Office Chair Sinking When Sitting

The sinking of an office chair when sitting is usually not a serious issue. It is mostly caused by air leakage in the gas lift, aging of the sealing ring, loosening of the adjustment mechanism, or poor-quality components in low-priced products. It can be resolved by checking the screws, adjusting the locking mechanism, replacing the gas lift, or using hose clamps/PVC pipes for temporary fixation. For complex issues, it is advisable to contact professional repair services.

Common Causes

1. Gas Lift Failure: Internal gas leakage or damaged parts result in insufficient support. High-quality gas lifts should be filled with nitrogen with a purity of 99.99%. If the gas purity is insufficient or the seal is not tight, sinking is likely to occur.
2. Aging of the Sealing Ring: After long-term use, the rubber sealing ring may wear out or age, leading to gas leakage and the inability of the chair to maintain its height.
3. Loosening of the Adjustment Mechanism: Components such as the base tray and locking screws at the bottom of the chair become loose, preventing the height from being locked even if the gas lift is functioning properly.
4. Issues with Low-Priced Products: Some low-priced adjustable chairs use inferior gas lifts and seals to reduce costs, significantly increasing the likelihood of sinking after a period of use.

Solutions

1. Check and Tighten the Screws: Turn the chair upside down and check if the adjustment screws and the connection to the gas lift at the bottom are loose. Tighten them one by one with a screwdriver or wrench and then test.
2. Adjust the Locking Mechanism: If the screws are not the issue, check if the locking mechanism is stuck or misaligned. Adjust it appropriately and then test the lifting function.
3. Replace the Gas Lift: If the gas lift is confirmed to be damaged, it needs to be replaced with a new one. First, apply lubricating oil to the seams, then use a pipe wrench or hammer to assist in disassembly, taking care not to damage the base plate.
4. Temporary Fixation Methods:
   • Hose Clamp Method: Adjust the chair to the desired height and wrap a hose clamp around the cylinder. Enhance the friction by using a rubber band or sandpaper for polishing, then tighten the clamp and test. If the height is incorrect, move the clamp up or down for adjustment.
   • PVC Pipe Method: Measure the diameter of the cylinder and its length at the desired height. Purchase a matching PVC pipe and split it lengthwise, then fit it over the cylinder and secure it. Wear a mask when cutting to avoid inhaling particles.

Seeking Professional Help

If the issue involves replacing the gas lift, aging of the sealing ring, or structural damage, it is recommended to contact the merchant or a professional repair technician. Self-repair requires certain tools and skills, and improper operation may damage the chair. If the chair is still under warranty, contact after-sales service first.