use product without a volume or pressure loss.

These two points are reasons why quick disconnects can diminish your point of use compressed air product performance.  If you have questions on which size to use with your EXAIR product or need help determining why your point of use product is not performing how you would like, contact us.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

Not All Suppliers Are The Same

Just last week I received a package on my front porch.  This was a replacement part for a tool which I purchased used, knowing it needed the part.  The trick is, I needed it a few months ago.  I ordered the part from the manufacturer directly on July 2, 2015.  This part was said to be in stock and would ship to my home from their location which was also in the United States.  I heard good things about the company and I bought the tool with confidence I could have the part and the tool fixed quickly. I thought, no big deal I will get it within a week, fix it, and then use it.

After not receiving a shipping notification and nothing showing up at my door for two weeks I decided to call the company.  I finally got hold of a customer service representative after I had to wade through the automated phone attendant.  The person explained that they had in fact received my order and they would try to ship it out the next day so watch my email.   Well, the next day came and when it was nearing the end of the day I decided to call in again since I had still yet to receive a shipping confirmation.  This time I got in touch with a different customer service rep who explained there had been a fire in their warehouse and that nothing was shipping that day or even that week.   The fire didn’t happen that day, it had happened over 2 weeks prior to that.   Instead of notifying me when I placed my order, or even when I called in the first time I was simply told incorrect information.   I gave them the benefit of the doubt and after discussing the issue the customer rep. told me they are doing their best to get items lined up and out as quickly as they can.  It should only be a few more weeks.

I accepted the explanation and began the waiting period.  a few weeks came and I received a back-order notification in the mail, still no notification of any sort stating they are not shipping any products out.  Few more weeks and another post card.   After the third post card I had almost forgotten about it.  Finally I received an e mail, my item had shipped.  Two days later it was on my porch and packed like any other shipment.  No explanation for the delay, no apologies, and as if it was just normal business for them.

I ordered the part on July 2nd,   I received the part on October 13th.  Needless to say, the quality is good but the customer service communication is fairly lacking.

I began to think about what we do at EXAIR, and came to the realization that if something like this had happened here we would have sent out an E-News, a simple e-mail, tell customers who call in, and other forms of communication to every last customer that had an order in and we would be notifying every customer that was placing new orders.  We would be up front with the information and we would not hesitate to apologize for the inconvenience.   We have had disruptive incidents in the past which we handled this way, this is just good business etiquette.  This goes hand in hand with the fact you speak to a human when you call in to our office, all stock products (and we stock it ALL) ship same day on orders received by 3 PM ET when shipping in the US, and we will give you updates via e-mail or phone however you prefer.   Then to top it all off, we will give you a 30 day guarantee and a 5 year built to last warranty on pneumatic parts.

30 Day Guarantee
30 Day Guarantee

So if you want to be informed, treated right, get the products you need in a timely manner, and get your problem solved, you have zero reason to go with anyone else.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

Quick Disconnects & Why Not To Use Them

Quick Disconnects are a quick and easy solution to hook up devices to your compressed air system.  These units can be found in quite a few factories and are more often than not being used incorrectly.  I know that on the air compressor in my garage, the only way to hook anything up to it was to use 1/4″ quick disconnects.  Chances are they are even a few of them within your facility, assuming you have compressed air available.

1/4" Quick Disconnect male and female.
1/4″ Quick Disconnect male and female.

When you really look at a quick disconnect though you start to see why it shouldn’t be used to install every compressed air driven device there is.   You can see in the pictures below that a 1/4″ quick disconnect that goes to a 3/8″ NPT adapter has a .192″ opening at the small end.  A 3/8″ Schedule 40 iron pipe will actually carry a .493″ inner diameter.   If you were to use this quick disconnect on something like a 2″ Heavy Duty Line Vac, you will starve it for air due to the limited ability of the small diameter to carry enough air volume. This, in turn, will limit the performance of the Line Vac.  This is because the through hole on the quick disconnect cannot pass enough air to feed through to the Line Vac.

