Metal or Plastic Liquid Cooling Connectors? What You Should Consider

This guest article from CPC  takes a look at the differences between metal and plastic liquid cooling connectors, the benefits and challenges to each, as well as what you should consider when making a decision on what material to use.

liquid cooling connectors

When trying to decide between metal or plastic quick disconnects, you should consider several factors such as pressure, temperature, flow rate, environmental exposure and chemical compatibility. (Photo: CPC)

Historically, metal has been the material of choice for its strength and durability for liquid cooling connectors. Fluid management systems in particular, consistently defaulted to metal. But despite its advantages, metal isn’t perfect. Its weight, cost and corrosion-susceptibility are all weaknesses that have prompted engineers and designers of mission-critical applications to look for alternative materials. Enter plastics.

In more recent decades, metal has been replaced by high-performance plastics in a wide-range of demanding applications including automotive, military avionics and life-support systems. Plastics are famous for their lighter weight and corrosion resistance, but modern high-grade plastics have even more to offer. They boast vastly improved strength and durability. They also allow for an array of fabrication options including machining, injection molding and 3D printing. These advanced plastics have found their way into the fastest growing segment of fluid management—liquid cooling.

As liquid cooling is increasingly deployed in high-performance computing and data center applications, engineers are looking for quick disconnects (QDs) purpose-built for their needs. Today’s high-performance thermoplastics can handle the pressure, temperature, shock and vibration challenges presented by demanding liquid cooling applications. Many liquid cooling users in high-performance computing and data centers are choosing to use polyphenylsulfone (PPSU), an engineered polymer that yields the mechanical, thermal and physical performance characteristics they need.

PPSU exhibits excellent tensile strength and creep resistance over broad temperature ranges—0°F to 240°F (-17°C to 115°C). The material is dimensionally stabile with low thermal expansion, withstands heat deflection temperatures of over 200°C, and, as a thermal insulator, reduces condensation on the connector and makes handling easier because it won’t be hot to the touch when warm fluid is present. PPSU is compatible with the majority of today’s most widely used cooling fluids including 3M Novec, DI water, glycols, mineral oils, and other engineered fluids. One of the most significant benefits of using PPSU in fluid management is eliminating the risk of corrosion.

Taken as a whole, PPSU is being used in liquid cooling QDs for the first time because it delivers the benefits of plastic—lightweight, cost-effective and non-corroding—with robustness comparable to metal.

When trying to decide between metal or plastic quick disconnects, you should consider several factors such as pressure, temperature, flow rate, environmental exposure and chemical compatibility. You’ll also need to examine ease of use, weight, cost, the ability to hot swap without risking leaks and robustness for long periods of connection.