Okay, I will admit, the title may be a tad bit leading. The fact is, it can be done. I speak to customers almost daily who are struggling with the noise levels produced from open pipe blowoffs. With Noise Induced Hearing Loss (NIHL) a significant problem among manufacturing workers, reducing the noise form compressed air can be a simple solution and contribute toward reducing overall noise exposure levels. Many of these calls and emails revolve around reducing these exact noise levels, sometimes the open pipes have existing threads on them to install the solution immediately.
To reduce these noise levels, we need to simply reduce the amount of energy that is being expelled through the pipe. How do we do this you might ask? The use of an air nozzle will reduce the energy being dispersed from an open pipe. This will result in lower air consumption as well as lower sound levels while actually increasing velocity as the pipe will maintain higher operating pressures. Be cautious about the air nozzle you choose, however, they are not all created equal. EXAIR’s engineered air nozzles are among the quietest and most efficient air nozzles available.
What size pipes can we fit nozzles to? That’s a great question. We have nozzles that range from a 4mm straight thread all the way up to 1-1/4″ NPT thread. This also includes nearly any size in between especially the standard compressed air piping sizes. For instance, a 1/4″ Sched. 40 pipe that has 1/4″ MNPT threads on it can easily produce over a 100 dBA noise level from 3 feet away. This can easily be reduced to below 80 dBA from 3′ away by utilizing one of our model 1100 Super Air Nozzles. All it takes is a deep well socket and ratchet with some thread sealant.
This doesn’t just lower the sound level though, it reduces the amount of compressed air expelled through that open pipe by creating a restriction on the exit point. This permits the compressed air to reach a higher line pressure causing a higher exit velocity and due to the engineering within the nozzle, this will also eliminate dangerous dead-end pressure and complies with OSHA standard 29 CFR 1910.242(b).
All in all, a 30-second install can make an operator’s work station considerably quieter and potentially remove the need for hearing protection. If you would like to discuss how to lower noise levels in your facility, contact us.
I recently received an inquiry from a customer to test their current air guns through our Efficiency Lab service. According to the operators, the handheld blow gun they were purchasing from a commercial retailer was too loud and complaints were rolling in. They were also hoping to save some compressed air in the process as they were performing an energy audit at the same time.
The gun they sent in looked fairly similar to our Precision Safety Air Gun but it did not have an engineered nozzle on the tip of it. Instead, it was simply a cross cut hole in a piece of material. The air inlet to the gun was a 1/4″ NPT just like our Precision Safety Air Gun, the extension on the gun was slightly longer, the only significant variance I saw was the tip.
To try and get as much information as possible I measured the O.D. and I.D. of the extension, the hole size was approximately .140″. I measured the extension on our Precision Safety Air Gun just to see what is different, it came in at the same size. So, I flow tested the competitive blow gun with their tip on it and came up with air consumption of 12.69 SCFM, noise level of 92 dBA at 3′ away, and a blowing force of 11.5 oz at 80 psig. I then measured the same attributes of EXAIR’s model 1410SS-CS Precision Safety Air Gun at 80 psig inlet pressure. The model 1410SS-CS measured 8.3 SCFM, gave 8.1 ozs of working force, and only produced a 75 dBA sound level from 3′ away.
The sound level reduction was a total of 17 dBA which is below the OSHA standard for allowable noise level exposure, as well as reduced their air consumption by 4.39 SCFM. That is almost a 35% reduction in their compressed air usage per gun replaced. After seeing these levels of reduction the customer had more than enough information to provide management with in order to replace the blow guns not just for noise level reduction but also because it will reduce air use and save money. A clear supportive role in their energy audit.
When the operating air pressure within a manufacturing facility drops it is easily noticed. This is because the equipment that is depending on that air pressure to stay above a set point will generally stop working and halt in an alarm state safely. (This is not always the case and in fact I have personally seen machines crash due to low compressed air pressure.) This creates down time, safety hazards, equipment hazards and is all around not good for production. This is why low pressure alarms are taken very seriously in most facilities.(See the video below.)
Sometimes the reason behind low air pressure in areas is easy to find. If the alarm happens every time a machine reaches a point in the production cycle where air is used to blow parts off then the point of use blow off can be looked at to see how its efficiency can be maximized. Other times it is not so simple. There may not be a pattern to when the low pressure alarm goes off and therefore cannot be easily traced. This is where the 6 Steps To Compressed Air Optimization comes in to play. The best way to narrow down what area the fault is generating in is to get some base line measurements on the total air usage for the system by using a product like the Digital Flowmeter with USB Data logger.
Once the baseline is known for the complete system, measuring the main branch lines for the systems will then need to be performed. This could be on the main header where it branches off to individual areas of the plant, or if it is a small shop any line that is off the main header. By recording the usage over a period of time it will highlight use trends including low use/high use times and random spikes in demand you may not be aware of. The next step would be to then look further into the high use and random spikes. If a flow meter is placed on individual legs of the air system, it will be easier to determine what area of the plant is causing high use, or knowing what processes occur during the time period shown in the data.
By having flow meters on individual branches the cause of the high demand on the compressed air system will become very clearer, whether it be an open pipe blow off, stuck valve on a drain, or just an operator not paying attention, the cause will be able to be determined and eliminated.
EXAIR offers a full range of Digital Flowmeters with USB data loggers and we offer custom calibrations as well as sizes to fit virtually any compressed air piping you may have within your facility. Feel free to contact an Application Engineer to discuss the possibilities.
Life is full of change. It might sound trite, but truer words were never spoken. I used to get up around 6:30 on work days. Now, thanks to my son’s middle school schedule, I’m usually seeing him out the door at that time. Getting up earlier was certainly a difficult change at first, but it’s had its benefits. Not the least of which is spending a little extra time with the boy in the morning.
One of our favorite things to do while eating breakfast is to watch the ‘How things are made’ types of shows. Of course, watching these types of shows with an engineer has its downside. While we can usually explain exactly what’s happening in the process of whatever is being made, the problem is that we often do. Meaning we wind up talking over the program, which, ironically, is one of my greatest pet peeves. Speaking of change, guess that’s something I need to work on…
At any rate, this morning we saw a show on making saltines. At the sight of the copper pipe positioned near where the cracker dough comes off the die-cut wheel, I knew exactly what was up. ‘They’re using drilled pipe! That’s not safe and a HUGE waste of compressed air! That’s the perfect application for a Super Air Knife!” Guess watching these programs with an EXAIR engineer has an additional risk: We can get a little over-excited when we see OSHA violations and wastes of compressed air! I think I about made my son jump out of his gym shorts, but he’s watched these sorts of shows with me before. He knew the risks…
Life is full of change, and while perhaps I can get better at not talking while the TV show is on, I doubt I’ll ever stop cringing at safety violations and wasting compressed air. Do you have drilled pipe in your plant? If so, you could be in violation of multiple safety standards and are definitely wasting money on compressed air. EXAIR can help you minimize harmful noise levels and keep you in compliance with OSHA’s dead-end pressure standard. Please give EXAIR a call to begin saving air and increasing safety!