Compressed air piping systems are designed to provide safe, clean, and quality air from the compressor to the end use equipment for various applications. They are a crucial piece of equipment used to deliver a reliable source of compressed air throughout your plant. Air piping comes in a range of various materials and this article will discuss the different types of technologies to connect. For example, Galvanised and black steel are two materials that will require to be either threaded or welded when installing. On the contrary, stainless steel, copper, aluminium and plastic materials will be connected utilising crimping, brazing / soldering or fittings. Connection types or technologies will be the way we have chosen to group air piping systems in this article.

AIR PIPE SYSTEM - THREADED OR WELDED

AIR PIPING CONNECTION TECHNOLOGY

Threading or welding is one process used to connect an air piping system. Both these technologies require the air piping material to have a thicker wall to facilitate threading or welding. Threaded pipe requires sufficient wall thickness as material must be removed to allow room for the threads to be cut into it. In the case of welding connections to the pipe, this also requires sufficient material to avoid blow through.  In addition, welding and threading are long processes that increase labour costs, especially when it requires skilled workers. Threaded pipe is also harder to source than standard piping.

PIPING MATERIAL (GALVANISED & BLACK STEEL)

Two materials that can only be threaded or welded when installing your air piping system are galvanised and black steel pipes. Steel is a material that has been used for decades, which has the benefit of being readily available. Unlike galvanised pipe, black pipe is uncoated and is significantly more susceptible to corrosion. The coating inside the galvanised pipe may be prone to pieces of coating flaking off and building up. Both these materials are relatively heavy and due to increased wall thickness, the material is now heavier, requiring a labour intensive set up. Heavy materials also present safety hazards, especially when working at heights, so safety measures must be implemented. This also means modifying and maintaining these systems built from steel pipe will be more challenging than other materials. Leaks and blockages typically create a pressure drop meaning you will have to continually raise the pressure of your system to compensate for the loss. Despite being moderately priced, both these materials will require a lengthy installation due to the weight and technologies needed to connect them, increasing costs.

AIR PIPE SYSTEM - FITTINGS

AIR PIPING CONNECTION TECHNOLOGY

The remaining technologies, including crimping, brazing / soldering, and screw fittings, offer a more efficient and effective alternative to installing your air piping system. These methods of connection will allow for a thinner wall in the pipe, resulting in a lighter material with lower installation costs associated. Screw fittings provide a convenient way to add piping which can limit the number of breaks or cuts required. However, it must be ensured to seal fittings correctly and in a safe manner. 

PIPING MATERIAL (STAINLESS STEEL, COPPER, ALUMINIUM & PLASTIC)

Stainless steel, copper, aluminium, and plastic are all lightweight materials that are easier to install due to the connection technologies they require. Using lighter materials will allow for an easier installation process, as safety is the most critical element of any job. These materials are corrosion-resistant, especially stainless steel, commonly used in corrosive environments such as chemical or marine. The protective oxide layer used with stainless steel means it is suitable for industries such as food and beverage production. Stainless steel and copper can be crimped using special crimping tools with compression fittings, which adds strong and reliable joints. Having strong joints is essential to any efficient air piping system as this will minimise leaks over an extended period. Copper is a reliable material that can also be soldered; however, it comes with its disadvantages, one being the cost of copper itself. The price of copper has increased 21.65% since the beginning of 2021, meaning it is the most expensive material available, this often results in consumers seeking cheaper alternatives. 

On the other side of the spectrum, materials such as plastic and aluminium use fittings to connect. Both materials are lightweight and easy to attach or modify, which means labour savings can be achieved while remaining safe. Plastic piping may be cheap, corrosion-resistant and reliable, but this will depend on the type of plastic you use. Plastic materials such as Acrylonitrile butadiene styrene (ABS), Polyethylene (PE) and High-density polyethylene (HDPE) are suitable choices for compressed air as they do not degrade over time. PVC is not recommended as it cannot withstand the pressure necessary for a compressed air system and becomes brittle with time. ABS, PE and HDPE fittings are designed to be used in air piping systems which makes them more reliable as they can withstand the pressure. The main difference between these materials and PVC is that many compressors will require a lubricating oil that can aspirate out into the air stream, this oil is corrosive to PVC. High-density polyethylene (HDPE) has stronger intermolecular forces and tensile strength than other polyethene forms, making it a more durable material that can withstand higher temperatures. 

It is essential to know which oils your plastic air piping system can withstand when changing your compressor type. The reason for this is because each type of plastic will have an oil that it is recommended to be used with.

Another thing to consider is installation costs, the costs associated with installing plastic may outweigh the costs of installing aluminium. Plastic will require a saddle every 300mm for further support to prevent it sagging down otherwise water will sit and gather. Aluminium only requires a saddle every 3 metres due to being a rigid and strong material it will not sag over time. Despite plastic being a cheaper material, it takes longer to install which increases your labour costs. Aluminium is a reliable choice for air piping systems and is one of the easiest to install as no threading or soldering is required. The lightweight gland fitting is quick, easy to use and allows for quick alterations when expanding systems. In addition, aluminium materials will not degrade like PVC and are leak-free, providing a reliable air piping system over time.   

The piping material and connection technologies used will play an important role in influencing your air piping system's installation process, cost, and reliability. Overall, the technology any given connection type uses plays a significant role in determining the benefits you will attain from your air piping system.

Ensure you always choose the correct air piping which is specifically designed for air piping and look at the long-term net costs of your system. Safety should always be your biggest driver in the choice of the new piping system.

For more information or if you need help installing your piping system, contact one of CAPS Australia’s experts on 1800 802 697 or send us an email at info@caps.com.au. CAPS 42 years of expertise in compressed air all around Australia guarantees a quality solution suited specifically for your business, which will perform for years to come.