Owners of compressed air piping systems tend to focus on the compressors and think of the piping as less of a concern. However, just as hearts can fail due to clogged arteries, compressors can fail due to poor piping. And even if it doesn’t fail outright, power lost to faulty or inefficient pipes can cut into your profits. To manage your costs, you must pay attention to various aspects of your piping system, including the layout, installation and maintenance.
How Do Air Compressor Piping Systems Work?
The purpose of compressed air piping systems is simple: to deliver compressed air to where it is needed. However, designing a compressed air system is more difficult than you might imagine — the compressed air has to be delivered with sufficient volume, good enough quality and enough pressure to power the components that require compressed air. If your compressed air piping design is not well done, your energy costs will go up, your equipment may fail, production efficiencies may be reduced and more maintenance may be required.
What Types of Pipes Can You Use with an Air Compressor System?
An essential first question when planning a new compressed air system is, “What type of pipe should I use for my air compressor?” You have two primary options: plastic and metal. Below, we will discuss the advantages and disadvantages of each in detail and address some of the myths that surround each one.
Plastic Pipes
- Resistance to corrosion: This means you don’t have to worry about rust falling off your pipes and dropping into your airflow. This, in turn, reduces the risk of obstructions.
- Smooth, interior surface: The interior of a plastic pipe never deteriorates, which encourages laminar flow.
- Lightweight: Plastic piping is lightweight, making it simple to transport and fit.
- Easy to cut: Cutting plastic pipes is easy and only requires basic tools.
- Easy to connect: Plastic pipes can be glued together, which is less costly and quicker than connecting metal pipes, which must be welded together.
There are several types of plastic pipes as follows:
- Acrylonitrile Butadiene Styrene (ABS): You can find ABS in a variety of products, from car fenders to LEGO -brand toy bricks.
- Polyethylene (PE): This kind of piping is produced specifically for compressed air systems.
- High-density polyethylene (HDPE): This is yet another suitable plastic for compressed air pipes.
- More well-known: Metal is more traditional, which means more technicians know how to install the pipes.
Metal Pipes
- Longer safety track record: Having been in service longer, metal piping has proven its strength against fracture, splits and blowouts.
- They’re guaranteed not to change shape: While certain plastic materials offer great strength, metal’s inherent rigidity guarantees it won’t warp.
- Impervious to degradation: Compressor lubricants will not degrade metal pipes.
Piping Layout Considerations that Increase Pressure Efficiency
When designing a compressed air piping system, you might think you should focus on the connectors. After all, this is where leaks are most likely to occur, and most people assume leaks to be the greatest threat to their system’s efficiency. However, that is not necessarily the case.
Sharp Angles
A sharp angle in your piping system will slow down the airflow, reducing pressure. Think of compressed airflow like the flow of traffic on highways: when turning sharply, you have to slow down. Coming out of a bend requires concentration — you need to correct any overcompensation for the turn and account for any unexpected objects on the new road.
Moisture
Water corrodes certain kinds of pipes, causing rust flakes to break off and travel through the piping ystem. These rust flakes, together with vapour, will make their way into your end-use equipment and may clog up nozzles and contaminate materials that you intend for the compressed air to deliver or apply.
Obstructions
If a piping system experiences corrosion, this is a cause for concern, as the corroded surface can flake off and accumulate into obstructions. The primary points of restriction in the piping system are where the connectors, valves or devices such as sensors or dryers are located. These components may decrease the pipe diameter through which the air can flow, and they also accumulate particles in the air stream. An accumulation of particulates on these devices will lower pressure available downstream —as well as back up the pressure upstream.
Think about the Future
When designing your layout, make sure that you can expand or make another drop easily. This is easy when you’re first installing, but it can be costly and a major pain to go back and modify later unless your piping system is modular. If you think expansion may be likely, you may want to think about oversizing your pipe. It never hurts to have a bigger pipe and, as mentioned before, it’s a huge hassle to go back and modify your installation.
Install Drip Legs
If your system doesn’t have a membrane, refrigerated or desiccant dryer, you’ll have to install drip legs in the pipe. Remember that compressors squeeze large amounts of water out of the air, and a filter can only remove some of it. Without a dryer, more water will condense inside the pipe, and this water only has two places to go: either back into your compressor or into your equipment, and both of these scenarios will likely lead to damage. A drip leg, however, will allow this water to escape from the pipe without doing any damage to your equipment. Just don’t forget to drain it or put an automatic drain on it. A drip leg is very simple to install, and we recommend it even if you already have a dryer, as it will serve as a backup if your dryer fails.
Install Ball Valves and Unions
Sooner or later, something will break and will need to be repaired, and a ball valve allows you to isolate the broken component from the system. For this reason, you should install a ball valve before or after each major component. We also recommend that you install a union before or after all major components as well as between pipes. If something needs to be changed out, a union can save you many hours of work. Putting in unions can also speed up your installation.
Rohan Kuldhar is a Project Sales Engineer at Fusion HVAC Solutions Pvt Ltd. He possesses a BE Mechanical degree.
