What is a Gas Strut?
Principally, a gas strut (also known as a gas spring) is the same as a mechanical coil spring: it is a device for storing energy. Gas struts, however, store energy by compressing the gas contained inside, rather than straining material which makes up a coil spring.
How Does a Gas Strut Operate?
A gas spring is a closed system which requires no further gas to be introduced to the system for it to operate once charged with inert nitrogen gas and manufactured. The pressure on either side of the piston (reference point one) remains equal no matter where it is positioned; this is due to the small cross-sectional area of the rod (reference point two) where the gas is unable to exert any pressure.
As the rod is pushed into the tube, the gas contained in the spring is compressed increasing the pressure, with the compression of the gas creating the spring-like behaviour. The piston attached to the rod allows the flow of gas across the piston and provides the means of controlling the flow of gas as the rod is depressed and extended.