EPDM vs. NBR Seals: Which Material Is Better for Your Application?
In the field of industrial sealing, EPDM (ethylene propylene diene monomer) and NBR (nitrile rubber) are the two most commonly used materials, but their properties are significantly different, which is directly related to the service life and application scenarios of seals. This article will make an in-depth comparison from four aspects: material characteristics, applicable working conditions, advantages and disadvantages, and selection suggestions, to help you quickly lock in a sealing solution that is more suitable for your needs.
Comparison of material properties
EPDM seals
Weather resistance and aging resistance: EPDM has a stable molecular structure and is the most resistant to ozone, ultraviolet rays, and extreme weather, especially suitable for outdoor or long-term exposure to harsh environments.
Chemical resistance: Excellent resistance to polar solvents such as water, steam, ketones, alcohols, weak acids/alkalis, and brake fluids, but not to aliphatic hydrocarbons and aromatic hydrocarbon oils (e.g. mineral oil, gasoline).
Temperature range: The conventional use temperature is -50°C~150°C and the special formula can be extended to -55°C~180°C.
NBR seals
Oil resistance: NBR is the material of choice for oil seals and fuel systems due to its excellent resistance to petroleum-based oils (e.g., fuels, lubricants) and aliphatic hydrocarbons.
Mechanical properties: The wear resistance and pressure resistance are better than EPDM, and it is suitable for dynamic sealing scenarios with high friction and high pressure.
Temperature range: Conventional use temperature -30°C~100°C, low-temperature resistant model can be extended to -55°C.
| Characteristic |
EPDM |
NBR |
| Oil resistance | Poor (swelling easily) | Excellent (petroleum-based oil products) |
| Ozone/aging resistant | Excellent | Poor |
| High-temperature resistance | Excellent (up to 150°C) | Medium (up to 120°C) |
| Low-temperature resistance | Excellent (-55°C) | Medium (-30 °C conventional) |
| cost | Medium | Lower |
Applicable working conditions and industry applications
Prioritize EPDM scenarios
Water treatment systems: EPDM is highly resistant to water, steam, and water-soluble chemicals (e.g. chloramine disinfectant) and is widely used in pipe sealing, water pumps, and drinking water equipment.
Automotive cooling system: high-temperature coolant, brake fluid, and ozone environment, suitable for radiator sealing and air conditioning lines.
Chemical equipment: Occasions that require long-term exposure to ketones, alcohols, or weak acids/bases, such as reactor liners.
Prioritize NBR scenarios
Fuel and lubricating oil systems: Fuel pump seals, fuel tank gaskets, and other scenarios that require high oil resistance.
Hydraulic equipment: resistant to high-pressure oil impact, suitable for hydraulic cylinder seals.
Food processing machinery: NBR material that meets food grade standards can be used in equipment that comes into contact with animal and vegetable fats and fats.
Selection Guide: 5 Steps to Lock in the Best Material
Clarify the type of media
If the medium is water, steam, or polar solvents (such as alcohol, or ketones), EPDM is selected;
If the medium is petroleum-based oil or a non-polar solvent, choose NBR.
Assess the ambient temperature
EPDM is preferred in ultra-low temperature (<-30°C) or high temperature (>120°C) environments.
Consider dynamic/static sealing
Dynamic seals (e.g. rotating shafts) require higher wear resistance and better NBR.
Certifications and Compliance
Drinking water systems require NSF/ANSI 61 certifications, making it easier to meet EPDM standards.
Cost and life balance
If the budget is limited and the operating conditions are mild, NBR is more cost-effective; If long-term weathering resistance is required, EPDM can reduce the frequency of replacement.
Common Myths and Solutions
Myth 1: EPDM is resistant to all chemicals
→ Correction: EPDM is not resistant to mineral oil, and NBR or fluoroelastomer should be used for contact with oil.
Myth 2: NBR is suitable for high-temperature steam environments
→ Correction: NBR is prone to hardening and cracking when exposed to > 100°C environment for a long time, and it is recommended to use EPDM or fluoroelastomer instead.
Epilogue
Choosing the right EPDM or NBR seals not only increases equipment reliability but also significantly reduces maintenance costs. If your application involves complex media, such as mixed oil-water environments, consider a custom composite material solution. Contact us today for a free material selection consultation and sample test to match the best sealing solution for your equipment!
