Choose The Right Elastomer For Your Application

What Performance Characteristics Are Important In Your O-Ring Application?

In choosing the right type of O-ring material for operation your application, you want an elastomer that will withstand conditions common in your industry. With a wide range of rubber compounds available, you can select a material that will have the right physical characteristics to make it compatible to your use, with the gases and liquids it will interact with.

Properties Required By Elastomer

O-rings are intended to do a job of preventing leakage of gas or fluid from the point of the seal and must offer three basic characteristics:

  • Effectiveness Will the O-ring protect against the infusion of solids, liquids, or gases without its effectiveness been compromised?
  • Hardness How will the O-ring perform under pressure?
  • Toughness How resistant is the O-ring to physical forces such as pressure, elongation, and compression force

In addition to these two general properties, materials used for elastomers are often rated on a scale from poor to excellent, with certain properties being more important in certain usages than others. In deciding the best material for your O-ring applications, you need to consider many things. These often include:

  • Abrasion resistance How wear resistant is the compound when the surface is scraped around, as in dynamic applications?
  • Acid resistant Will the O-ring corrode and fail or facilitate corrosion on metal parts?
  • Chemical resistance Will the O-ring corrode in the presence of certain chemicals?
  • Cold resistance Especially in cryogenic applications, how will cold effect the performance of the O-ring?
  • Dynamic properties When the O-ring is subject to movement in a dynamic application, how does it hold up?
  • Electrical properties Will the O-rings adequately provide a seal, while shielding equipment from electromagnetic disturbances and protect it from electronic noise?
  • Flame resistance How will the O-ring seal respond in extremely high temperatures?
  • Heat resistance How will the volume, hardness, and compression set of the O-ring react to high temperatures?
  • Impermeability Will gas pass or diffuse through the elastomer, a special concern in vacuum service applications?
  • Oil resistance Will oil or additives in the product impact the effectiveness of the O-ring?
  • Ozone resistance Will the rubber crack or dry rot after exposure to ozone in the air?
  • Set resistance How well will the elastomer recover after it has been squeezed or subjected to high temperatures for a long time?
  • Tear resistance How likely is the elastomer to tear, nick, or cut during assembly, a warning of premature failure?
  • Tensile strength What is the result of pressure on the elastomer?
  • Water/steam resistance After water is converted to steam, how does the O-ring react to the heat and water swell, as it absorbs moisture?
  • Weather resistance When used outdoors or in harsh climates, how do the O-rings hold up?

Choosing The Right Parker Elastomer

When choosing the proper elastomer that will hold up and perform for your application, Parker offers charts in its online material and its InPHorm software interface that guides your material selection. If you need an elastomer with excellent acid resistance, you might choose a fluorocarbon, which is also heat and oil resistant, while having only fair tear resistance. If you need weather resistance, neoprene gives you that while offering fair set resistance. Nitrile is good to excellent in a dynamic situation, while offering resistance to ozone and extreme heat.

Whatever characteristics you need in your O-rings, Performance Seals offers the right Parker product for you. Click here for a catalog or contact us via our website.

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