Pressure drop comes in different forms, and it causes inefficiencies within your pneumatic system. EXAIR writes statements in the installation manuals to help find the correct pipe sizes to supply the different products. (Reference Super Air Knife Installation Manual above). But there are other areas that can affect the performance. These can be fittings, tubing, valves, and accessories. In this blog, I will cover some pitfalls that can minimize the potential of your EXAIR products.
Pressure drop by definition is a difference or loss in pressure. A properly sized Filter Separator will typically have a pressure drop of 5 PSID (0.3 bar) at the rated conditions. So, if you start with 100 PSIG (6.9 bar), the air pressure after the filter separator will be 95 PSIG (6.6 bar). But what happens when a filter separator is undersized or too small? The pressure drop will be much higher. So, if the pressure drop is 30 PSID (2 bar), then the downstream air pressure will only be 70 PSIG (4.8 bar). At that pressure, you may not be able to get the performance that is required to do the job.
The first thing in determining these potential issues is what I like to call forensics. If you can install a pressure gage at the inlet of any EXAIR product, then you can deduce if a potential problem is within your setup. For example, if the Pressure Regulator is at 100 PSIG (6.9 bar), and the pressure gauge at the inlet is reading only 60 PSIG (4.1 bar), then there is a pressure drop of 40 PSID (2.8 bar) between these two points. You can look in this area for the problem or problems. If the gauge on the Pressure Regulator goes down as well when you are operating, then the problem area is upstream of the Pressure Regulator. This can be from the pipe size or the air compressor.
The most common issues are fittings and tubing. With fittings, small openings may not allow enough air to pass through. Above is a photo of some typical fittings. You notice that the right side of the chart has large enough openings to decrease pressure drop. In some instances, quick connect fittings are commonly used to easily connect or disconnect pneumatic devices; but if you use too small or too many of these fittings, they can cause a large pressure drop.
The other problem is with the inner diameter of tubing, hoses, or pipes that are not properly sized. Russ Bowman, a colleague, created a video showing the issues with improperly sized plumbing. It is a very interesting video that shows the effect on a Super Air Knife.
If you want to get the most from your EXAIR products, you will need to reduce the amount of pressure drop in your system. Pressure drop is wasted energy and can affect your pneumatic system. You can follow my recommendations above. Or if you would like to discuss your setup with an Application Engineer, we will be happy to assist.
John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb