Consider these Variables When Choosing Compressed Air Pipe Size

Here on the EXAIR blog we discuss pressure drops, correct plumbing, pipe sizing, and friction losses within your piping system from time to time.   We will generally even give recommendations on what size piping to use.  These are the variables that you will want to consider when selecting a piping size that will suit your need and give the ability to expand if needed.

The variables to know for a new piping run are as follows.

  • Flow Rate (SCFM) of demand side (products needing the supplied compressed air)
  • System Pressure (psig) – Safe operating pressure that will account for pressure drops.
  • Minimum Operating Pressure Allowed (psig) – Lowest pressure permitted by any demand side point of use product.
  • Total Length of Piping System (feet)
  • Piping Cost ($)
  • Installation Cost ($)
  • Operational Hours ( hr.)
  • Electical Costs ($/kwh)
  • Project Life (years) – Is there a planned expansion?

An equation can be used to calculate the diameter of pipe required for a known flow rate and allowable pressure drop.   The equation is shown below.

A = (144 x Q x Pa) / (V x 60 x (Pd + Pa)
A = Cross-Sectional are of the pipe bore. (sq. in.).
Q = Flow rate (cubic ft. / min of free air)
Pa = Prevailing atmospheric absolute pressure (psia)
Pd  = Compressor discharge gauge pressure (psig)
V = Design pipe velocity ( ft/sec)

If all of these variables are not known, there are also reference charts which will eliminate the variables needed to total flow rate required for the system, as well as the total length of the piping. The chart shown below was taken from EXAIR’s Knowledge Base.

Airflow Through 1/4″ Shed. 40 Pipe

Once the piping size is selected to meet the needs of the system the future potential of expansion should be taken into account and anticipated for.   If no expansion is planned, simply take your length of pipe and start looking at your cost per foot and installation costs.    If expansions are planned and known, consider supplying the equipment now and accounting for it if the additional capital expenditure is acceptable at this point.

The benefits to having properly sized compressed air lines for the entire facility and for the long term expansion goals makes life easier.   When production is increased, or when new machinery is added there is not a need to re-engineer the entire system in order to get enough capacity to that last machine.   If the main compressed air system is undersized then optimal performance for the facility will never be achieved.   By not taking the above variables into consideration or just using what is cheapest is simply setting the system up for failure and inefficiencies.   All of these considerations lead to an optimized compressed air system which leads to a sustainable utility.

Brian Farno
Application Engineer Manager

Super Air Wipe and Back Blow Nozzle Increase Production at a Pipe Manufacturer

Last week I took a call from a pipe and tube manufacturer who was looking for a solution for two problem areas within their process of manufacturing 1″ pipe.

First, they were removing moisture from the outside of the pipe after a rinse cycle, to prepare the material for painting. To remove the water, they had an operator with a hand held blow gun and shop rag who blows off the residual fluid, then manually wipes it clean. This process added time to their process, reduced overall production and increased labor.

Since 1″ schedule 40 pipe has a 1.3″ outside diameter, I recommended they use our 2″ Super Air Wipe for this particular part of the process. The Super Air Wipe produces a 360° ring of air to clean, cool or dry the outside surface of a hose, tube, pipe, etc. as it passes through the center of the unit. Installation is simple as the unit features a split design which can easily be clamped around the material, with the need to remove it from the machine.

Super Air Wipe
Super Air Wipes are available from 1/2 up to 11″.

The second issue they were experiencing was as they cut the pipe to length, they are seeing the cutting fluid and scrap chips settle on the inside which again requires the same operator to manually clean this surface as well. I recommended using our Back Blow Air Gun Model # 1204SS-12-CS Soft Grip Safety Air Gun with Model 1004SS Atto Back Blow Nozzle, 12″ aluminum extension and Chip Shield. The Back Blow Nozzle’s airflow is directed away from the nozzle and provides a 360° ring of air, making it the ideal choice for blowing out the I.D. of a pipe. With this particular design, you eliminate the risk of blowing the chips and fluid out of the far end or pushing debris farther into the pipe. It also prevents the potential of blowing debris toward other personnel or machinery. The Chip Shield protects the operator from the particulate being removed for the inside area.


Unique Design For Treating Inside Diameter of Pipe

If you have any questions about these products or would like to discuss your particular application, give us a call so we can help.

Justin Nicholl
Application Engineer

Tiny Engineered Nozzle Saves 91 SCFM for Engine Block Blow-Off

Drilled pipe
Air Box with homemade nozzles

Above, you see a photo of what our customer calls an “air box”. It is aptly named as it consists of approximately 65 homemade nozzles, connected to a large plenum, which are able to be aimed in a variety of directions to blow out the numerous holes that are machined into the bottom of an aluminum engine block.

