Why Do Gas Springs Lose Pressure? How Long Do They Last?

A gas spring is a sealed pressure vessel: the nitrogen inside can only escape between the rod and the tube through one component — the seal. Almost every failure we describe as "it lost its gas" begins at this single point, the seal-to-rod contact. Answer the question of what kills the seal, and you have answered the question of gas spring service life.

The five real causes of leakage

• Scratches and corrosion on the rod surface. The seal runs on the rod at micron-level precision. The slightest damage — dust, burrs, a stone chip or moisture-induced corrosion — files away at the seal on every stroke. In dusty environments, the dust cover (TK) exists for exactly this purpose.
• A dry seal. If the gas spring is mounted rod-up, or stored that way, the oil in the body flows away from the seal; the seal runs dry and hardens. The rule is simple: rod down.
• Side load and misalignment. If the axes are out of line, the rod bears against one side of the seal as it works. The risk is greatest with rigid (threaded) connections; wherever binding is possible, use a ball-stud.
• Paint, thinner and chemical contact. Paint or solvent reaching the rod chemically degrades the seal lip. If painting is done with the gas spring installed, the rod must be masked without exception.
• Exceeding the temperature limits. The standard operating range is −30 to +80 °C. Locations next to an oven or above an engine consume seal life rapidly; these applications require special seals — state them before ordering.

Service life: let's talk in cycles

A correctly selected and correctly mounted gas spring completes tens of thousands of cycles without trouble, depending on the application. End of life is not a sudden burst but a gradual loss of force: the practical criterion is F1 dropping more than 10% below its initial value. If the lid "doesn't stay up like it used to", have it measured — and in twin systems, always renew both gas springs together.

If leakage complaints keep recurring in your application, the problem is usually not the product but the mounting geometry or the operating environment — send us a photo of the application and let's look at it together. For a new product, the configurator will suggest the right size group and end fitting.