Office Chair Gas Leak and Sinking

The root cause of an office chair sinking due to gas leakage is the failure of the gas spring (pneumatic rod), where the internal seal wears out, causing nitrogen gas to escape and resulting in a loss of locking force.

Fault Symptoms and Self-Inspection Methods

1. Typical Symptoms

   • Slow Automatic Sinking: The chair descends uncontrollably after sitting.
   • Weak Pressing Response: The seat feels soft, with slow rebound or no cushioning effect.
   • Gas Leak Sound: A hissing sound is heard while sitting still or operating the chair.
   • Seat Tilt: In severe cases, the chair tilts like a seesaw.

2. Three-Step Self-Inspection Method

   • Pressing Test: Quickly press down on the seat. If it goes all the way to the bottom without rebounding, there may be a gas leak.
   • Sitting and Listening: Remain still and listen for continuous gas leak sounds from the bottom of the chair.
   • Observation: Check if the chair sinks automatically or is noticeably uneven.

3. Other Possible Causes to Check

   • Inspect if the adjustment valve/locking mechanism is obstructed by foreign objects.
   • Confirm that the screws and bolts at the connections are not loose.
   • For electric height-adjustable chairs, check the power supply, circuitry, and motor.

Repair Methods and Precautions

1. Self-Replacement of the Gas Spring

   • Preparation Tools: Hammer (or adjustable wrench), lubricating oil, and a qualified new gas spring (must match specifications, preferably with SGS Level 4 certification, TUV certification, or compliance with GB/T 2280-2016 standards).
   • Operation Steps:
     1. Raise the chair to its highest position and turn it upside down, placing a soft cloth underneath for protection.
     2. Gently tap the edge of the central sleeve of the five-star base with a hammer to separate the base from the lower end of the gas spring (apply lubricating oil if rusted).

2. Replacing the Air Pump (Proceed with Caution)

   • Risk: The airflow during deflation can cause serious injury. It is recommended to contact a professional for repair. If attempting to do it yourself:
     1. Disassemble the chair and use a screwdriver to press the air needle of the gas rod until an air burst sound is heard, then test after complete deflation.
     2. If the gas leak persists, disassemble the gas rod to replace the air pump (installed between the stainless steel base and the steel plate).

Safety Hazard Warnings

1. Reduced Support Force: Gas rod leakage can cause the chair to tilt or wobble, increasing the risk of falls and potential injuries such as abrasions and sprains, especially for the elderly or those who are physically weak.
2. Sudden Failure Risk: The gas leak may worsen, leading to sudden and complete failure of the gas rod, causing the chair to collapse and potentially resulting in serious injuries such as spinal compression, fractures, or head impacts.
3. Other Injury Risks: When the chair is unstable, users may collide with surrounding objects while adjusting their posture or suffer muscle strains and joint dislocations due to body twisting. Using the chair at heights may also lead to fall injuries.