The engine (1024x621)
Engine Block with multiple holes to be blown out

Each of the nozzles above were hand-made for the air box fixture with an internal hole diameter of 1.6 mm. and which produced a force of about 50 grams with 6 BARG inlet pressure. The goal of reviewing the application was to see what if any EXAIR nozzles could replace these custom-made units to produce an air savings and thus cost savings for operating their fixture.

Model 1108SS Super Air Nozzle

After determining that the existing nozzles consumed 4.1 SCFM @ 6 BARG inlet pressure, I was able to make a comparison to the Super Air Nozzles that make up the smaller end of our flow range. In comparing these nozzles, I was able to determine that the Atto Super Air Nozzle, model 1108SS consumes 2.69 SCFM @ 6 BARG and produces 61 grams of force per nozzle.

The calculated air savings between the existing nozzle and the EXAIR Super Air Nozzle was about 34%. That’s a savings of 1.4 SCFM per nozzle. In terms of sheer air volume, that’s not a lot, BUT when you multiply that up over 65 nozzles, total air savings is 91 SCFM. That is close to saving the full output of a 25 HP air compressor!

And so, if you run out the cost to operate a 25 HP air compressor for a year’s worth of production, the savings becomes quite clear that by simply swapping out these homemade nozzles for an engineered solution with EXAIR Super Air Nozzles, the customer can achieve their goal for reduction in air use. Not to mention a significant reduction in the noise level for the application as well as enhanced safety with OSHA compliant nozzles.

Do you have a blowing application that could benefit from the same kind of simple, swapping of nozzles to bring your production costs down? Give us a call and let us know about your application. We would be happy to discuss with you and provide a similar comparison to determine how much air you could save!

Neal Raker, International Sales Manager

So, How Much Does Your Compressed Air Cost you?

Recently, I had a conversation with my German colleague regarding the cost of compressed air. He was scrutinizing what we say when we say that if you don’t know your cost, you can estimate using a value of $ .25 / 1000 Standard Cubic Feet of compressed air. When you crunch the numbers down to this kind of value, it becomes very easy to see what your new compressed air based solution might cost you or perhaps save you in terms of compressed air savings over the present method.  His opinion was that the rate that we use was a very inexpensive one and so he was looking for some verification.

The first thing I did was to go to trusty old Google and look up the average electricity cost for our state (Ohio) over the past year for a typical industrial electric consumer. The rate I found was $ .0687 / kWh. (Kilowatt hour)

If you take a 15 kW air compressor, this is equal to our rating of 20 HP (15,000 / 746 = 20.1 HP). 15 kW * $ .0687/ kWh = $ 1.03/ hour to operate a 15 kW (20 HP) compressor.

A 20 HP compressor of industrial grade will produce 80 SCFM. It takes 12.5 minutes for an 80 SCFM compressor to produce 1000 SCF of air.

12.5 minutes / 60 minutes = .208 hours to produce 1000 standard cubic feet of air.   .208 hours * $ 1.03 / hour = $ .2142 (21.4 cents) to produce 1000 Standard Cubic Feet
of air.

And so, in showing him my math, I was able to convince my friend that using $ .25 / 1000 SCF is actually a liberal figure in our area in some cases a conservative estimate. Of course our energy prices don’t compare to those in Germany / Europe. So, for him to make this kind of example to his customers would be an even more effective discussion for using our air saving Nozzles, Air Knives, Air Amplifiers and also our Optimization products such as the EFC.

Neal Raker,
Application Engineer

Super Ion Air Knife Improve Cycle Rates in an Injection Molding Process

A die manufacturer created a 12” wide by 24” long (30.5cm X 61 cm) tool for an injection molding machine that contained 80 cavities for an automotive supplier. As contracted with their customer, the goal was to have 30 injection per minute to create 2400 parts every minute.  The tool was designed with 2 chambers, each containing 40 cavities to control production rates.  Also as part of the contract, the automotive supplier required a pre-production approval before signing off on the purchase order.  As they attached the tool to the injection molding machine for a trial run, they began to notice that some of the parts were sticking to the cavities.  In the first 30 minutes, they stopped the machine as they only averaged 16 injections per minute with only 50% of the parts falling out of the tool.  They did notice that they could feel the static electricity on their arms when they reached into the tool to remove the parts.  To try and improve the cycle rate, they attempted to mount a 12” (30.5 cm) pipe with drill holes above the tool. Many manufacturers attempt this because it is simple and easy to do; but, this style of blow-off is very inefficient and not very effective.  As they began the next trial, they did see a slight improvement.  It increased the cycle rate to 19 injection per minute and it was removing 75% of the parts.  It still was not good enough for the automotive supplier.

Super Ion Air Knife Kit includes Super Ion Air Knife, Power Supply, filter, regulator and shim set.
Super Ion Air Knife Kit includes Super Ion Air Knife, Power Supply, filter, regulator and shim set.

