How to select the correct seal

Rubber represents a family of materials (elastomers) where the main characteristic is the high elasticity, ie: the ability to return to its original shape once removed from the source of the stress. For this reason it is considered the best material for objects such as seals.

PPE manufactures seals from 17 different types of rubber/elastomer, and offers over 300 different grades, so how do you choose?

Many factors have to be considered when selecting the optimal elastomer material for a particular sealing application. The most important parameters are temperature, chemical compatibility and physical properties.

Temperature 
What is the minimum and maximum temperature at which the seal must operate? Continuous or intermittent? The temperature at which a seal ceases to function is dependent on the elastomer used, the seal geometry and temperature of adjacent equipment. 

Chemical Compatibility
What chemicals will the seal have to withstand?
Will the contact be continuous or intermittent (how frequent)?
Elastomers experience physical or chemical change when in contact with process chemicals (liquid, powder or gas), cleaning agents or environmental effects (eg. UV light, Ozone).

Take a look at our interactive chemical compatibility guide which takes you through a list of over 1000 chemicals, and provides details of suitable PPE elastomer materials.

Mechanical Properties
What is the seal's function? Is it static or dynamic? 
What is the optimum hardness, tear strength, tensile strength, elongation, modulus, compression set and abrasion resistance required?

Standards and Approvals
Does the seal need to be compliant with a particular standard? 
For example, FDA, 3-A, USP Class VI, NORSOK, etc?

Need help selecting the right elastomer? Contact us for advice and material recommendations.