Quick Answer: A gas spring losing pressure is primarily caused by seal degradation, piston rod scratches, extreme temperature exposure, or side-loading misalignment. Because these components rely on high-pressure nitrogen gas…
If you are operating industrial machinery, automotive hoods, medical equipment, or heavy-duty hatches, you probably rely on gas springs (also known as gas struts) for smooth, controlled lifting and counterbalancing. However, like any mechanical component under constant stress, gas springs don’t last forever. One day, you might notice that a lid feels heavier to lift, or a hatch fails to stay open entirely.
When a gas spring fails, it is almost always due to a loss of internal pressure. But why does this happen, and more importantly, how can you prevent it from cutting your equipment’s lifespan short?
In this comprehensive guide, we will break down the mechanics behind gas spring pressure loss, explore the root causes, and provide actionable engineering best practices to keep your operations running smoothly.
Understanding the Anatomy of a Gas Spring Failure
To understand pressure loss, we first need to look at how a gas spring is built. Inside the cylinder, a precisely measured volume of nitrogen gas is compressed to a high pressure (often exceeding 100 bars). This pressure pushes against the piston rod, creating the extending force.
The only thing keeping that immense pressure contained is a set of specialized internal seals and guide bushings. If that sealing system is compromised—even by a fraction of a millimeter—the nitrogen gas will slowly bleed out.
Here are the four most common culprits behind premature gas spring pressure loss:
1.
Natural Seal Degradation and Aging
The internal seals of standard gas struts are typically made from elastomers like NBR (Nitrile Rubber) or Polyurethane. Over years of service, these materials naturally lose their elasticity, become brittle, or crack. Friction from thousands of cycles gradually wears down the seal lips. Once the material degrades, it can no longer maintain a gas-tight grip around the moving piston rod.
2.
Piston Rod Damage: The Silent Killer
The surface of a gas spring’s piston rod must remain incredibly smooth and pristine. Unfortunately, during harsh industrial operations or improper installation, rods often fall victim to:
Scratches and Dents: Dropping tools on the rod or using pliers directly on the shaft creates microscopic gouges. Every time the rod retracts into the cylinder, these sharp imperfections act like tiny knives, tearing the internal rubber seals.
Environmental Contamination: Airborne dust, grinding grit, or paint overspray can settle on the rod. If the rod is not protected, these particles get dragged directly into the sealing mechanism, causing rapid, abrasive wear.
3.
Extreme Ambient Temperatures
Gas springs are highly sensitive to thermal environments. Standard units are engineered to operate comfortably between -20°C and +80°C.
High Heat: Excessive ambient heat increases the internal pressure of the nitrogen gas, putting immense strain on the seals. Furthermore, prolonged heat accelerates the chemical aging of the rubber components.
Extreme Cold: Conversely, intense freezing temperatures cause the rubber seals to stiffen and contract. When the seal loses its flexibility in the cold, a phenomenon known as “cold leaking” occurs, allowing gas to slip through the micro-gaps.
4.
Side Loading and Misalignment
Gas springs are strictly designed to handle axial forces—meaning forces that push and pull in a perfectly straight line. If the
mounting brackets are misaligned, or if the moving application twists during operation, the gas spring experiences side loading. This lateral force pushes the rod sideways against the guide bushing, creating an uneven gap in the seal on the opposite side, which leads to immediate gas evacuation.
Technical Overview: Operating Conditions vs. Lifespan
| Operational Factor |
Primary Impact on the System |
Expected Lifespan Outcome |
| Proper Installation (Rod Down) |
Continuous oil lubrication of the main seal |
Maximum Lifespan (30,000 to 50,000+ cycles) |
| Side Loading & Misalignment |
Uneven guide wear and distorted seals |
Severe Failure (Lifespan reduced by up to 80%) |
| Abrasive Dust/Dirt Exposure |
Scratched rod surface and torn internal seals |
Rapid Degradation (Failure within a few weeks) |
| Continuous High Heat (>80°C) |
Hardened rubber compounds and gas expansion |
Permanent Pressure Drop over a short period |
Proactive Prevention: How to Maximize Gas Spring Lifespan
While gas pressure loss is inevitable at the very end of a product’s life cycle, premature failure can easily be prevented. At Newtone Gas Springs, we build our
products to high technical standards, but implementing these simple engineering practices will significantly extend the service life of your components even further:
Always Mount Rod-Down: This is the golden rule of gas spring maintenance. In its resting position, a gas spring should always be oriented with the piston rod pointing downward. This design allows the internal oil to pool right above the main seal, keeping it continuously lubricated, flexible, and perfectly sealed.
Protect the Shaft at All Costs: Never paint, tape, or grease the piston rod yourself. If your application operates in a dusty environment, outdoors, or near welding stations, equip your gas springs with protective plastic sleeves or rubber bellows (boots) to shield the rod from debris.
Eliminate Misalignment: Double-check your mounting geometry. If your application has a slight wobble or flexible frame, switch from rigid eyelet end-fittings to ball joints. Ball joints allow for a few degrees of angular pivot, absorbing minor misalignments and eliminating destructive side loads.
Specify the Right Seal for the Job: If you know your machinery will operate in high-temperature zones or around harsh chemicals, do not settle for standard NBR. Request custom gas springs built with Viton (FKM) seals, which offer far superior thermal and chemical resistance.
Frequently Asked Questions
Can you manually repressurize a failed gas spring?
No. Standard industrial gas springs are completely sealed, self-contained units. Once they lose their gas pressure, they cannot be safely refilled or repaired without specialized factory machinery. Attempting to drill or modify a gas spring is extremely dangerous due to the high residual internal pressure. The component must be replaced.
Why do my gas springs feel weaker during the winter?
This is a direct result of physics (Gay-Lussac’s Law). Gas pressure naturally decreases as the temperature drops. As a general rule of thumb, a gas spring will lose approximately 3.5% of its output force for every 10°C drop in temperature. If the force returns when the weather warms up, the seal is intact. If it remains weak, the unit has permanent pressure loss.
Conclusion
A
gas spring losing pressure is rarely a random occurrence; it is usually a direct symptom of environmental stress, mechanical misalignment, or natural seal wear. By understanding the critical importance of proper rod orientation, preventing rod contamination, and choosing the correct seal materials for your specific environment, you can drastically reduce downtime and ensure your lifting systems operate safely for years to come. Investing a little time into correct installation geometry today prevents costly component replacements tomorrow.
Need the Right Gas Spring Solution for Your Application?
At Newtone Gas Springs, we engineer and manufacture high-performance, durable gas springs designed to withstand the most demanding industrial environments. Whether you need a standard replacement or a custom-engineered solution tailored to your specific technical requirements, our team of experts is here to guide you.
Don’t let unexpected equipment downtime slow your operations down.
Contact our Newtone engineering team today to discuss your project requirements, request a technical quote, or browse our comprehensive product
catalog. We are ready to provide the reliable support your machinery deserves.
