Oil Seals 101 – Part 2

We offer quality sealing and cost-effective oil seal designs that help keep equipment running longer while reducing downtime. Through our comprehensive selection we provide oil seals with short lead times and with a variety of designs for use in many common and more challenging industry applications. When selecting an oil seal, it is important to know what sort of design is needed, and we have outlined a few of the more common elements below.

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Standard Sealing LIP Designs

oilseals-102-2Our oil seals have many different available lip designs, with some being simple and others complex, due to their special application. However, the most common industry lip standards are described below:

  • (single lip):  This design uses a garter spring and generally seals against internal media in lower pressure applications.  The single lip is not recommended for use in applications in which the environment contains dirt or contaminants.
  • (double lip): This design is also used with a garter spring and consists of a primary lip for sealing against internal media in lower pressure applications.  The secondary (also known as the auxiliary lip) provides additional protection from dust and dirt.
  • (dual or twin lip):  This design consists of garter springs and two identical primary lips that are usually used to separate two liquids. The space in between these two lips must be lubricated with grease or something similar.
  • (single lip):  This design has NO spring and is generally used for sealing a non-pressure medium, such as grease or protecting against dirt.
  • (double lip): This design has NO spring and is generally used for sealing a non-pressure medium, such as grease and is used to protect against dirt as well as internal and external media.

Standard Sealing CASE Designs

We offer oil seals in many various case designs from the most simple to the most challenging applications. Below are just a few of the most commonly used case designs for most sealing applications:

  • Type A: Outer metal case with a reinforced plate for structural rigidity. This design is mainly used on shafts when the diameters exceed 150mm, smaller shafts that need extra strength, or when used with special rubber compounds.
  • Type B: Outer metal case that is mainly used on shafts with diameters under 150mm with bore housing materials made of steel or cast iron. This design provides a firm and accurate seal in the housing; but may limit the static sealing on the outer diameter (O.D.).
  • Type C: Rubber covered metal case that can be used on any size shaft. The rubber helps prevent the metal from rust & corrosion, and prevents damage during assembly. This design is used in soft alloy, plastic housing materials, and for replacement in environments where there is minor damage to the housing surface.

Metal Case Finishes & Treatments

Oil seals with outer metal cases may include finishes or treatments that are applied to the outer edge to aid in rust protection, identification, and sealing of scratches or imperfections in the housing bore. Common finishes applied to the outside edge of metal O.D. oil seals include: Plain (a bonding agent that is usually a yellowish-green color), a Color Painted edge, and a grinded-polished edge.

Oil Seal Style Selection (Common Types)

Combining both the lip and case types explained above, it is easy to assemble the Global O-Ring and Seal (GOR) types as indicated in the following examples:

Type SC: Single lip w/spring, rubber covered O.D.
Type TC: Double lip w/spring, rubber covered O.D.
Type SB: Single lip with spring, metal O.D.
Type TB: Double lip with spring, metal O.D.
Type SA: Single lip w/spring, reinforced metal O.D.
Type TA: Double lip w/spring, reinforced metal O.D.

Factors in Oil Seal Selection

Our oil seals are available in both inch and metric sizes and are selected as follows:

  • Type: Combination of lip design and case type.
  • Shaft Diameter: The outside diameter of the shaft where the seal will operate (sometimes referred to as the I.D. of the oil seal)
  • Bore Diameter: The inside diameter of the bore housing where the seal will operate (sometimes referred to as the O.D. of the oil seal)
  • Width (or Depth): The depth of the bore (also known as the width or height of the seal). Note: When the width of the seal is not strictly specified, the depth of the bore is usually made big enough so a seal might be replaced by a wider one.
  • Sealing Lip material
  • Any special materials or considerations, such as stainless steel for the case and/or spring
  • Any special treatment or finish such as painted, polished edge, etc.

Oil Seal Designs From Global O-Ring and Seal

Global O-Ring and Seal offers a full line of oil seal designs in all industry standard sizes. If you are a distributor or purchaser who may have need for our oil seal products, contact us today to speak with one of our technical sales associates, request a no-obligation quote, or place an order online from our extensive inventory.

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Did you miss the first part in our series? Be sure to click here to read part one.

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