If you’ve assembled one office chair, you’ve no doubt seen one of these cylinders. The bottom goes into the wheelbase, the height inserts in ~ the seat, and also then you can magically raise or lower the chair to a comfortable elevation with just the flick the a lever, take care of or paddle.

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Most modern ergonomic office chairs come through these pneumatic cylinders. The “gas” is actually compressed air. And also most that the time, they work flawlessly. Especially if girlfriend bought her chair native a dependable company.

But if you want to know more about how your height adjustable chair in reality works, or what to perform if your gas cylinder fails and also needs to it is in replaced, friend may find this overview helpful.

In This Post present
What is a gas cylinder?
how does a pneumatic cylinder work?
parts of a Gas Cylinder
instead of a gas cylinder
Gas Cylinder sizes
What’s her stroke (aka travel)?
Weight capacity
remove the Old Cylinder
uncover a instead of

What is a gas cylinder?


A gas cylinder, also called a pneumatic cylinder or gas lift, is the unit that enables you to raise or reduced your office chair v the use of a lever below the side of the seat.

Unlike enlarge chair models that used a threaded spindle lift, where you had to rotate the chair counter-clockwise come raise and clockwise come lowe the chair, a gas lift chair uses a chamber v compressed waiting to readjust the elevation of a chair.

Also referred to as a spring, this chamber system makes it quick and also easy to change the chair relative to your desk height, therefore easily find a comfortable and ergonomic sit position.

How walk a pneumatic cylinder work?

As mentioned, a gas cylinder counts on compressed air to raise and also lower your seat.

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When the bar on her chair is engaged, the activates the cylinder. If you communicate the lever and while releasing your weight from the seat, the air in the cylinder compresses and also pushes the piston the end of the air chamber, thereby increasing your seat.

With the piston pushed out, the wait in the room is expanded, allowing the seat to be lowered as soon as you activate the lever and also push down with y our weight on the seat.

Parts that a Gas Cylinder


Standard pneumatic chair cylinders space composed of the complying with parts:

The was standing Pipe (aka external column): This is a 2” diameter key column the connects come the chairs’ five-star base. The bottom that the pillar in tapered. This is the end you insert right into the wheelbase when assembling one office chair. The size of the column and tapered section may vary from version to model, however the 2” diameter for the main column is typical with most cylinders.

Piston (aka inner column): The 1.1 customs diameter piston the connects to the seat base and also raises or lowers to adjust the chair height. The end of this unit is additionally tapered come fit right into the hole in the seat base unit (also recognized as the swivel unit). The top of the piston ~ above a new cylinder has a plastic cover. Girlfriend will remove that as soon as installing to reveal the button at the peak (aka the actuator).

Actuator: The switch at the optimal of the piston the gets pushed and also activates the cylinder come raise or reduced the chair.

Dust Cover: The telescoping plastic dust protector put over the main column.

Retainer Clip: The small clip at the bottom the the piston obelisk that keeps that from sliding out of the key column.

Retainer clip at bottom that the cylinder.

Replacing a gas cylinder

If you’re analysis an article about gas cylinders, there’s a an excellent chance you’re here since you actually must replace one.

Luckily, whether your chair came through a faulty cylinder, you need more “travel” and also height, or her faithful pneumatic chair is no longer “pneumatic” after every these years, it’s in reality pretty simple to change a gas cylinder.

The first step is to number out what size you need.

Gas Cylinder Sizes

As pointed out above, many cylinders come with standard diameter measurements for the was standing pipe and also piston.

So, prior to you begin looking at new cylinders, first confirm that your current cylinder has actually the traditional 2” diameter in ~ the base of the main column. Check out the image above for an illustration the this measurement.

**Do not include the plastic sheathe in this measurement.

Also check to see that you have a conventional 1.1” diameter piston.

Once you’ve shown that you’ll be able to use a standard diameter cylinder replacement, you will do it then require to number out exactly how much “travel” you want.

What’s her stroke (aka travel)?

If you’ve read many chair spec sheets (doesn’t everyone spend their time reading chair spec sheets?) you might’ve viewed the terms “stroke” and/or “travel” in referral to the chair cylinder.

This simply method that the cylinder will certainly raise or reduced the chair in ~ a certain variety of inches. Because that example, a 4 stroke chair cylinder is rather common, meaning the chair can be increased or lowered in ~ a variety of 4 inches.

The easiest means to determine the punch of your current chair/cylinder is to execute a fast measurement:

Raise her chair approximately it’s highest possible point. Currently measure the height from the floor to the seat.Lower your chair under to the lowest and also take the same measurement.The difference between the highest and also lowest point is your travel or stroke.

As mentioned, you’ll uncover that 4” is a pretty usual travel because that chairs, but this number can range from as low together 3” all the method up to 10”.

What travel range is ideal for you will count on her height, the elevation of the chair, and the height of her desk(s). For example, if friend need more chair height for a taller desk setup, you can discover a replacement cylinder through a much longer piston and therefore more travel than your present cylinder offers.

Weight Capacity

Another important factor to consider when it pertains to gas cylinders is the weight capacity.

Most chairs come with a proclaimed maximum pack capacity. For example, many large and high office chairs have the right to hold end 400 lbs, while traditional ergonomic task chairs could be closer come 250 lbs.

If weight volume of the chair structure is important, make sure your instead of cylinder is additionally up to the task.

For example, traditional cylinders can change with a capacity as much as 250 lbs. Yet “heavy duty” course 4 pneumatic tools can manage over 450 lbs (this would be crucial on a chair that qualifies because that ANSI/BIFMA huge occupant standards).

Bottom line: Make certain you obtain the right class cylinder that’s continual with your chair’s weight capacity limits.

Final note: additionally be certain to check if the cylinder is rotating or non-rotating to match the demands of your chair.

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Removing the Old Cylinder

Now comes the funny part. Just kidding, this deserve to actually be kind of a pain. But if you desire to revive your trusty old office chair v a fresh brand-new cylinder, you’ll must take the old one the end first.

You can shot this an approach (explained in the video) or keep analysis for simple basic measures that we’ve supplied in the past: