Ketchup flows better with compressed air.

When I’m not writing and adding content to my websites and blogs, I’m wandering the web looking for neat stuff. For this blog, I try to make “stuff” related to compressed air the focus.

I found the following about how compressed air was used to make ketchup flow effortlessly in a commercial. Yup, this is neat.

“Ever removed the cap from a new bottle of ketchup and attempted to pour the thick tomato sauce contained inside onto an appropriate subject — scrambled eggs, Mom’s mac ‘n’ cheese, Aunt Helen’s Baked Alaska — and nothing came out until you whacked the bottle several times on the bottom or stuck a chopstick down its throat?”

Here’s more on this Ketchup story, including a video.

Watch out for sideloading, it will destroy your air actuators.

Sideloading of an air cylinder rod will increase wear on the rod bearings (the place where the rod comes out of the air cylinder), the piston seals, and ultimately, if it’s severe  enough, on the wall of the air cylinder. Here’s information on sideloading.

The resulting wear causes  a loss of air pressure through worn seals and a loss of force in the actuator. In really bad cases the air cylinder ord will freeze as the piston jams up against the barrel as it extends or retracts.

Consider using an oversized rod when you buy an air cylinder. The oversize rod will have an larger than normal (for that barrel diameter) rod bearing, and this will help reduce sideloading.

Another option is a stop tube. With this you get a longer than needed air cylinder, and at the rod end inside the barrel a stop tube is inserted which prevents the piston from moving all the way to the end of the air cylinder. This keeps a greater distance between the load and the piston, allowing greater resistance to the sideload force.

The most effective remedy for sideload is to remove it! Use flexible tooling connections, and a floating rear clevis on the cylinder mount to allow the cylinder to move from side to side as sideload occurs. This will extend the usable life of your air cylinder.

‘T’ Shirt Cannon…. wooohooooo!

If you’ve ever been to a pro sports game, you will have seen, I’m sure, the promoters shooting T-shirts into the stands from a cannon.

The site I’m about to send you to shows you how to build one of these T-shirt cannons.

However, the design shows how to make one using PVC pipe, and that I’m not recommending. Plastic pipe is not recommended for compressed air use as when it shatters, pieces of plastic shrapnel fly everywhere, including into anyone nearby. Don’t use plastic pipe.

Still, neat work on their behalf. Here’s the T-shirt cannon. I hope you’ve got your “pop-up” blocker working.

When to use what type of compressed air filter?

There are general purpose air filters, coalescent air filters and activated charcoal air filters. When do you use which type? This contribution by Norgren, with my thanks.

Three main types of filters exist: the general purpose filter for water and particles, the coalescing oil removal filter for oil aerosols, and the activated carbon filter for the removal of oil vapors.

Use general purpose filters for main headers, branch lines, tools, cylinders, valves and valve circuits, air agitators, packaging machines, etc.

Use oil removal filters when sub-micron cleanliness or oil-free air is required, such as for the supply to fluidic devices, painting or coating processes, instrumentation, air gauging equipment, air bearings, and medical applications or areas where typical synthetic compressor oils may damage commonly used Buna rubber such as non-lubricated power circuits.

Finally, use activated carbon filters for systems where the oil vapors in the air are not acceptable, such as instrumentation, medical, or packaging systems where the compressed air may come into contact with the product, such as pharmaceuticals.

Compressed air and pool filters; a dangerous combination

While not strictly to do with compressed air, this article caught my attention, and I thought I’d bring it to you for your information.

It seems that pool filters, during operation, can accumulate air at the top of the filter under the lid, and that air, being compressible, can actually do so, and begin to exert force on the filter lid.

A filter lid that has, for example, has 90 square inches of internal surface area, can, when exerted on by compressed air at 2o PSI, undergo 1800 lbs. of lifting force on the pool filter lid, and that force is continuous as the filter is running, trying to force the pool filter lid up.

Should that lid not be attached securely, or, over time, the attaching mechanism become worn, the lid can break free at tremendous speed, causing injury or death.

As a compressed air user you know how powerful an energy force compressed air can be. It’s too bad that compressed air force can be lurking in an unobtrusive location, and it too can be a danger. This website provides more information. It’s worthwhile reading if you have a pool filter.

Are compressed air fittings supposed to corrode?

