Coupling Insert Selection Guide

Our full range of flexible inserts permit custom design performance for a wide range of applications. All insert materials offer complete electrical insulation, as our factory design eliminates all metal-to-metal contact. Which Coupling Insert you select will vary based on the application, the fluid or chemical exposure, and temperature rating. The chart below shows compatibility of each insert with various fluids, with temperature ratings shown below.

Coupling Insert Performance Comparison

  • Material: Neoprene (Chloroprene Rubber)

  • Good general purpose material offering good resiliency and load capabilities.

  • Temp Range: -30F to +250F 

  • Recommended with: refrigerants (freon), high aniline point petroleum, silicate esters

  • Not Recommended for:

    phosphate esters, ketones






  • Material: Hytrel. 

    Most durable & versatile material, best all-around

  • Ideal for as engine & piston pump applications, ideal for high torque, high impact. 

  • Temp Range: -65F to +300F 

  • Recommended with: non-polar materials like hot or cold oils and hydraulic fluids; polar materials below 158F like acids, bases, amines. 

  • Not Recommended for: polar materials at elevated temperatures

  • Material: Urethane (polyurethane). Higher horsepower rating with similar characteristics to Neoprene.
  • Urethane tends to soften at higher temperatures and humid conditions. Not ideal for use with water or water-based fluids. 
  • Temp Range: -30F to +150F

  • Recommended with: Petroleum, alipnatic hydrocarbons

  • Not Recommended for: Hot Water, chlorinated hydrocarbons, phosphate esters

  • Material: Nitrile (Buna-N)

  • Excellent with petroleum products, excellent compression set and abrasion resistance

  • Temp Range: -60F to +250F 

  • Recommended with: Petroleum, Water, Diester, Water-Glycol

  • Not Recommended for:

    Halogenated Hydrocarbons, Phosphate Esters, Ketones, Acids, Brake Fluid

  • Material: Viton (Florocarbon)

  • Excellent Fluid Compatibility and high temperatures.

  • Temp Range: -20F to +350F 

  • Recommended with: petroleum, silicate ester, most phosphate esters, diesters

  • Not Recommended for: Oxygenated solvents, brake fluid, ketones

  • Material: EPDM (Ethylene Propylene Diene Monomer
  • Ideal for use in food-grade applications
  • Temp Range: -30F to +300F













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