Everything you need to know about Gas Struts

Dunn Watson Gas Struts on drop sown fridge slide

There are a number of different types of gas struts for sale in Australia, but what are they and how do you know which type you need? In this post we’ll take a look at these questions, so you won’t have any problems selecting the right struts for your needs.

What are gas struts?

Gas struts, also called gas springs, rams or dampers make lifting heavy or awkward objects easy. They are generally used to lift vehicle bonnets or boots, tailgates, horizontal opening windows and lids of heavy toolboxes. They are also used to open hatches and panels in boats and to adjust chairs and tables. They contain highly pressurised nitrogen gas with an oil based lubricant, and using a sliding piston and rod function, allow objects to be opened and closed smoothly and efficiently. Most people don’t pay any attention to the gas struts in their lives, it’s not until they become hard to use or stop working completely that they are noticed.

How do gas struts operate?

Gas struts have lots of different uses, and for each use they will be constructed slightly differently. Overall however, they all have a common functionality based on a piston and rod, similar to a bike pump or hand pump. Unlike these common hand pumps, the tube that the piston moves back and forth though is tightly sealed to contain the pressurised nitrogen gas. So when you open or close a window for example, the rod is either compressed into the sealed tube or extended, moving the compressed nitrogen gas within the tube from one side of the piston to the other. This creates a pressure differential and a force that allows the window to be opened and closed smoothly.

The flow of gas around the piston can be set by the manufacturer to apply a specific force that is required to open and close a particular object. For example, the force required to open and close a Ute’s tailgate will be different to the force required to open and close a small caravan window. Gas struts can exert a pressure of anything from a few kilos to half a tonne (from 50 to 5000 Newtons). Since the pressurised tubes are tightly sealed, they don’t need any maintenance or power source, and can last for years before they need to be replaced.

Types of gas struts

There are a number of different types of gas struts available in Australia, each manufactured for a different use. Below you will find a few of the most common types.

Standard gas struts: These operate as explained above where the pressure inside the sealed tube remains constant and is used to operate the gas strut.

Side valve gas struts: The main difference between standard and side valve gas struts is that these have a release valve on the side so that you can release the pressure for faster operation.

Locking gas struts: These can be locked in any position (open or closed) by turning a lever or a remote button.

Friction lock gas struts: You can lock these gas struts in any position using a large grip nut.

Lock open gas struts: These have a protective sleeve that automatically locks into position when the rod has reached full extension, locking it in the open position.

Protected gas struts: If the rod is likely to suffer damage due to the operating environment or the rod is particularly long, then you need a protection cover that extends its life and protects it from minor impacts, dirt and moisture.

Can gas struts be regassed?

Not all gas struts can be regassed, it depends on whether or not the seals that keep the compressed gas inside the tube have deteriorated or not. If the gas is low because these seals are no longer working properly, then regassing is not an option. In this case, it’s better to replace the gas strut.

Three common reasons people purchase gas struts 

Most people purchase Dunn & Watson gas struts because their existing struts no longer work properly. They might have bought a second hand Ute for example, and found that the struts for the bonnet and tailgate are pretty useless. On the other hand, you might have held onto your Ute for so long that the gas struts have simply lost their capacity to operate effectively over the years.

Another reason that Dunn and Watson have so many gas struts options is because people want to increase the force used to open and close a window, panel, hatch, etc. This often happens when the wrong struts were installed in the first place or simply because you want to make it super easy to open and close an object.

The last reason people purchase our gas struts is because they are fed up with struggling to open and close windows, panels, tailgates without gas struts. These make life so much easier that people give up after a while and decide to install a few gas struts so that they don’t have to keep struggling to open and close things.

How to select the right gas struts for your needs

When looking at gas struts for sale, most people opt for standard gas struts, but whichever type of gas strut you need, there are measurements that need to be taken so that you can find the correct replacement. The measurements you need include the following: strength (Newton force), extended length, stroke length, diameter and compressed range.

Strength: This is measured in Newtons and should be marked on your current gas struts. There is likely to be a label or an engraving that gives you this force.

Extended length: You need the length of the gas strut when it’s fully open or extended.

Stroke length: This is the part of the rod that goes in and out the sealed tube when the window or tailgate is open and closed. You measure the stroke length from the end fitting to the tube.

Diameter: You want both the diameter of the rod and the tube.

Compressed range: This is the length of the entire gas strut when it’s fully closed.

At Dunn & Watson, we have a large range of gas struts for sale, so if you need any help selecting which gas struts you need for your situation, just give us a call on 1300 210 549.