Chemical-resistant seals rarely face just one chemical. Over its life, a single pump or valve may see solvents, acids, caustics, and cleaning agents. Consequently, a seal that handles one stream can fail quickly in the next. This article explains how to choose seal materials by solvent family, from ketones and aromatics to strong bases and amines. It also covers when FFKM, encapsulated O-rings, or spring-energized PTFE seals are the right fit. For material selection in other industries, see our Complete Guide to Elastomer Seal Materials.
Chemical Resistant Seals
Chemical processing plants run pumps, valves, mechanical seals, pipe couplings, and reactors on aggressive media. Often, a single line carries several chemicals over its life. For that reason, chemical-resistant seals must cover the whole process, including cleaning steps. Marco’s chemical processing (CPI) guide details the options.
Elastomers Compatible with Aggressive Solvents
No single elastomer resists every solvent except FFKM. Therefore, start with the solvent family and narrow from there.
- Ketones (MEK, acetone, MIBK): EPDM works for many ketones. However, it fails in oils. Among fluoroelastomers, Viton® ETP (Marco V1020) and XLT or ULT types resist low-molecular-weight carbonyls, while standard FKM does not.
- Aromatic and chlorinated hydrocarbons: standard FKM performs well here. By contrast, EPDM and NBR swell badly.
- Strong bases, caustics, and amines: standard FKM types are not recommended. Instead, choose Viton® ETP (Marco V1020), Aflas®, or FFKM.
- Mixed or unknown streams: FFKM perfluoroelastomer is the safest choice. For example, Markez® Z1028 offers wide chemical compatibility to 610°F. Similarly, Z1352 offers an almost universal chemical compatibility and is recommended for use in chem sprayers, injectors, and reactors.
For harsh chemical service, spring-energized PTFE seals and FEP-encapsulated O-rings are proven alternatives to FFKM. Before finalizing, always confirm ratings in Marco’s chemical compatibility chart and its list of chemically compatible compounds and products.
Elastomer Materials by Industry and Application
Visit our Complete Guide to Elastomer Seal Materials to consult our quick reference tables for typical temperature ranges and elastomer seal materials by application. Read on to find application-specific recommendations for other industries.
- Elastomer Seal Materials for Medical Device & Pharmaceutical Processing
- Food and Beverage: O-Ring Materials Approved for Direct Food Contact
- Plasma-Resistant Seals and Elastomer Seal Materials for Semiconductor Fabs
- Elastomer Seal Materials for Oil & Gas: Subsea, Sour Gas, and Refinery Service
- Aerospace & Defense: MIL-SPEC O-Ring Materials for Fuel, Hydraulics, and Cold
- Elastomer Seal Materials for Automotive & Industrial Equipment
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Related Reading
Standard O-Ring Size Charts
O-Ring Groove Design Guides
Custom Sealing Solutions – From Prototype to Production
Engineered Sealing Solutions: Your Questions About Custom O-Rings, Compounds & Assemblies, Answered