Precautions and use of gas springs

Reminder: Gas springs are devices containing nitrogen and oil under pressure. This pressure can reach 160 bars rod outside and 250 bars rod inside.
The gas springs we offer are adaptable parts that can replace the original parts in many cases. However, a different feeling can be noticed between the original one and the adaptable one.
Always replace the gas springs in pairs to ensure optimal operation and to prevent twisting due to uneven loading.

- Do not subject the gas spring to shock, vibration, electric or magnetic fields.
- Do not expose gas springs to temperatures exceeding 80°C.
- Keep the piston rod free of dirt, spatter, paint, adhesives, solvents, or corrosive materials.
- Do not force a cylinder whose rod is blocked (see paragraph Neutralization).
- Above 150 N, the cylinder is difficult to compress by hand.
- Do not damage the body of the gas spring (cuts, abrasion, blows) which could weaken the strength of the body or an internal component.
- Do not remove the gas spring from the application while the rod is engaged in the body without first neutralizing it (unless it is fully open, rod extended).
- Used gas springs must be neutralized before being recycled (see neutralization procedure on the following document "safety protocol").
- It is recommended not to expose the cylinders excessively to salt spray, except for stainless steel INOX products. The resistance (h) to salt spray is as follows:

     o Chrome = 150 h
     o Nitrided = 190 to 200 h
     o Stainless steel = more than 1000 h

For a maximum period of 3 months, the gas springs can be stored horizontally, in a room at room temperature.
For a maximum storage period of 6 months we recommend to store them vertically with rod down.
For a storage period longer than 6 months we recommend to operate the gas springs at least once before the 6th month in order to lubricate the rod and the internal equipment.

Do not transport gas springs in bulk. Make sure that the gas springs are not damaged by protective films or adhesive tapes. The rod must be free of any impurities.

Compression gas springs must be mounted with rod down and with a minimum inclination of 15°. If you have opted for traction gas springs, mount rod up.

Leave a clearance of 0.5 to 1mm between the end fittings of the gas spring and the mounting pin of the application, to allow the rotation of the end fitting on their pins during operation. 

The end fittings should be screwed in to the stop without over tightening. If the lateral stresses cannot be eliminated, we recommend to use ball joints.

Check that the gas spring is not subject to lateral forces.

In case of particle projection and/or in dusty environments, the rod must be protected. We offer wiper seals or protection tubes available on our website www.bertholdmarx.com

Yes, there are several parameters to take into account:

- Number of cycle/minute: 5 maximum. For higher cycling, please consult us. 
- Endurance level : 30.000 cycles on average. Loss of characteristics after endurance: 15% maximum (the level of endurance varies according to the stroke and the setting).
- Operating temperature: - 30° C to + 80° C.
     Reference temperature: +20°C Force variation due to temperature : 1% for 3°C

No, our gas springs do not require any particular maintenance. Please do not lubricate the rod with grease.

How to neutralize a gas spring?

To neutralize a gas spring, it is necessary to release the pressure contained in its body. 
This operation is necessary before scrapping it or before extracting it when the rod is blocked into the body, please proceed in the following way : ( wear safety glasses)

- Block the application if the gas spring is still in position. 
- Lightly clamp the gas spring in a vise if it has been removed from the application.
- Use a hand hacksaw for metal to gently saw the body of the gas spring in an area between 20mm and 30mm from the bottom of the tube (opposite side of the spring rod). 
- Cover the saw blade with a duster to prevent any projection of metal or oil. When you hear the gas coming out (hissing sound) stop the operation and wait for the gas to be completely evacuated from the body. 
- The degassing will be completed when the rod can be moved without constraint by hand. If this is not the case, make a second cut at the front of the tube (40mm from the front, or less for short strokes). 
- Dispose of the gas spring in a suitable container (the components are mainly metallic). The nitrogen used in gas springs is inert and environmentally safe. The internal oil should be emptied into an oil change container (we use mineral oil).

The end fitting on the body side of the gas spring is unscrewable and the thread is hollow.
In this hollow, the user can insert a rod which will come to be posed on the valve (a nail will be able to make the deal). Then, it is enough to strike with small damped blows on this stem. 
Attention : Always the valve at the top and rod down.

When adjusting 2 gas springs at the same time, we suggest counting the strokes to remove the same amount of gas from both sides.
Do not make more than 5 consecutive hits without first testing the GAS spring before (if necessary) repeating the procedure.

If you have emptied too much air, it is possible to refill the gas springs at the factory (Consult us via the contact form accessible on our site).