The die manufacturer was under pressure to find a solution as he did not want to redesign or rebuild the tool. He noticed that EXAIR was a leader in Static Eliminators and Blow-off equipment, so he contacted us.  In our discussion, he explained how he needed to remove the static and remove the parts quickly out of the tool.  I suggested our model 111212 Super Ion Air Knife Kit.  It is 12” (30.5 cm) long, and it can be mounted easily across the width of the tool.  With a 40:1 amplification ratio and both positive and negative ion streams, it can remove the static and push the parts very effectively.  Once they installed the Super Ion Air Knife, they began the operation once again.  They initially noticed that all the parts were being ejected from the tool.  When they measured the cycle rate, it was running at 33 injection per minute (exceeding the requirement).  The tool was approved and the die manufacture was very pleased.

When it comes to removing static and blowing parts, EXAIR has a great range of products. We can do it very efficiently, quietly, and effectively.  If you have any issues with injection molding, EXAIR may have the product to help you.  You can discuss your applications further by contacting one of our Application Engineers.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Super Air Knives Are Perfect Solution For Electroplating Application

The products on this rack need to be blown off before heat treating

One of our blog readers was searching through our posts, looking for a suitable solution for a problem in their application.  The application needed a system for blowing water from different components on racks (shown above) used during electroplating.  After blow off, these components go through a heat drying process, and it is critical to have as much of the water removed as possible.

Given the width of the rack and the need for even blow off across the full width, the most suitable solution is a pair of Super Air Knives.  The video above shows the dipping process of the rack and components, and this is where the end user wants to install their blow off.

Our recommendation was to mount one Super Air Knife on either side of the rack, across the width. The airflow aimed downward toward the dip tank at a 45 degree angle was also our recommendation.  This will create a complete blow off for the rack and the parts on it, while redirecting the water back into the tank below.  And, these racks have a right to left measurement of 60″, making our stock length 60″ Super Air Knife an ideal candidate for this application.

The consistency and repeatability of the Super Air  Knife provide a unique solution opportunity for this application.  If you have a similar application or application need, contact an EXAIR Application Engineer, we’ll be happy to help.

Lee Evans
Application Engineer


Line Vacs Save Your Time, Your Backs – and Your Money

A while back, I wrote about how Line Vacs Save Time And Backs. Well, it’s happened again, and this time, it’s saving a customer some money, too.

A major manufacturer of machined products used portable electric vacuums to remove chips and coolant from their machines. These electric vacs continually broke down due to clogging, coolant getting into the electric motors, vacuum hose deterioration, etc…all of which caused down time and lost production. They were failing pretty consistently after about 3 months of use.

Electric Vacuums are prone to clogging, wearing out, and motor failure.
Electric Vacuums are prone to clogging, wearing out, and motor failure.

The tanks needed to be emptied on a regular basis as well, meaning the machine operator had to stop what he was doing (which makes the company money) and spend 10-15 minutes emptying out the tank (which does NOT make the company money,) three times per shift, on average. Additionally, the tanks could weigh up to 100lbs when full, so it was no small chore. Although this company reported no injuries (yet,) a common first line in a LOT of workplace back injury reports start out with: “While attempting to lift a 100 pound _____” You get the idea.

After hearing about the EXAIR Line Vac and calling us to discuss, they decided to try a couple of Model 6064 2″ 303SS Line Vacs. These were mounted near the machine with a short section of suction hose to reach inside, with a discharge hose taking the chips & coolant to the disposal bin. So, with a little help from EXAIR, they’ve saved:

*TIME: Machine operators never have to leave their workstations to lug the heavy tanks across the shop for emptying, meaning no work stoppages.

*BACKS: Because they don’t have to worry about those heavy tanks anymore, they’ve eliminated the risk of lifting-related injuries.

*MONEY: With no moving parts to wear or electric motors to burn out, the Line Vacs will run darn near indefinitely, maintenance free.  For an investment of $3,700.00 (2016 List Price for a Model 6064 2″ SS Line Vac is $370.00 x 10 machines,) they’re saving $5,400.00 annually (the current replacement cost of the electric vacuums is $135.00 per unit x 4 per year x 10 machines) for a first-year savings of $2,700.00.

A Line Vac and two pieces of hose are all you need for a durable, easy to use, no maintenance, reliable vacuum conveyor.
A Line Vac and two pieces of hose are all you need for a durable, easy to use, no maintenance, reliable vacuum conveyor.

The first two Line Vacs worked out so well for them, they were able to justify adding them to the other eight machines in their facility. These are operated intermittently, so there’s not a drastic impact on their compressed air system demand. It’s a win-win-win…win.

If you’d like to find out how EXAIR’s engineered compressed air products can produce “wins” for you, give me a call. We ARE keeping score.

Russ Bowman
Application Engineer
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