I just took apart some older fittings. I was unhappy to find that though they still looked shiny on the outside, and on the quick connect side,  on the thread side, the inner passage was badly rusted.  The connects were labeled AMFLO C21.  I took apart several more and they were  also rusted.

Is this just a problem with this brand or is it common?

Do I have to take apart fittings one a year or so to check them?

Or should use I only Brass?

How long should a fitting last?

Or is this due to the fact that I had brass connected to non-brass?

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The vast majority of compressed air fittings are made of brass, stainless steel, nickel plating and composite plastic.

Rarely is an air fitting made of plated steel, as the end result will be just what you’ve described, erosion of the plate and corrosion of the underlying metal.

I’m not going to comment on the product you refer to, as I’ve never used it.

What I can tell you is that you MUST buy brass or nickel plated brass fittings for use in compressed air systems. If the fitting is a composite, the body being made of high impact plastic with metal components, those metal components must be brass or nickel plated brass.

I’m not sure why the major air fitting manufacturers all seem to plate the brass portions of their fittings with nickel. Is it appearance, improved flow characteristics…, there is a reason, as they wouldn’t add the cost of nickel plating to the cost of manufacturing the fitting if it weren’t deemed necessary.

In any case, whether the brass is nickel plated or not, these fittings won’t rust, even if the plating gets abraded on the inside by air, water and particulates passing through them at cyclonic speed.

That you have a rust problem in your fittings tells me that you’ve somehow acquired a plated steel fitting, and as far as I’m concerned, that’s a no-no.

It’s my suggestion that you visit an industrial compressed air equipment shop and buy your couplers, connectors and fittings from them, making it clear that you want only industrial stainless steel, or nickel plated brass fittings. That will solve your corrosion problem.

And no, if you use the correct fittings, you won’t have to take your air circuit apart and examine the fittings every year or so. In a typical, non-dynamic compressed air installation, the fittings should last for decades.

How To Master Airbrush Painting Techniques

I know many of the people that read this blog are into air brush painting.

JoAnn Bortles has been drawing and painting for 42 years and is an award winning air brush artist as well as the proprietor of Crazy Horse Painting, a well respected motorcycle custom painting shop in North Carolina.

As well as a master airbrush painter, Ms Bortles is an established authority and author.   Her new Book “How to Master Airbrush Techniques” is now available at any bookstore or you can get a personally signed if ordered from her website (www.crazyhorsepainting.com).

Unlike Ms Bortles’ other books, this book focuses completely on airbrush techniques.  From learning what airbrush, paints, and equipment to buy, learning how to use and handle your airbrush, this book is a from A to Z guide on how to airbrush. The book offers  simple techniques that will get you great results fast. From the person who has never picked up an airbrush to the airbrusher that wants to freshen up their technique and learn a few tricks, this book will be the best tool in your studio. This book also has the most extensive troubleshooting quide that has ever been published.

If acquiring this book interests you, contact Ms Bortles directly, or check your on-line or bricks & mortar book store.

Crazy Horse Painting
joann@crazyhorsepainting.com
Phone: (704) 843-3780
Mailing Address:
PO Box 623
Waxhaw, NC 28173

A Mexican visitor in China asks about solenoid valves.

Hi. I’m in China. As it is hard to explain to my workers some things I need, I decided to do some simple tasks by myself.

I’ve found so interesting this pneumatics field that I didn’t enter before. I’m Mexican. Buying pneumatics stuff  in Mexico is so expensive. Here, just 1 or 2 cents of USD for any piece you want, so the possibilities are infinite…but, for that price, I won’t get enough support, so I look for assistance from you.

My questions are these….

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Bill answers…

Hello Francisco. Very nice to hear from Mexico via China!

I’ve taken your questions and listed them below, and answered each as best I can.

#1) What is the small bolt located at the bottom of the solenoid valves? This bolt may be pressed down and turned about 90 degrees.

Answer: Without seeing a photo it’s hard to be sure, but I suspect what you are referring to is a manual over-ride. This allows the valve to be shifted manually to direct the compressed air to a different valve port.

The use of a valve manual over-ride is also a  way to diagnose a fault in air circuit. If an air cylinder isn’t responding as it should, once you’ve made sure it’s safe to do so and the compressed air supply is on, you can manually actuate the valve with the over-ride.  If the cylinder works while you are manually operating the valve, that would suggest that the fault in the compressed air circuit is in the valve, not the cylinder.

#2)  What is the difference of a valve with a single or double solenoid? I mean the difference in functions.

