Trelleborg debuts new hydrogen sealing product range

Trelleborg, Sweden – Trelleborg Sealing Solutions has launched a new rane of sealing materials, designed for the production, transport and storage; and end-use of hydrogen.

Unveiled last month during Hydrogen Tech Expo 2023 in Bremen, Germany, the  permeation-proof H2Pro materials are tailored to cope with very high pressures and low temperatures.

Such features enable seals to withstand rapid gas decompression, while also demonstrating “excellent wear and extrusion properties”, according to Trelleborg.

The range includes H2Pro EBT25 – a new EPDM for high-pressure environments across a wide range of temperatures – and Zurcon H2Pro ZLT – a “unique” TPU for very low temperatures.

With an important role in transition to carbon neutrality, hydrogen can be used both as a fuel source and as a storage medium for surplus energy from renewable sources.

However, due to its inherent molecular characteristics, the gas is difficult to seal, noted James Simpson, global segment director energy at Trelleborg.

The new material range, he said, offers reliable sealing across a range of applications, including pumps, valves, connectors, and other devices in the supply chain.

Challenges faced by the hydrogen industry include permeation and leakage, as hydrogen is the simplest element with the smallest molecular structure.

Another is rapid gas decompression (RGD), where hydrogen in a high-pressure system can be absorbed into a seal.

If the pressure in the system is suddenly relieved, gas trapped in the seal can expand, potentially causing the seal to blister and crack as the gas tries to escape.

Furthermore, seals for different hydrogen systems need to withstand high pressures, up to 1,000 bar/14.34 psi, and extremely low temperatures down to minus 250°C.

“Trelleborg is creating the materials and application-specific solutions to support every type of business involved in hydrogen,” Simpson commented.

Target markets, he said, include the energy generation, aerospace, off-highway, truck and bus, chemical transportation and marine industries.

Trelleborg uses “advanced testing rigs” to assess materials for oxygen and ozone aging, hydrogen compatibility, leakage, permeation and the ability to withstand RGD.

Zurcon H2Pro ZLT, continued the Swedish elastomer products maker, exhibits “very low permeability and displays a superior ability to withstand RGD”.

With a wide operating service temperature range and high extrusion and wear-resistance properties, the grade can be used in O-rings and U-cups for static sealing applications.

Meanwhile, H2Pro EBT25 is said to demonstrate “a superior ability to withstand RGD”, and features low permeability, a wide operating service temperature range and 85 Shore A hardness.

This material is suitable for O-rings for static sealing and custom moulded parts and frame seals for fuel cells and electrolysis equipment, stated Trelleborg.