Since most employees spend a good amount of time seated in front of a computer these days, the comfort and ergonomic support of a good office chair can be a subtle but important contributor to one’s health. Modern office chairs have a number of features that can be used to customize the seat to an individual’s preferences. This allows one model of office chair to suit a number of desks, tables and users. The most important aspect is control of the height of the seat, but often, the back of the chair and even the armrests can be adjusted for optimum support.
Hydraulic and Pneumatic Chair Basics
Most standard office chairs are controlled by a hydraulic or pneumatic lift mechanism that allows the users to move the seat up and down to suit their body shape and desk setup. The height of the chair is normally controlled using a lever below the chair. When the lever is pulled to one position, the lift mechanism of the chair propels the chair to its top height. The users can then sit their weight into the chair until it’s the proper height and then release the lever mechanism to stop the chair seat in that position.
Hydraulic and pneumatic chairs both use the same principles to move the chair seat, but the mechanism is different. A hydraulic seat lift uses an incompressible liquid like an oil to propel the seat upward, while a pneumatic chair uses compressed air. In both cases, it’s the force of the internal pressure of the fluid that pushes the chair upward when the lift lever is pushed into the correct position. In a hydraulic chair, there are two chambers: one is expandable, and the other chamber contains the fluid under pressure that expands the first, thus causing the chair to rise.
Is an Office Chair Sinking?
Because office chairs have moving parts, they can wear out over time. This will become evident as the seat of the chair slowly sinks over time and will not maintain the desired height. The first thing to check if this happens is the mechanism attached to the lever that can be used to control the height of the chair. Sometimes, this external mechanism needs to be cleaned or oiled.
Internal Cylinder Replacement
If that isn’t the case and the chair is older or has been used frequently, the internal cylinder may need to be replaced. This can be done at home with a few tools by anyone who is handy, but it can also be done by an expert at a home or office store. Office chair repair parts can be purchased from the manufacturer of the chair or in any store that carries its products. An office chair cylinder repair kit is usually not very expensive.
If you are doing the replacement in your home, be careful because the lift mechanism will contain compressed air, oil and/or another fluid that will be under pressure. Attempting to over-tighten something, accidentally puncturing the cylinder or other damage to the mechanism can result in injury.
Pneumatic or Hydraulic Chair Repair
Normally, a desk chair can be easily disassembled using common tools or the specific tools that came with the chair at purchase. In order to access the mechanism, it’s usually necessary to remove either the seat of the chair, the wheel base or sometimes both.
Tip the chair onto its side and carefully remove whatever parts are indicated in the desk chair’s manual to access the cylinder mechanism inside the base of the chair. It should be easily removable and easy to replace a new hydraulic or pneumatic cylinder. Be careful, though, because these internal parts are often lubricated with oil that can stain clothing and carpet.
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