When was the last time that you really thought about your compressed air piping system? Distribution piping is an essential component of any compressed air solution system, so “out of sight, out of mind” is not an acceptable option. Considering some best practices regarding proper pipe sizing, efficient piping layouts and design configurations, forward-looking maintenance needs, and piping materials differences will help prevent long-term issues in your piping system, as well as allow your compressed air system to operate with maximum efficiency.
Importance of Proper Pipe Sizing
Properly sized pipe is a critical piece of any distribution compressed air system. If piping is too small for the demand, you have just derailed the main purpose for your compressed air system in the first place – delivering appropriate air levels to satisfy all system components. This mistake will prove to be both inefficient and costly. Pressure drop will be inevitable, and the compressor may be overworked, causing premature wear and additional maintenance requirements. Losses in pressure from inadequate piping will also result in increased energy costs and will eventually have a negative impact on the basic system production process.
Design and Layout Configurations
Since compressed air is costly to manufacture, a properly designed and functioning system are critical to cost savings. A poorly designed compressed air system can greatly increase energy costs, compromise equipment integrity, reduce production efficiencies, and increase maintenance requirements. Conversely, a properly designed air system stands opposed to each of those negatives, while bringing the strong potential to “pay back” the customer over the life of the system.
Start with a Loop
One of the most efficient compressed air piping system designs is a loop system. In a loop system, the air flows in two directions, thus cutting the demand on the overall pipe length in half. The cooperative nature of the loop system results in reduced pressure drop throughout the system and full air flow delivered to downstream equipment, which helps all system components perform at an optimum level. Branch pipes can then be easily run from the main header loop to the various required points of use.
Piping Design Configurations
Three major issues which must be considered when configuring an efficient piping design are: decreasing turbulence, managing air velocity, and minimizing pressure drop. We have already addressed managing air velocity and minimizing pressure drop with proper pipe sizing and a header loop layout. That said, we will focus a bit here on decreasing turbulence. Minimizing bends and sharp directional changes in the design layout is one of the best ways to help reduce turbulence. At its essence, turbulence is simply interrupted air flow. Turbulence negatively impacts air delivery, resulting in wasted energy and money. Turbulence can occur through direct or indirect interference. An example of direct interference is when the air crosses through a pipe fitting (such as a 90* Elbow), causing a slowdown or a significant change in direction. Indirect interference occurs from weak air velocity, usually due to improper pipe sizing or contamination that has built up within the pipes. Think about turbulence when flying on an airplane. Turbulence carries such a negative connotation, that quite often the language is softened, and the pilot will now say that you will be experiencing a little “rough air” instead of turbulence.
Forward-Looking Maintenance Needs
It is always smart to look forward and keep in mind future maintenance needs when planning your compressed air system. Whenever maintenance needs to be done, a bypass system should be in place to allow for uninterrupted operation while maintenance or repairs are accomplished.
Compressed Air Piping Materials
Compressed air piping systems come in a variety of materials, some of which include aluminum, black iron, copper, and plastic. Some materials are easily corroded, leading to debris and particulates in the air stream. Other materials affect the pressure loss due to friction. Still others offer a better option because they have low friction coefficients.
Aluminum is a very popular choice for piping installations because it is light weight, has excellent structural strength, and is highly resistant to corrosion. Its smooth interior means that line losses are reduced, and reconfiguration of the piping system is extremely simple if your facility moves or expands. Although the upfront cost in materials will be higher than black iron, the savings on the installation labor will make up for the difference in material cost.
With its moderate costs and wide availability, black iron has traditionally been one of the most popular of all piping options. However, black iron is difficult to install and maintain. Over time internal rusting and corrosion of the pipe becomes an issue because corrosion impedes air flow and particulates get in the pipe stream, causing damage to equipment. Fittings and pipe are threaded, so large sections of pipe must be taken apart to address leaks. If any changes are required to the piping layout, new pipes must be cut and threaded.
Copper is an excellent, but somewhat expensive material. It provides a smooth, corrosion-free internal wall for low pressure drop. Installation of copper can be time consuming and may require a licensed installer depending on the regulations of your location. Copper can also be unforgiving and expensive when it comes to reconfiguring and making changes to an existing system.
Lightweight and inexpensive, PVC is also a common piping product. It is very easy to install, and reconfigurations are usually not a major problem. However, it is an occupational health risk potential under pressure and high temperatures. It is completely unsupported by OSHA for any compressed air application. Therefore, it is not a viable piping option.
Some Final Thoughts
Various factors and considerations have been covered here that contribute to the optimal performance of a compressed air piping system. So when you are ready to determine the layout, design, and materials of your piping system, it is always recommended that you reach out to a trusted compressed air expert. They’ll be able to walk you through the necessary details of compressed air piping and help ensure your system will function both efficiently and effectively for years to come.
Visit us at www.atlascopco.com/air-usa for more information!