Inner Diameter of 1/4" quick disconnect.
Inner Diameter of 1/4″ quick disconnect.

On the 1/4″ quick disconnect to a 3/8″ NPT this may not be as large as a problem as the next picture.  Below you can see a 1/2″ quick disconnect that is going up to a 3/4″ NPT.  a 3/4″NPT Schedule 40 iron pipe is actually a .824″ inner diameter.  The quick disconnect at most has a .401″ inner diameter.

IMG_4614
1/2″ quick disconnects

 

Inner diameter of 1/2" quick disconnect.
Inner diameter of 1/2″ quick disconnect.

Even though you are providing the correct thread size for your connection (a 3/8 MNPT and a 3/4 FNPT respectively in our example) the quick disconnect’s small inside diameter could be too much of a restriction for the volume demanded by an end use product. Due to this restriction point you will see pressure drops in your system when using a device with a properly sized inlet for its demand of compressed air being fed with an improperly sized quick disconnect.  This is one of the main reasons one of our first questions in troubleshooting an EXAIR products performance with a customer is whether or not they are using quick disconnects.

If you would like to learn more about how to properly plumb your EXAIR Intelligent Compressed Air Product, feel free to contact us, or take a look around our Knowledge Base.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

 

 

3 Common Mistakes in Your Compressed Air System

Every day I speak with engineers who are having trouble using compressed air products. A common problem they have is not providing an adequate air supply to their unit. I go through a basic troubleshooting technique to ensure that their pressure and flow rate is adequate. I ask them to install tee on the inlet to the compressed air product in order to install a pressure gauge right at the inlet to the pipe. This allows us to know exactly what pressure we are supplying to the product. Customers are always surprised how the gauge on the compressor or the regulator may read 120 PSIG, but the gage on the inlet to the compressed air product is significantly less.

Last year, my colleague, Russell Bowman, made an excellent video showing how the inlet pressure at the knife will have a significant impact on the performance of the Super Air Knife.  In the video, he changes the length and ID of the compressed air supply to illustrate the difference a proper supply line will have on the performance of a compressed air products.

Not providing adequate air supply is commonly caused by these three mistakes, when plumbing compressed air systems.

1. Incorrectly Sized Piping – This can be the single biggest problem. A lack of planning before installing a compressed air product. Not all compressed air systems are created equal. Though a 1/4″ shop air hose may work for a number our products, some of our products require a larger air line because they require more volume of air to be effective. We often speak with customers an illustrate this problem by stating small air lines are like trying to feed a fire hose with a garden hose – there simply is not enough volume to create the pressure necessary to reach the fire, or solve the application in our scenarios. We publish the flow rates for all of our products and make inlet pipe size recommendation in the installation and maintenance guide furnish with the products so you may avoid this common problem. We also have air data tables in our Knowledge Base or  you may consult an application engineer who will be happy to make the proper recommendation.

2. Quick Disconnects – These handy connectors are great when operating a brad nailer, or a small blow gun, but the small through diameter can severely limit the flow rate into a long air knife, large diameter air operated conveyor, or big vortex tubes.  Due to this fact it is strongly advised to use threaded fittings or over-sized quick disconnects.

3. Adding extra hose or pipe – Extra hose is never a bad thing, right? No, an extra 30 feet of air hose can significantly drop the pressure of a compressed air system. 20 feet of ½ Pipe can flow 70 CFM with a 5 PSI pressure drop.  50 feet of ½” pipe will only flow 42 SCFM with the same 5 PSIG pressure drop. Keep your hose or pipe lengths to a minimum to improve the volume of air you can deliver to a compressed air product.

Dave Woerner
Application Engineer
DaveWoerner@EXAIR.com
@EXAIR_DW

Video Blog: Chip Trapper Filter Bag Installation/Replacement

I’ve taken a few phone calls from EXAIR customers using the Chip Trapper for the first time, needing clarification about the filter bag installation.  The video below shows how simple and quick it is to install and uninstall for replacement. Replacement filter bags are available in 1, 5, 25, 50, 100 and 200 micron filtration.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE