generic data on storage time and duration of operation of elastomers and rubber-metal components
the prescribed storage time of our products is in accordance to DIN 95360:
storage time |
|---|
| from initial delivery | max. 10 quarter years (storage prior to installation) |
| from initial installation | max. 20 quarter years (storage prior to installation) |
as maximum storage time, we adhere to the guidelines of ISO 2230:
| group classification | initial storage time | extended storage time (after checking the elements) |
|---|
| group A material (NR, SBR,BR,…) | 5 years | 2 years |
| group B material (NBR, CR, IIR,…) | 7 years | 3 years |
| group C material (EPDM, silicones,…) | 10 years | 5 years |
To be noted: a deviation from the storage temperature of 25° C results in altered storage times - a storage temperature of +10 ° C ( from 25° C ) reduces the storage time by 50%, a storage temperature of -10 ° C ( from 25° C ) extends the storage time by 50% |
the duration of operation - in accordance to DIN 95360 - is specified as below:
duration of operation |
|---|
| operating temperature [ °C ] | allowed duration of operation in years with up to 3000 operating hours 4 |
| -30 to 55 | 10 |
| -30 to 80 | 5 |
| 4 with excess of 3000 operating hours per year and/or the influence of aggressive media such as e.g. ozone, oil mist, salt water or salt-containing air, the possible duration of operation may reduce significantly |
In general, if applied within the allowed load range and owing to the natural ageing process of rubber, a recommended duration of operation of max. 6 years must be assumed. Latest after this period, an inspection and assessment of a representative number of components should be executed.
Rubber-metal components and form-based rubber parts are maintenance-free during the operational period.
Replacement is due, if:
- by means of setting and creeping towards the direction of pressure only 70% of the initial rubber thickness is achieved
- by means of the influence of weathering several clearly visible cracks per cm² rubber surface have formed
- the items have swelled significantly under exposure of non-permissible oil wetting
- a loss of the rubber-metal adhesion has occured ( e.g. due to corrosion of the metal components )
- mechanical damage can be observed, which can lead to a further destruction of the product due to the notch sensitivity of the caoutchouc
The above information is provided in all conscience and to the best of knowledge, however, the former recommendation can only serve as a theoretical guideline, and does not absolve the user from the neccessity of own assessments and test procedures. bwz® Schwingungstechnik GmbH expressedly excludes any and all liability for damages or disadvantages whatsoever, even in regard to third party protective rights.
