In the design of gas springs, the choice of filling medium is directly related to the performance, life and safety of the product. Nitrogen (N₂) and compressed air are the two most common options, but there are significant differences between the two in pressure stability, temperature resistance and cost. This article will explore the scientific logic behind this key technology choice and reveal the industry's best practices.
First. Core differences in inflatable media
Gas springs generate elastic force through compressed gas in a sealed cylinder. The physical properties of the medium determine its applicable scenarios:
| Characteristics | Nitrogen (N₂) | Compressed air |
| Chemical stability | Inert gas, almost no reaction with other substances | Contains 21% oxygen, which may oxidize the internal oil film |
| Humidity effect | Absolutely dry | May contain moisture, causing condensation corrosion |
| Coefficient of thermal expansion | Low (small pressure fluctuation when temperature changes) | High (pressure fluctuates significantly with temperature) |
Second. Pressure stability: the overwhelming advantage of nitrogen
1. The challenge of temperature change
According to the ideal gas equation (PV=nRT), gas pressure is proportional to temperature. Nitrogen has a more linear pressure change at extreme temperatures due to its stable molecular structure:
- High temperature (>60℃): Air may accelerate the aging of sealing materials due to the active oxygen; nitrogen remains stable.
- Low temperature (<-20℃): Water in the air freezes, causing damping failure; nitrogen does not have this risk.
2. Reliability in long-term use
After 10,000 cycles of testing, the pressure decay of nitrogen-filled gas springs is less than **5%**, while the decay of air-filled products is **12%-15%** (test standard: ISO 11901).
Third. Temperature resistance: the life and death line in extreme environments
Comparison of applicable temperature ranges of gas springs of different media:
- Nitrogen spring: -50℃ to +150℃ (such as spacecraft solar panel support mechanism).
- Air spring: -20℃ to +80℃ (common in low-cost furniture applications).
Fourth. Balancing cost and technology
Despite the superior performance of nitrogen, compressed air has not been completely eliminated for the following reasons:
1. Cost difference: Nitrogen filling requires additional purification equipment, and the unit cost increases by **8%-12%**.
2. Low-end market demand: Air springs are still cost-effective in scenarios that are not sensitive to temperature differences (such as indoor furniture).
Guangzhou Tieying Spring Technology Co.,Ltd set up in 2002,focusing on gas spring production for more than 20 years,with 20W durability test,salt spray test,CE,ROHS, IATF 16949.Tieying products includes Compression Gas Spring, Damper, Locking Gas Spring, Free Stop Gas Spring and Tension Gas Spring. Stainless steel 3 0 4 and 3 1 6 can be made. Our gas spring use top seamless steel and Germany Anti-wear hydraulic oil, up to 9 6 hours salt spray testing, - 4 0℃~80 ℃ Operating temperature, S G S verify 1 5 0,0 0 0 cycles use life Durability test.
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Post time: May-17-2025