Durability, Safety, Corrosion Resistance: Advantages of PPSU Fittings for Water Distribution Systems

The EU's revised Drinking Water Directive, passed into national legislation of the Member States in 2023, ensures that Europeans benefit from some of the highest water quality standards in the world. However, the Directive has also made waves in the plumbing industry as the requirements for materials that come into contact with potable water have been tightened further. With the new, lower lead limit in tap water, PPSU fittings have emerged as an increasingly popular alternative to brass for safe and reliable drinking water systems.

We talked with Stephan Müller, Pipelife's Business Development Manager for Water Distribution and Supply, about the impacts of the Directive and how plumbers can preserve their competitiveness while meeting both customers' expectations and revised water safety norms.

_{Use of PPSU fittings in hot and cold water distribution systems}

PPSU (polyphenylsulfone) is a high-performance, medical-grade thermoplastic material that has been used in healthcare, food service, aviation and other industries for decades. PPSU has higher heat resistance than most plastics, and it demonstrates excellent impact strength and resistance to fatigue and cracking.

In modern water distribution systems, PPSU fittings have become a go-to solution due to their hygienic safety, mechanical and corrosion resistance, and light weight. Their ability to withstand high pressure and temperatures is essential for plumbing systems to remain durable and leak-free.

Even before the revised Directive, PPSU fittings were widely used in countries such as Germany and Austria, where legal requirements and customer expectations for drinking water quality are particularly stringent.

_{Key advantages of PPSU fittings}

_{Chemical inertness}

PPSU is a biologically inert, non-toxic and entirely heavy-metal-free material, meeting even the most stringent potable water quality standards. Furthermore, PPSU exhibits high resistance to chemical disinfectants, making it ideal for plumbing systems in laboratories, hospitals, hotels and other facilities where strict disinfection regimes may be required.

_{Corrosion resistance}

PPSU is inherently corrosion-proof, even surpassing metal alloys. PPSU fittings are also less prone to scaling compared to brass alternatives. The material can be safely used in plumbing systems irrespective of the water hardness.

"The corrosivity of water in Europe varies a lot; for example, the Nordic countries have soft water, which tastes nicer, but poses challenges to plumbers due to corrosion issues. PPSU fittings can be used with a broader range of drinking waters regardless of their corrosivity," explains Stephan Müller, Pipelife's Business Development Manager for Water Distribution and Supply.

_{Pressure and mechanical resistance}

PPSU demonstrates high strength and excellent impact and creep resistance; thus, the material is highly suitable for pipe-to-pipe fittings. If installed correctly, PPSU fittings reliably serve for at least 50 years, matching the lifetime of a building. For some applications, where extremely high mechanical resistance is needed (such as threaded fittings), metal alloys should be used.

_{Temperature resistance}

PPSU fittings are suitable for hot drinking water and heating systems. The material has been widely tested in various industries and found to tolerate short-term temperature spikes even above 200 °C.

_Weight

PPSU fittings are considerably lighter than metal alternatives. Their light weight can make transportation and on-site handling easier, reducing installation time and effort, especially for large-scale plumbing setups in multi-storey or high-rise buildings.

_{Material costs}

While more expensive than commodity plastic alternatives (such as PP or PB), PPSU fittings remain considerably cheaper than those made of lead-free metal alloys, helping keep overall plumbing system costs competitive and affordable for customers.

_{Searching sustainable material alternatives: PPSU vs. brass fittings}

Brass fittings have traditionally been used in water distribution systems due to their affordability and good mechanical properties; however, cost-efficient, fully lead-free alternatives are available.

"PPSU has high impact strength, excellent heat- and chemical resistance, as well as long-term hydrolytic stability and biological inertness, making it a trusted material in multiple applications, including water distribution," Müller explains.

In fact, Pipelife has already been offering PPSU fittings for its popular RadoPress multilayer composite pipe system. In response to increasing customer interest and demand, the fitting range has now been enlarged, comprising more than 30 PPSU fittings in DIM 16-32.

_{Installation considerations of PPSU fittings}

In terms of installation, there are no major differences between plastic and metal press fittings. If anything, their lower weight can make PPSU fittings easier to work with. When installed correctly, PPSU fittings provide secure, leakage-free connections throughout their lifetime and have minimal maintenance needs.

Pipelife's PPSU fittings are installed using commonly available TH- and U-profile press jaws without the need for specific tools, solder, flux or glue. Due to three inspection windows, any pipe insertion errors can be immediately noticed and fixed before pressing the connection, saving time, costs and effort on addressing errors later.

_{Combining the best of both worlds}

The revised Drinking Water Directive does not mean metals no longer have a place in our water distribution networks. Müller emphasizes that lead-free metal alloys are available and, despite their elevated costs, have advantages in certain applications:

"Lead-free metals should be used for threaded fittings, as these connections require very high mechanical strength. However, such strength is not needed for pipe-to-pipe fittings, where PPSU offers higher cost-efficiency and corrosion resistance."

Pipelife's newly expanded RadoPress portfolio features an array of both lead-free brass and PPSU fittings, offering a wide range of top-quality connections for various installation scenarios. The expanded fittings catalog allows plumbers to provide optimal water distribution system safety and reliability for their customers while remaining competitive in a rapidly changing market.

"By combining the advantages of high-performance organic materials and lead-free alloys, we have created a portfolio that ticks all the boxes — and we are proud to bring it to our customers."

The expanded product portfolio features coupler, reducer, elbow and tee PPSU fittings as well as a wide range of fittings from silicone bronze, simplifying hot and cold water distribution system design and installation. The fittings are manufactured in Germany and meet the leading quality standards.

With changing legislation and growing customer expectations, plumbing professionals search for new technologies and products that offer high hygienic safety, durability and ease of use while remaining cost-effective.

The corrosion resistance, light weight, and easy installation of PPSU fittings make them an excellent choice for today's evolving plumbing needs, helping ensure that every connection is secure and every system is built to last.