How to Choose the Right Seal for the Job; Radial Shaft Seals

By Dichtomatik on 29 June 16 Article

Cassette seal

How often do you encounter customers in search of a new replacement part, particularly radial shaft seals, or commonly referred to as an oil or lip seal? I’m going to venture and guess you or at least someone you work with has had to find a replacement seal for a customer.

It is not uncommon to think, “It’s a round seal. How hard can it be to a find the part number on the side of the seal, type it in the computer and hit the order button?”

However, what will you do when a customer needs a completely new style because the old style keeps failing? Even worse, what would you do if the seal is a vital part of a manufacturing line and their entire production line has halted because of this defective seal? Chances are that they will want to see results as quickly.

So whether you need to find a replacement part for an entire production line or a simple end user is looking for a few replacement parts, the list of questions and answers below will help you identify which type of seal is the right seal for the job.

radial shaft seals1.    Is the application rotating or reciprocating?
a.    If it is a rotating application, the appropriate part to use is a radial shaft seal.
b.    If it is a reciprocating application, the appropriate part to use a hydraulic (fluid power) seal

2.    Does the application involve continuous exposure to heavy contamination (dirt, mud, etc.)
a.    If yes, exploring options with our line of AP style cassette seals is recommended.
b.    If no, we recommend consulting our oil seal catalog to explore options. Or feel free to contact our engineering team here.

3.    Does the rotating shaft have a Rockwell hardness rating of at least 45 HRc?
a.    If yes, typically the shaft will not require a stainless steel protecting sleeve.
b.    If no, it is highly recommended to apply a stainless steel protecting sleeve in order to protect the shaft from wearing and grooving from the sealing lip.

4.    What type of material should be used depending on the rotation speed of the shaft in rotations-per-second (RPM’s)?
a.    0 to 1,000: Nitrile Butadiene Rubber (NBR) or Buna rubber
b.    1,000 to 2,000: Polyacrylate (ACM)
c.    2,000 or higher: Silicone and Fluoroelastomers

5.    What is the temperature range of the application (degrees Fahrenheit)?
a.    -40 to 225: NBR
b.    -40 to 302: Hydrogenated Nitrile Butadiene Rubber (HNBR)
c.    -13 to 302: Polyacrylate
d.    -60 to 390: Silicone
e.    -20 to 400: Fluorocarbon (FKM)

For more information or assistance in choosing the right shaft seal for the job, please call 1-800-328-2840