Seals are usually used as spare parts and will last for a long time. O-rings may fail due to changes in their physical and chemical properties under the influence of distortions, oxygen, ozone, light, heat, moisture, oils, or solvents. In DIN7716, ISO2230, DIN9088 and other standards on the size of rubber seals, cleaning, maintenance of the basic provisions. Depending on the type of material, these standards provide specifications for storage conditions and recommended values for storage periods. To maintain the physical and chemical properties of elastomers, follow the following storage rules, which are intended to maintain an optimal storage condition:
◆ temperature: 5℃ to 25℃ is the ideal storage temperature. Avoid contact with heat source and sunlight. Seals removed from cryogenic storage should be placed in an environment of 20℃ for a period of time before use.
◆ humidity: the relative humidity of the warehouse should be less than 70%, avoid too wet or too dry, no condensation can occur.
◆ illumination: avoid sunlight and strong artificial light source containing ultraviolet. Uv - resistant packaging provides the best protection. It is recommended to paint the Windows of the warehouse with red or orange paint or stick sunscreen film.
◆ radiation: to avoid ionizing radiation damage to seals.
◆ oxygen and ozone: rubber materials should be avoided from exposure to circulating air. This can be done by wrapping, winding, storing in air-tight containers or by other suitable means. Ozone is harmful to many elastomers. Avoid mercury vapor lamps, high voltage electrical equipment, electric motors, spark or static electricity in storage.
◆ deformation: elastomer materials should be placed in a free state as far as possible to avoid tension, compression or other deformation. If the original packaging elastomer is in the state of no deformation, should use the original packaging. Contact with liquid or semi-solid materials: rubber seals shall not come into contact with solvents, grease, or other semi-solid materials (except in the manufacturer's original packaging).
Contact with metallic or nonmetallic materials: do not contact magnetic materials, cast iron, copper and alloys, or materials containing rubber that may be damaged. Do not use PVC material to package seals. Seals of different materials shall not be mixed together.
◆ cleaning: if necessary, use soap and water to clean seals. But the water is not allowed to contact the fiber reinforced seals, rubber metal bonding seals, AU products. Disinfectants, organic solvents and sharpened-edged tools are not allowed. The seal after cleaning should be dried at room temperature, not close to the heat source. Storage duration and monitoring
The storage life of elastomers is determined by the type of rubber materials. Under recommended storage conditions. The shelf life of these materials is as follows:
Polyurethane, thermoplastic material for 4 years
Dichloroprene, dichloroprene hydrogenated dichloroprene for 6 years
Ethylene propylene rubber for 8 years
Fluoro rubber, silicone rubber, fluoro silicone rubber 10 years
After the above mentioned time limit, it should be checked before use. After inspection, it may be able to be used for some time. Even if preserved in the above conditions, rubbers less than 1.5mm thick are easily oxidized and fail. Therefore, such products must be regularly inspected and tested, even in the above years.