Lightweight pipes for the aviation industry

Pipes made of high-performance thermoplastics by PFW Aerospace
Pipes made of high-performance thermoplastics by PFW Aerospace
Passengers have no idea that a maze of pipes more than three kilometers long is running through wide-bodied aircraft like the A350. What flows through them is everything that the aircraft needs technically and makes the flight pleasant: fuel, hydraulic fluid, hot air, fresh water, waste water, oxygen and coolants. PFW Aerospace GmbH, based in Speyer, Germany, is an expert in such piping systems – and is set to revolutionize the field with new, lightweight materials.

The demands on pipes in airplanes are high: the space is tight, some of the pipes are bent over 180 degrees. The temperatures fluctuate between minus 65 °C and plus 250 °C. In hydraulic applications, they must also be able to withstand extreme pressures of over 17,400 psi. So far, it has been possible to withstand these stresses almost exclusively with some heavy metallic materials such as steel, aluminum and titanium.

Lightweight construction of piping systems

PFW Aerospace is no longer satisfied with this situation. In a research project lasting several years, the company, together with partners, has developed new processing methods for extremely resilient plastic pipes to be able to replace metallic pipes in many places. So-called high-performance thermoplastics are used here. These materials are not only significantly more heat-resistant than previous plastics, but are also resistant to aggressive liquids such as kerosene or hydraulic fluid.

But most importantly, the plastic pipes are up to 40% lighter than metallic pipes. An enormous savings potential that also benefits the environment, because every gram of weight saves fuel and reduces CO2 emissions – another example that ecological and economic goals in the aviation industry are congruent.

Joint investment

The new processing methods for high-performance thermoplastics were developed as part of a project funded by the Federal Aviation Research Program. In addition to PFW, other industry partners and research institutions of the TU Kaiserslautern were also involved. PFW has since invested a seven-figure sum in new production facilities.

The first lightweight pipes have been in use in the A350 since 2014. There they remove liquids from the cargo hold – for example when snow melts on the cargo. But this is only the beginning. PFW is currently working to ensure that fresh and waste water pipes made of high-performance thermoplastics will soon go into series production. In the long term, these plastics will be able to replace almost all pipes in aircraft with additional modifications.