The difference between polyurethane pipe and polyethylene pipe and how to choose

           In the industrial field, the selection of pneumatic components is crucial, and the performance of pipes, as an important part of the pneumatic system, directly affects the stability and efficiency of the system. As an agent of SMC and the ATG brand that cooperates with many suppliers, we often encounter customers asking about the difference between polyurethane pipes (PU pipes) and polyethylene pipes (PE pipes), and which one is better in practical applications. Next, we will analyze these two pipes in detail from multiple aspects to help you make a more appropriate choice.

1、Materials and basic properties

（1）Polyurethane tube (PU tube)

          Polyurethane tubes are made of polyurethane material, which has the characteristics of an elastomer and combines the advantages of plastic and rubber. Its molecular structure contains hard segments and soft segments, with the hard segments providing strength and rigidity and the soft segments providing elasticity and flexibility.

（2）Polyethylene pipe (PE pipe)

          Polyethylene pipes are made of polyethylene resin through extrusion molding. Polyethylene is a thermoplastic resin with a simple linear molecular structure. It can be divided into low-density polyethylene (LDPE), medium-density polyethylene (MDPE) and high-density polyethylene (HDPE) according to its density.

2、Physical performance comparison

（1）Hardness and flexibility

           Polyurethane tubes have a wide range of hardness, usually between 80-95 Shore A hardness, and have good flexibility and elasticity. They can be bent to a certain extent without damage, and are suitable for use in situations that require frequent movement or vibration. For example, in the connection of pneumatic tools, PU tubes can bend flexibly with the movement of the tool, reducing the risk of breakage due to excessive rigidity.

           The hardness of polyethylene pipe is relatively low, generally around 40-50 Shore D hardness, which makes it more flexible and easy to bend, but not rigid enough. This makes PE pipe perform well in some scenarios that require soft pipes to adapt to complex installation environments, such as pipe layout in narrow spaces.

（2）Heat resistance

           The temperature resistance range of polyurethane tubes is usually between -20℃ and +60℃, and some specially formulated PU tubes can withstand higher temperatures, up to around +80℃. Within this temperature range, PU tubes can maintain good performance and will not show obvious hardening or softening due to temperature changes.

           The temperature resistance range of polyethylene pipes is relatively narrow, generally -40℃ to +60℃. Low-density polyethylene has a lower upper temperature resistance limit, while high-density polyethylene has slightly better temperature resistance. Although PE pipes show good impact resistance in low-temperature environments, long-term use in high-temperature environments may cause deformation or performance degradation of the pipe.

（3）Compressive strength

          Polyurethane tubes have high compressive strength and can withstand high working pressures, generally between 0.5-1.0MPa, and some high-pressure PU tubes can withstand pressures as high as 1.5MPa. This makes PU tubes suitable for pneumatic systems with high pressure requirements, such as cylinder drive lines.

          The compressive strength of polyethylene pipes is relatively low, and the working pressure is usually between 0.3-0.6MPa. It is mainly suitable for low-pressure pneumatic systems or for conveying gas, liquid and other media. Under high-pressure environments, PE pipes are prone to expansion or even rupture.

3、Chemical performance comparison

（1）Corrosion resistance

         Polyurethane tubes have a certain degree of corrosion resistance to general oils, fats, solvents, etc., but are less resistant to corrosive media such as strong acids, alkalis, and strong oxidants. In a pneumatic system containing oil mist, PU tubes can work stably, but if they come into contact with highly corrosive liquids, they may age or be damaged.

         Polyethylene pipes have excellent corrosion resistance, hardly react with any chemical substances, and have good resistance to corrosive media such as acids, alkalis, and salts. This makes PE pipes widely used in industries such as chemicals, medicine, and food that require high corrosion resistance, such as transporting corrosive liquids or gases.

（2）Aging resistance

          During long-term use, polyurethane tubes may age due to the influence of ultraviolet rays, oxygen, temperature and other factors, which may manifest as the tube becoming hard, brittle, darker in color, etc. Therefore, when PU tubes are used outdoors or in direct sunlight, certain protective measures need to be taken, such as installing a protective cover.

          Polyethylene pipes have good aging resistance, especially high-density polyethylene, which has a long service life. Under normal use conditions, PE pipes can work stably for a long time without excessive maintenance.

4、Application scenario comparison

（1）Application of polyurethane tube

          Since polyurethane tubes have good flexibility, compressive strength and oil resistance, they are widely used in pneumatic systems, hydraulic systems, automation equipment, machinery manufacturing and other fields. For example, in the pneumatic conveying system of the factory, PU tubes are used to connect air compressors, cylinders, solenoid valves and other components to achieve gas transmission; in the automobile manufacturing industry, PU tubes can be used for pipeline connections in brake systems, suspension systems and other parts.

（2）Application of Polyethylene Pipe

          Polyethylene pipes are mainly used in the fields of chemical industry, medicine, food, agricultural irrigation, water supply and drainage due to their excellent corrosion resistance, flexibility and low temperature resistance. In the chemical industry, PE pipes are used to transport various corrosive liquids and gases; in the food industry, PE pipes meet hygiene standards and can be used for material transportation in food processing; in agricultural irrigation, PE pipes are suitable as pipes for drip irrigation and sprinkler irrigation systems due to their flexibility and low temperature resistance.

5、How to Choose: Which is Better?

         So, which one is better, polyurethane pipe or polyethylene pipe? This needs to be considered comprehensively according to the specific application scenarios and needs.

         If your application scenario has high pressure requirements, requires the pipe to have good compressive strength and elasticity, and the medium contains substances such as oil, then polyurethane pipe is a better choice. For example, in pneumatic tools and high-pressure pneumatic systems, PU pipes can meet working requirements and ensure stable operation of the system.

         If your application scenario has high requirements for corrosion resistance, requires the pipe to be used in corrosive environments such as acid, alkali, and salt, or requires soft pipes to adapt to complex installation environments, then polyethylene pipes are more suitable. For example, in the fields of chemical transportation, food processing, agricultural irrigation, etc., PE pipes can play their advantages and extend their service life.

         As an agent of SMC and a partner of ATG brand, the polyurethane tubes and polyethylene tubes we provide are all from high-quality suppliers with reliable quality and performance. SMC's polyurethane tubes are widely recognized in the field of industrial automation for their high precision, high reliability and good temperature resistance; ATG brand polyethylene tubes are excellent in corrosion resistance and low temperature resistance, meeting the needs of different industries.

         In short, the key to choosing polyurethane pipe or polyethylene pipe is to clarify your application requirements, including working pressure, temperature range, medium properties, installation environment and other factors. If you encounter any problems during the selection process, please feel free to contact us and we will provide you with professional technical support and solutions.