| General indoor sealing | -50°C to 150°C
-58°F to 302°F | Low to moderate static pressure | Excellent
Air, moisture, ozone, and UV exposure | Standard molded or extruded silicone rubber | 50–70 Shore A | Suitable for enclosure gaskets, covers, doors, and low-stress static joints. Confirm compression and dimensional tolerances. |
| High-temperature equipment | -60°C to 200°C
-76°F to 392°F | Low to moderate static pressure | Good
Dry heat, ozone, and weathering | High-temperature silicone compound | 50–80 Shore A | Silicone generally retains flexibility over a wide temperature range, but continuous exposure above 200°C should be validated with the seal manufacturer. |
| Outdoor and weather-exposed assemblies | -50°C to 150°C
-58°F to 302°F | Low to moderate static pressure | Excellent
UV, ozone, rain, and humidity | UV-stabilized silicone sponge or solid silicone | 20–70 Shore A | Choose sponge silicone for gap filling and low closing force; choose solid silicone where greater mechanical support or tear resistance is required. |
| Steam and hot-water service | 0°C to 180°C
32°F to 356°F | Low to moderate pressure | Good
Hot water and humid environments | Steam-rated silicone compound, subject to formulation | 60–80 Shore A | Not every silicone grade is suitable for pressurized steam. Check steam compatibility, pressure rating, compression set, and service duration. |
| Food-contact processing equipment | -50°C to 180°C
-58°F to 356°F | Low to moderate static pressure | Good
Water, dilute cleaners, and many food fluids | Platinum-cured or other compliant silicone, when required | 50–80 Shore A | Use only materials that meet the applicable food-contact regulations for the intended region. Validate cleaning chemicals, temperature, and repeated sterilization cycles. |
| Medical and laboratory equipment | -60°C to 200°C
-76°F to 392°F | Low-pressure static sealing or fluid transfer | Good
Water, dilute aqueous solutions, and many laboratory fluids | High-purity, post-cured silicone | 30–80 Shore A | Material selection must consider extractables, cleanability, sterilization method, and applicable biocompatibility or regulatory requirements. |
| Hydraulic or pneumatic static sealing | -50°C to 150°C
-58°F to 302°F | Moderate pressure; design-dependent | Limited
Compatibility depends strongly on the fluid | Reinforced or specially formulated silicone only when validated | 70–90 Shore A | Silicone is often less suitable for dynamic hydraulic sealing and high-pressure service than other elastomers. Evaluate extrusion gap, backup rings, hardness, and pressure cycling. |
| Contact with mineral oils and fuels | -40°C to 150°C
-40°F to 302°F | Low to moderate pressure | Limited
Many oils, fuels, and hydrocarbon solvents | Use silicone only after immersion and volume-change testing | 50–80 Shore A | Silicone can swell, soften, or lose strength in many hydrocarbon-based fluids. A fuel- or oil-compatible elastomer may be a better choice. |
| Strong acids, alkalis, or concentrated chemicals | Temperature depends on chemical concentration | Usually low to moderate static pressure | Limited
Chemical-specific validation required | Specialty silicone only where test data supports the application | 50–80 Shore A | Resistance varies with concentration, temperature, exposure time, and seal stress. Test the exact chemical mixture under actual operating conditions. |
| High-vacuum static sealing | -60°C to 200°C
-76°F to 392°F | Vacuum service; low permeation preferred | Good
Air and moisture environments | Low-outgassing silicone, subject to vacuum testing | 50–80 Shore A | Silicone is flexible and useful for many vacuum gaskets, but it has relatively high gas permeability. Consider leak rate, outgassing, surface finish, and compression stability. |
| Dynamic movement or sliding joints | -50°C to 150°C
-58°F to 302°F | Low pressure with repeated movement | Good
Weathering and ozone exposure | Low-friction silicone profile with suitable lubrication | 40–70 Shore A | Silicone has good flexibility but relatively low tear and abrasion resistance. Check friction, wear, lubrication, surface finish, and movement speed. |
