Rubber hoses storage conditions
Over a long period of storage, and particularly when they are subjected to certain factors described hereinafter, physical properties of hoses are modified in such a way as to lose their initial characteristics.
The correct storage conditions ensure maximum protection and reduce deterioration of polymers.
Duration of storage
- Up to 3 years : use without restrictions
- From 3 to 6 years : make visual inspection. take samples and carry out hydrostatic test at twice working pressure
- From 6 to 8 years : complete visual inspection. take sapmles and carry out destructive tests
- Over 8 years : do not use
All tecalemit rcmh hoses are marked with a date or number indicating date of production and date of placing into stock.
The ideal storage temperature is 15°C and the acceptable range is from 0°C to +35°C.
Hoses must not therefore be placed near a source of heat. In all cases, stored hoses should not be subjected to temperatures over +50°C or under -30°C.
Moreover, large fluctuations in temperature during storage lead to premature ageing of hoses.
cracking caused by ozone increases with temperature.
It is recommended to avoid relative humidity above 65%.
Direct light is one of the main sources of ageing.
In all cases, it is necessary to keep articles away from sunlight or strong artificial lighting.
Should the storage area have large bay windows, these should be covered with red, orange or white coating, or the items should be packed in an opaque wrapping.
Ozone is an ageing factor which must be taken into account.
It is therefore necessary that storage areas are exempt of ozone generating equipment such as mercury vapour lamps or spark-producing equipment such as alternative current electrical motors.
Also, the circulation of air around and inside the hoses should be limited, for example, by keeping the, original packing and plugging hose ends.
Hoses should also be kept away from workshop areas where they could be exposed to projections of oil, solvents, detergents or rodents.
Bend radius in storage
Ozone is a major factor of aging which creates cracking in the rubber.
When the hose is curved, the tension exerted on the outer cover has a tendency to enlarge them. consequently, the smaller the bend radius, the more likely it is that cracking will appear.
Method of storage
The principal to follow is to store hose in straight lengths, layed flat on supports, with should the hose be stored in reels, it is preferable to avoid stacking them in piles, as this could create a permanent deformation of the hose.
Hoses should not be suspended on hooks and in general any flexions or tractions should be avoided.