Avoiding Gas Leakage Through Effective Sealing Systems

This article was contributed by:

Christoph Meissner
Market Unit Manager
Parker Engineered Materials Group
Prädifa Technology Division

Parker Prädifa's GS Rod Seal for gas spring applications

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How can effective sealing systems prevent gas leakage?

April 17, 2025

Gas leaks are a significant problem that both pollutes the environment and causes economic damage. It is estimated that leaks from gas networks account for up to 3% of global greenhouse gas emissions. This figure illustrates how even small leaks can add up to significant environmental damage. It is therefore crucial to invest in high-quality sealing systems to achieve both environmental and economic benefits.

Why is leakage a problem?

Leaks not only lead to increased greenhouse gas emissions, but can also result in costly business interruptions and damage to equipment or even people. Companies that invest in effective sealing systems can not only improve their environmental footprint, but also reduce their operating costs. High-quality sealing systems minimize the risk of leakage and thus contribute to the efficiency and safety of processes.

What factors influence leakage?

The leakage of a sealing system is influenced by various factors:

Medium: Whether gas or liquid, the properties of the medium are decisive. Gases with small molecule sizes, such as hydrogen, are more volatile than those with larger molecules. This means that they can diffuse more easily through seals.
Temperature: Higher temperatures usually result in lower viscosity of the medium to be sealed, which can affect leakage. An increase in temperature can accelerate the movement of molecules and therefore increase the likelihood of leakage. Very low temperatures can also have an influence on leakage, as the sealing material loses its flexibility.
Pressure: The pressure in the system plays a significant role in the tightness.
Sealing surfaces: The condition of the sealing surfaces is crucial. Unevenness can significantly impair the tightness.

Types of leakage

There are two types of leakage:

Permeation: This type of leakage occurs when the medium diffuses through the sealing material. Permeation is highly dependent on the solubility of the medium in the sealing material and the temperature.
Interface Leakage: This form of leakage occurs along the sealing surface due to small microchannels. Even optically smooth surfaces can exhibit unevenness that impairs the tightness.

Design recommendations to prevent gas leakage

To reduce leakage, especially with gaseous media, the following design recommendations are important:

Seal cross section: A larger seal cross-section creates larger contact surfaces, which reduces interface leakage. A larger seal can seal unevenness better.
Compression rate: A high compression rate ensures that unevenness in the sealing surface is reliably sealed by the elastomer material. This is particularly important with volatile media.
Groove fill: A high groove fill reduces the area of the seal facing the medium, which reduces permeation. However, excessive groove filling can increase the risk of groove overfilling.
Manufacturing accuracy of the groove: High manufacturing accuracy and low tolerances are crucial to minimize mechanical stress on the sealing system. Precise manufacturing improves tightness and extends the service life of the system.
Sealing areas: Smooth sealing areas with minimal unevenness are crucial for tightness. Any machining marks in the sealing surfaces should ideally be aligned with the sealing line and not run across it.

Seal characteristics

The characteristics of the seals are also crucial:

Permeation characteristics: Different types of elastomers have different permeation properties. Materials such as FKM and butyl generally provide a better barrier to gases than silicone.
Compression set: The ability of the sealing material to retain its elasticity and strength over the years is crucial for long-term tightness. Materials must also function reliably under changing conditions.
Media resistance: The chemical resistance of the seal material has a significant impact on the service life and the leakage rate. Chemical attack can lead to accelerated aging.
Hardness: The hardness of the material can influence the leakage rate. Harder materials withstand mechanical influences better, while softer materials can compensate for unevenness better.

Conclusion

The correct design of sealing systems plays a crucial role in preventing gas leakage. By taking the various influencing factors into account and selecting suitable seal materials and designs, companies can not only protect the environment but also reduce costs. Investments in high-quality sealing systems pay off both ecologically and economically. Parker Prädifa offers solutions that help overcome these challenges and promote a sustainable future.