Office chair hydraulic cylinders can be regassed or replaced.
Regassing the cylinder is a difficult and dangerous process while replacing it is usually easier and has little risk.
The hydraulic cylinder powers a major function of most office chairs, and understanding your options for regassing or replacing can help you get the most out of your chair.
Keep reading to explore these options and learn when and why you should replace the hydraulic cylinder.
What is an Office Chair Hydraulic Cylinder?
The hydraulic gas cylinder on an office chair is a pneumatic feature that allows you to adjust the height of the chair.
This gas cylinder sits between the wheelbase and the seat and uses a lever, handle, or paddle to activate the mechanism.
The air chamber of the gas cylinder connects to a plunger or piston that, when activated, moves air in or out.
While activated, the chamber alone raises the height of the chair, applying pressure at the same time will decrease the height of the chair.
Parts of an Office Chair Gas Cylinder:
Standard office chair gas cylinders have two parts.
The top part of the cylinder is the gas spring, and it usually has a diameter of 1.1 inches.
This holds materials necessary for adjusting the height of the cylinder, such as pressurized nitrogen gas and oil to lubricate the adjustments.
The gas spring features an actuator that lowers or raises the chair when pressed by the paddle or lever.
This top, tapered end of the gas cylinder is what attaches to the underside of the office chair.
The bottom is the piston that moves in and out of the cylinder to raise and lower the chair.
The column of an office chair gas cylinder attaches to the chair’s wheelbase, usually extending a bit past the bottom of this base.
Most columns measure about 2 inches in diameter.
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Can an Office Chair Hydraulic Cylinder be Regassed?
While regassing an office chair gas cylinder is possible, it’s not recommended.
The work to regas the cylinder is often too difficult and dangerous to merit the effort, and it’s safer and easier to replace the entire cylinder.
Another issue with regassing is that it usually does not return the chair to its previous condition.
Regassing also indicates the potential for more serious problems with the chair, such as a leak, and replacing the gas does not address that problem.
If you opt to replace or refill the gas in the chair’s pneumatic cylinder you should contact a professional to do the work.
They will have the tools and experience necessary to tackle the task safely and efficiently.
Replacing an Office Chair Hydraulic Cylinder
To replace an office chair gas cylinder:
- Make sure you choose the right replacement product
- Take the time to remove the old gas cylinder
- Pop the new gas cylinder in place
The process does not require intricate assembly, but you should prepare for a bit of muscle work when removing and securing the part.
You should need nothing aside from the new gas cylinder, a rubber mallet, and possibly a board of wood (to distribute force).
Identifying an Office Chair Gas Cylinder Type:
While most gas cylinders use the same diameter for the gas spring and column, the stroke is what differentiates the different types.
This is the difference in measurement from the lowest setting to the highest setting.
For example, a 6-inch stroke gas cylinder will travel 6 inches in height from its lowest setting to the highest setting.
You can measure the stroke of your office chair’s gas cylinder before disassembly to ensure the purchase of the correct parts.
Lower the chair completely and measure the height of the chair at the arm or the top of the chair’s back.
Next, raise the chair to its highest position and measure the height of the same component. The difference is the stroke.
Pay attention to this number; you don’t want to end up with a gas cylinder with a stroke that is too tall or too short for your needs. It should still fit, but the range of the chair changes.
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Removing the Old Gas Cylinder:
Start by completely compressing the gas cylinder (if possible, turning the chair over, and setting it on a stable surface.
You may need to get creative if the arms of your chair are in the way, or you can remove them to limit your brainstorming efforts.
This makes sure you don’t have to worry about holding the chair up as you remove the old gas cylinder.
Notice that the bottom of the gas cylinder extends past the wheelbase it locks into.
To separate these parts put a block of wood on the bottom of the column and tap the cylinder out of the wheelbase. You can apply upward pressure to the legs to help pull the two apart.
Once you’ve done this, repeat the process on the top of the gas cylinder. Depending on your model, you may need to remove anything that locks the cylinder into the seat of the chair, but it’s usually just wedged in.
Installing a new Gas Cylinder:
Installing the new gas cylinder is much easier than removing the old one.
Insert the tapered end in the appropriate hole in the seat of your chair, then use gentle pressure to ensure it wedges in securely. Repeat this process to reattach the wheelbase to the cylinder.
Before you drop into the chair, assuming the hydraulic cylinder is properly installed, make sure it works properly.
Tentatively press your knee into the seat to make sure it holds its height. Adjust it up and down, then you can enjoy the renewed function of your chair.
When to Replace an Office Chair Hydraulic Cylinder
You should usually replace the hydraulic cylinder of an office chair whenever you start to notice issues regarding chair height.
This happens regardless of how much you adjust the height of your office chair, and it can wear out faster if you don’t do this often.
Most chairs offer warning signs before the hydraulic cylinder completely loses function. Try to replace it as early as possible to avoid major problems.
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1. When the Gas Cylinder is Empty:
An empty gas cylinder is likely to lower quickly, but it will struggle to gain height. This happens over time as the seal on the gas cylinder wears out and starts to leak.
Even minute leaks will eventually lead to an empty gas cylinder. Even if you replace the gas in the cylinder, you’ll suffer the same fate down the line unless you also replace the seals.
2. When the Gas Cylinder is Rusty:
A rusty gas cylinder poses a major threat to your workplace. Rust indicates that the protective layer of the gas cylinder is thinning, and the metal is much more sensitive to external conditions.
This increases the chances of the hydraulic cylinder exploding, which happens more often than you might think it's one of the most common workplace accidents.
Replacing the cylinder is your only option with rust.
3. When You Notice a Leak:
If you notice a leak at all, even without an empty or rusty cylinder, you should replace it as soon as possible.
The hydraulic cylinder will empty over time, and the leaking of gas opens the door for the possibility of combustion or explosion.
It’s much easier and safer to replace the hydraulic cylinder than it is to regas it, and you no longer have to worry about an unfortunate accident occurring.