The Australian compressed air industry has long been dominated by galvanized steel and plastic pipe products, materials borrowed from related industries such as the construction and plumbing sectors. Engineers and contractors have traditionally specified such systems due to low material cost, familiarity, and above all, habit.
More recently, due to the tightening of workplace health and safety regulations, Australian standards and a change in industry thinking, progress has been encouraged; possibly the most important of which is the development of piping systems designed specifically for the distribution of compressed air.
Introduction of aluminum compressed air pipes.
Aluminum pipes were introduced to the industry in the late 1980s as an alternative to plastic and steel; however, they have remained relatively underused and underappreciated until now. This article explores the various differences between aluminum and plastic pipes, and the clear advantages that can be seen in an all-metal system.
1. Aluminum allows for better flow rates.
By comparing the internal diameter of aluminum with that of a plastic pipe of the same external diameter, you will find a great and obvious advantage. The significantly thinner, yet stiffer wall of aluminum provides a much larger internal diameter, resulting in much higher flow rates and reduced pressure drop compared to plastic of the same size. As such, in many cases it is possible to reduce a pipe size when using aluminum, subsequently saving on material costs, while achieving the same or better flow than plastic.
In addition, the leak-free seal created by many aluminum system fittings, coupled with the smooth inside diameter of the internal surface of the tubing, leaves virtually no ridges to cause turbulence and disrupt laminar flow.
2. Aluminum can withstand extreme conditions
Aluminum pipes have been shown to exhibit far superior weather resistance than plastic. Unaffected by sunlight, aluminum is extremely fire resistant and is capable of maintaining a constant working pressure of 15 bar at temperatures up to 80°C. By comparison, the integrity of plastic pipes can be compromised due to prolonged sun exposure, offering minimal fire resistance and experiencing a significant drop in maximum pressure rating with increasing temperatures.
Properly installed, the non-corrosive nature of aluminum means your compressed air network will run efficiently for much longer than any traditional alternative.
3. Aluminum does not expand or contract
Due to its heat-resistant composition, aluminum exhibits minimal expansion and contraction under extreme temperature changes. Plastic, on the other hand, has been shown to expand up to 50mm per 100m of pipe, resulting in substantial buckling of the entire main ring system.
Additionally, while plastic is prone to warping and warping due to thermal expansion, aluminum holds its shape, meaning fewer clips are needed during installation to preserve the long-term structure of the system.
4. Installation is quick and easy.
The rigid nature of aluminum prevents it from sagging and buckling, which means that even over long lengths, it requires fewer clips (every 2-3m) and can be connected by a single technician. During installation, handling of the pipe is easy; however, once folded, it will hold its shape.
Plastic pipes, on the other hand, require more time and labor to install, resulting in much higher labor costs. Prone to substantial sagging, more clips are required to maintain the structure, and additional fittings are required to bend the pipe and keep it in shape.
The influx of aluminum compressed air systems on the market today underscores it as the way of the future for air distribution. While the initial capital cost may be higher than plastic, the long-term savings in installation, maintenance, and production put aluminum at the forefront of the industry.