Answer: Most single solenoid valves shift when the solenoid is energized. In the absence of an electrical signal to the solenoid, an spring inside the valve returns the spool or poppet to the de-energized location. That’s a single solenoid, spring return compressed air valve.

If you have a double solenoid on a valve, then the circuit designer decided that he didn’t want that valve to shift back automatically when the solenoid was de-energized. Adding the second solenoid instead of an internal spring return would accomplish this. Sometimes 3-position valves have two internal springs and two solenoids, providing a different function. You need to know if your air valves are 2 or 3 position to understand what that double solenoid valve is supposed to do in the circuit.

#3) I’ve seen some applications that have a small tank (something like an accumulator). What is that for?

Answer: Again, very difficult to be sure without seeing it, but I suspect that it’s a pneumatic timing device that will allow an air signal to decay slowly in an air control circuit, thereby allowing something else in the circuit to occur before the valve shifts back. Back when PLC’s were very expensive, people used to build air circuits that ran with air signals only, no electricity. Nowadays, and particularly in China, small, capable PLC’s are low cost, and it’s almost always better to use a PLC and solenoid valves for circuits now that to try to build an air logic circuit. Air logic still has it’s place (particularly in flammable locations) but solenoids are the way to go for most air circuits these days.

#4) There are some devices that feed (step by step) a coil of material into a press. In my factory we punch brass (to make key blanks) and we are considering to purchase one of these air feeders but would like to know how it works. Do you know them? Can you help me to understand?

Answer: There are a number of pneumatic companies that make pneumatic press feed circuits. Yes, I do know how they work. In terms of their function, it’s a system whereby an air circuit alternately clamps, strokes, unclamps and returns,  to regularly feed a fixed length of product into a press.

I’m afraid if you’re looking for installation assistance, you’ll have to either get a local vendor to help, research press feed circuits from some of the pneumatic manufacturers around the world, or pay me to come to China to help! I was there a few years back, and wouldn’t mind visiting again.

Cheers,

Bill

In response to the compressor popping breakers…

When I try to use my compressor, it will run for about two seconds the trip the electrical breaker that it is plugged into. I have tried four different circuits with the same results. What can I do to remedy this problem?

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That you have tried four different electrical supply circuits with the same results clearly indicates a problem with your compressor and not the supply circuit.

The breaker trips because the compressor circuit is drawing more amperage than the circuit can provide, and that’s caused by a fault of some sort in the compressor itself.

I think we can assume that there’s not a short in the power supply to the compressor (power cord) as if there were, the breaker would pop instantly.

The compressor turns on when you plug it in because the pressure in the tank is below the pressure switch cut-in pressure setting.

Since the compressor pressure switch reacts to system pressure, in your case it’s already switched and “calling” for power to flow to the electric motor when you plug the compressor in, since you indicate that the compressor starts and runs for two seconds before popping the breaker.

Now, does the motor actually start, or does it just try to start? I ask this because if your unloader valve hasn’t  “dumped” the air over the piston when the compressor last stopped, that trapped air might overload the motor to the point that the breaker pops.

It seems to me that your pressure switch is OK, since if there were a short in it, the breaker would pop immediately you plugged in the power cord, not wait 2 seconds.

That your compressor starts and runs for two seconds suggests that your motor capacitor is OK, else the motor wouldn’t start at all.

I think you’ve got a motor problem.

Though it could be the motor itself that’s failing, drawing too much power as it tries to start and overcome whatever is ailing it, it could also be that there’s a mechanical issue with the compressor power train, and that mechanical issue is overloading the motor shaft, creating additional load on the motor and starting circuit, and forcing the motor to draw too much amperage which pops the breaker.

So, if the compressor unloaded the last time it ran (it goes psssshhhttt for a second or so to let the air out over the piston when it stops), and if the motor actually starts and runs for 2 seconds, and assuming this is a new condition and the compressor ran with these electrical supplies before (the motor amperage normally doesn’t exceed the circuit) then your problem is likely from the motor to the actual compressor pump, somewhere in there.

How long will it take your compressor to fill your air tank?

Another reader has written in to my ASK page with a question about how long it will take to fill a compressor’s air tank.

I did some research, and came up with an answer here. As I say on the page, I’m not an engineer, and though I’ve researched the subject carefully, if you want an absolutely got-to-be-certain formula, hire an engineer. This one’s a good guideline.