The Structure And Safety of Office Chair Gas Lift

The introduction of Adjustable Office Chair

Adjustable office chair is a general term. And it refers to a swivel chair whose surface height can be adjusted up and down and the seat surface can rotate horizontally. Therefore, people usually call it by names such as swivel lift chair, swivel chair, computer chair, office chair, desk chair etc. Since there is a lifting device for adjusting the height under the seat surface of this kind of chair, the seat can be raised and lowered. 

According to the type of lifting device used, pneumatic or hydraulic, the adjustable office chair is divided into 2 kinds: #pneumatic adjustable office chair and #hydraulic adjustable office chair.

Compared with the expensive hydraulic adjustable office chair with a relatively complex structure and a less sensitive height adjustment, the pneumatic one has the characteristics of low cost, simple structure, flexible operation, etc. Therefore, the pneumatic is popular among consumers. Besides, it is estimated that more than 80% of office buildings and companies are using pneumatic chair lifts.

Pneumatic gas lift

There is an gas cylinder in the pneumatic adjustable office chair. And the piston pneumatic rod in the gas cylinder moves up and down to control the lifting of the chair. Regular chair gas cylinder manufacturers use nitrogen to fill it. The concentration is generally above 99% with one or two barometric pressure.

Under normal circumstances, this pneumatic gas lift similar to a bicycle pump is filled with high-purity inert gas nitrogen. When a person sits on a chair, although the pressure of the nitrogen gas is increased by the squeezing, it is still within the limit range of the air pressure expansion, and no problem will occur.

However, some inferior pneumatic gas lift often have problems like insufficient nitrogen purity and shoddy material. In the case of high temperature in summer or frequent seat lifts, the pressure inside the gas lift will rise sharply, which may easily cause an explosion. In fact, there’re some unethical manufacturers using free high-pressure air instead of inert gas to keep costs down, which is more likely to cause the explosion of gas lift.


Structural safety standards for Office Chair

Generally, international agencies have comprehensive and strict standards for office and home chairs. Such as:

  • United States “General Requirements for Office Chairs”, “Small Office/Home Office Furniture” and other standards
  • The European Union’s “Office Chair Safety Performance Requirements”, “Office Chair Safety Test Methods”, “Office Chair Performance Requirements and Test Specifications” and other standards.

These standards stipulate many strict test methods and technical indicators, so the products meeting these standards is often of high quality.

At the same time, many countries have also stipulated certification systems for such products. And only products that meet the certification conditions and pass the test can be imported and sold.

For example, office furniture entering Germany generally has to pass GS certification (safety certification). This certification is very strict. If a product fails and causes an accident, the manufacturer will be subject to strict German (Europe) Product Safety Law. Ensuring product safety is of great significance.

Principle analysis and preventive measures on the explosion of Adjustable Office Chair

structure of gas lift


When the adjusting rod is pulled up by the tilt mechanism, the switch bolt is opened. The upper end of the piston and the lower end are connected with high-pressure nitrogen with the same pressure. However, the effective area of the upper end of the piston is larger than the lower end, the force is equal to the pressure multiplied by the effective area.

Thus, the upper end of the piston acts on the lower end, the cylinder raises, which in turn raises the seat. When the adjustment stem is reset, the switch bolt is closed, and a closed space filled with nitrogen is formed at the upper end of the piston to meet the downward pressure of the seat. When the seat is too large, the upper cylinder of the piston will explode or the switch bolt guide rod will fly out.

there are more photo and video of about the chair gas cylinder in the following link:

office chair cylinder,

Customized gas cylinders

Reasons for the chair explosion:

  • The nitrogen purity in the gas lift is insufficient, and it may explode in the high temperature environment or in the circumstancesof frequent
  • The container wall of the gas lift is not strong enough or made of poor material, an explosion may occur.
  • The sealing is not tight, causing gas to burst.

It is recommended that when choosing a lift swivel chair, you must choose formal products through formal channels to protect your own legitimate rights and interests.


If the wall of the gas lift is too thin, the base of the chair is relatively rough. Also the chairs often moves up and down with friction back and forth, forming an incision. It itself is very thin, and the friction makes the seat thinner, which will naturally cause explosion as time go by.

The gas lift is classified into class 1 to 5 and 5 class is the most stronger one.

To prevent the chair from exploding, manufacturers can either increase the thickness of the tube wall or improve the design of the bottom of the chair. At least one of them must be improved, and the probability of explosion will reduce. If both are improved at the same time, the probability of explosion will be almost reduced to zero.

Once you feel something is wrong, you need to replace it, meanwhile the daily maintain is necessary.




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