All gas springs contain a small amount of oil to lubricate the main seal and rod. This oil also provides end of stroke damping.
In order to keep the rod seal lubricated, a small amount of oil is used in every gas spring. When used rod-down, the oil is kept in contact with the rod seal which improves the sealing properties and ensure the seal will never become dry.
For this reason, one of the basic recommendations when incorporating gas springs in your design is to make sure they are used at an angle of less than 60 degrees from the vertical.
The oil used in the gas spring is also useful to obtain a high damping effect on the last few millimetres of the stroke. If the gas spring was not used rod-down, the piston would not have to go through the oil at the end of the extension and no damping effect would occur.
When this is not possible and the gas spring has to be used either rod-up or near horizontal, an oil chamber or a fully damped gas spring should be specified. While these additional features add to the spring cost, they will enable your gas springs to reach their maximum operational life.
DO'S
- Do use standard gas springs rod down
- If springs are to be stored prior to use, the spring should be stored rod down to lubricate the seal
- Do try to use ball joints to help avoid side load forces. If eye (clevises) are used ensure a sloppy fit to allow lateral movement
- Do ensure that the end fittings are in line so that side load forces are not applied as a result of misalignment
- Do try to use shorter springs close to the hinge rather than long stroke springs away from the hinge
- Do provide physical stops to limit the spring’s extremes. i.e. ensure that undue force is not applied to over compress or over extend the spring
- Ensure the gas spring’s end fittings are fully screwed home
- Where ball joints are used ensure the ball stud is flush with the surface and tightened
DON'TS
- Do not scratch, dent, chip, bend or paint the rod
- Do not puncture or incinerate. IGS provides a disposal service at minimal cost
- Do not lubricate the gas spring
- Do not cycle more than 15 times per minute
- Under no circumstances attempt to re-gas a spring. This is an extremely hazardous operation
- Do not allow external objects to exert side load forces on the gas spring or on the end fittings
HEALTH & SAFETY
When gas springs are fitted to support loads where people are in danger should the load fall, a locking shroud should be employed. In addition, care must be exercised with regard to mounting position strength and end fitting suitability. It is critical to ensure that the end fittings are correctly installed both in the housing and to the spring to avoid additional loading on the fittings during use.