Hoses and pipes are regularly used in pneumatic systems to distribute compressed air to various components of the system. Understanding your plan and hose and pipe selection criteria will ensure that it meets your program requirements.
Chemical resistance of pipe and hose materials
Compressed air contains by-products such as compressor oil, dust particles and condensate. The environment must also be taken into account. Hose or pipe materials must be resistant to all of these materials and conditions. For hoses and pipes, a slightly different definition is used. When referring to pipes, they are usually monolayer. This means that they are made of one material. This material must be chemically resistant to compressor oils and environmental condensate while being protected from any environmental conditions. When referring to the hose, it can be made of different layers of material. So you can be sure that the inner hose material is resistant to compressor oils and condensate, but you can have a second material as the outer shell to protect it from the environment.
Thermoplastic
Most pneumatic pipes and hoses are made of thermoplastic. As mentioned, they can be single-layer or multi-layer, depending on the application. In the following, we will briefly discuss the most common thermoplastics used for pneumatic tubes. However, please read our hose and pipe materials and see our chemical resistance chart for more information on resistance materials.
- Polyurethane (PUR or PU): Corrosion and abrasion resistant, flexible and strong.
- Polyamide (PA or nylon): Lightweight, sturdy, dimensionally stable, good bending radius, good flexural fatigue resistance and low moisture absorption rate. Polyethylene (PE): Flexible, has good chemical resistance and cost-effective Is.
- Polyvinyl Chloride (PVC): Lightweight, flexible and can be sterilized repeatedly without any side effects.
- Polypropylene (PP): Very light, chemical and heat resistant, and has a good surface hardness.
Main air supply
Piping or hoses are used to distribute compressed air from the compressor to the program.
Workshop plumbing
For large industrial workshops, it is often necessary to have multiple connections throughout the workshop to connect pneumatic tools . In these settings, a rigid piping system is usually used because it protects against accidental impact or puncture. However, installing these piping systems is difficult and costly. Because durability is a key criterion, aluminum, copper, stainless steel, or rigid PVC are often used. They also require multiple connections and fittings, which increases the potential for leakage. Ambient temperature must also be considered because pipes can expand and contract as temperature changes. For example, aluminum expands 0.24 mm per meter of pipe for every 10 degrees of temperature rise. It is therefore important that the piping system be routed with these movements in mind, for example using expansion rings.
Air supply lines
Flexible hoses are used with rigid compressed air pipes or alone in smaller workshops. They are also used to provide temporary air or mobile. Because flexibility, ease of installation, and durability are important in these applications, lightweight HDPE or heavy rubber lines are often used. Flexible hoses make fewer connections possible compared to plumbing, and there is less concern about the effect of temperature because it is not rigid. Air supply to parts of pneumatic components such as valves, cylinders or pressure regulators are usually connected to the main air supply line through flexible pipes or hoses. However, they can be reinforced, like a metal-plastic pipe, because it makes them durable, lightweight and flexible. Flexibility is important because of the vibration or movement of the components, so having a flexible hose is important. They are also at the end of the pneumatic cycle, they can have the smallest diameter required. They are connected to the main air supply line and separate components through connections. To understand how to choose connections, please read our Connections article. Common fittings include barbed fittings, push fittings, or instant fittings (also known as “internal pressure” or “connection pressure”). Pressure connections are the most common, because it is easy to connect and disconnect different lines if needed.
Hose storage
To maintain a safe working environment and ensure that the hose is not damaged, they are often stored on spools or coils.
Air hose pulley
An air hose spool is a cylindrical spindle used to store a hose. They are usually mounted on a wall, ceiling or floor. They help to straighten the hose and avoid any complications. Often, they are retracted by a spring-loaded mechanism, but they can also be bent by hand. Air hose pulleys are commonly used in combination with pneumatic tools or any other application that requires only a temporary supply of compressed air. The hose is usually made of rubber, PU or PVC. The self-retracting hose mechanism works by pulling out the hose to the desired length. The hose ring vibrates when it opens, meaning you can lock it in place by releasing it. The hose must be pulled out slightly to activate the self-retracting spring mechanism. While squeezing, hold the hose until it is fully retracted. Never drop it while retracting as the end of the whip can cause injury or damage. The hose pulley has the advantage of automatically storing the hose and ensuring a tidy and safe working environment. This also prevents any premature damage to the hose due to wear, pulling or accidental collision with something in the environment (other tools, vehicle, etc.).
Twisted air hose
Screw air hoses are often used in garages and workshops to supply air to pneumatic tools such as impact wrenches, blow guns, etc. They are lightweight and retractable, so they do not take up much space. The hose is usually not coiled to the end of the connections. On either side is a small straight section called the tail. The difference between elongated and retracted depends on the diameter of the coil. For a standard coil air hose, the elongated length can be, for example, ten times the summed length. To produce a twisted air hose, the hose material must have a good elastic memory to return to its original coiled state after smoothing. Therefore, rubber is not used and nylon, PU or PVC are usually used for these applications.