What are gas struts?

  • Gas struts contain highly pressurised nitrogen gas
  • Most strut failures relate to gradual loss of gas pressure
  • Struts can generally be re-gassed
  • Like any high pressure storage device there are certain risks, outlined below
The automotive industry was an early adopter of gas struts. They provide an elegant, compact, simple and cost effective solution to the problem of lifting and supporting components such as bonnets, boot lids and tailgates.

They are also commonly used in caravans and camper trailers and are now starting to appear in domestic applications such as kitchen cabinets.

Gas struts use stored pressure to assist in moving heavy objects. They contain highly pressurised nitrogen gas as well as a quantity of oil to lubricate the seals and slow (damp) the movement of the device.

Internal pressures are typically in the range of 1700 to 15200 kPa, (250 to 2200 psi) and are carefully calculated to provide the level of assistance required for the particular application.

In normal use gas struts are very durable however they do have a life span. Most strut failures relate to gradual loss of gas pressure which results in them being unable to support their design load, and the risk that the component being supported will gradually creep down or drop without warning. Loss of efficiency can typically start to occur after about five years of use, though some last considerably longer.

Struts can generally be re-gassed and there are a number of specialist operators providing this service. Check the Yellow Pages for one in your area. Alternatively, replacement struts are readily available, either as genuine or aftermarket parts.

Gas struts are generally very safe if handled appropriately. However like any high pressure storage device there are certain risks that need to be considered.  Deaths and significant injuries have resulted from inappropriate handling.
  • Gas struts should be protected against over-extension, side loading and excessive heat.
  • Do not weld or apply heat to struts or adjacent areas as they may explode.
  • Do not dispose of gas struts in fires due to the risk of explosion.
  • Maintain a safe distance from burning vehicles due to the risk posed by exploding struts.
  • Do not crush or puncture pressurised struts. Seek the manufacturers’ advice about appropriate methods of depressurising before disposal.
Where a strut has been subjected to forced over-extension, there is a risk of internal damage that could result in parts being ejected at high speed when the strut is removed from its mountings.

Warning: A gas strut damaged in this way may not be readily detectable and could appear to operate normally until it is removed.

For those ‘do-it-yourselfers’ intent on using a gas strut in a new application it’s important that they be installed in accordance with the manufacturer’s recommendations. This includes aspects such as design, operation, orientation, dimensional limits, load capacity and geometry. Strut manufacturers will often provide information about such matters.

More information

Should you require further assistance please contact our Motoring Advice Service or email us a question now.