Rubber Properties of Oil Seals: Types, Advantages & Specification

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Note: Above colors are based on TCS standard, for other special colors, please take PANTONE for reference.

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Oil Seal Material Design Guide

Lip Materials

Nitrile Buna-N 70 durometer compound is the standard material for our seals and is recommended for a majority of common applications. Nitrile lip seals work well within the temperature range of -65°F to 250°F and provide compatibility with water and most common mineral oil and greases.

Polyacrylate compounds are recommended for higher temperature applications, ranging from -30°F to 300°F. They also work well with mineral oils, EP additives and greases. However, they offer poor sealing in dry running conditions and cost more than Nitrile.

Silicone compounds offer the widest range of normal operating temperatures ranging from -90°F to 340°F. However, they do not perform well in dry running conditions, and should not be used with EP compounds and oxidized oils.

Viton® compounds are premium lip materials offering the widest temperature range and chemical resistance. Viton® will handle temperatures from -40°F to over 400°F (-40°C to over 240°C).

Viton® will resist most special lubricants and chemicals that can destroy Nitrile, Polyacrylates and Silicones. Viton® is extremely resistant to abrasion and provides superior wear performance. Viton® works in dry running applications, but only for intermittent periods.

Graphite is available as an additive to any compound. Normally graphite is added at a 3% factor to aid in lubricity.

Case and Spring Materials

The cases and springs for our seal products are produced from carbon steel. In applications where corrosion resistance is important, either case or spring or both can be produced from stainless steel. In addition, rubber coated seals can provide the best resistance to corrosive environments in the most economical design. HYPALON® coating is an O.D. sealant which is available on any metal case design by customer request.

Lip, Case and Spring Tables

The following tables identify the most common lip and case designs. Additional, more complex designs are available for special applications; however, the lip and case designs below represent those which will fill the needs of most seal requirements.

Lip Design

The following designations indicate the configuration of the sealing members:

V = Single Lip  U = Triple Lip  K = Double Lip  D = Double Lip, Double Spring Loaded  S = Single Lip, Spring Loaded  WP = Wiper Lip Design  OB = Oil Bath (Prefix) O = External Seal Type WS = Wiper w/Bronze Scraper

Case and Spring Design

The following designations indicate the case type or any special features of the basic case designs. The designations for lip designs, attachment configuration and case style are then put together to indicate the specific seal type desired.

A = Double Case  N = Short Flex High Pressure Design  B = Lip Attached to End of Case Only  P = Flanged Case  C = Fully Rubberized Casing  Q = All Rubber Split Seal Design  E = Metal Reinforced Sealing Lip  SP = Other Special Feature  F = Special Fully Encased Design  X = Special Fitting Condition Design  G = Ridged Rubber Coated O.D.  Y = Indented Back Case  H = Reverse Case Style  Z = Rubber Covered Chamber J = Special Flanged Indented Case NOTE: Basic single case design has no designation M = Fully Rubberized Inner Case

Oil Seal Lip Design Chart

The following Lip Seal designs are the most common, if your application calls for a design not listed below, please contact Monroe Seals.

Viton® is a registered trademark of DuPont® Dow Elastomers L.L.C

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Daemar manages the sourcing and delivery of millions of Essential Components to the manufacturing and MRO marketplace. I... Read more

With thousands of oil seals to choose from, how do you know which is the correct style, size and material for your application? Daemar can help.

The Oakville, Ont.-based company provides seals in a variety of material types, including Buna-N (Nitrile) rubber, Viton (fluorinated) rubber, EPDM (ethylene propylene diene monomer) rubber, silicone, PTFE (polytetrafluoroethylene) and polyacrylate. Each comes with its own advantages and, sometimes, disadvantages. 

• Nitrile rubber – Nitrile rubber is the most commonly used material for oil seals. It has a strong resistance to oils, salt solutions, hydraulic oils and gasoline. It can operate at temperatures between -40 and 120 degrees C. It’s important to note, however, that nitrile rubber has a poor chemical resistance.
• Polyacrylate rubber – This is an acrylic rubber with a better heat resistance than nitrile rubbers. It can operate at temperatures ranging from -20 and 150 degrees C. This material should not be used with water or temperatures below -20 degrees C. Polyacrylate is a good choice for high surface speed environments.
• Silicone rubber – Functioning in temperatures as low as -50 degrees C and as high as 180 degrees C, silicone rubber oil seals are unsurpassed in their tolerance to heat and cold. They have a high lubricant absorbency, which minimizes friction and wear, making it the ideal choice for crack shafts seals. Silicone, however, has a poor hydrolysis resistance. It is not the material of choice for oxidized or hypoid oils.
• Fluorinated rubber (Vitron) – This rubber has the best resistance to chemicals and a superior performance at high temperatures, but it is also the most expensive.

Not sure which material best suits your application? Daemar has a 30-year reputation for high-quality products and excellent service, and the experience to guide its customers to the appropriate choice.

“We offer a range oil seals in both metric and imperial measurements to fit your needs. Our rotary shaft oil seals will extend the life of your bearing systems while reducing maintenance costs,” the company says. “Aside from allowing your bearings to retain optimal lubrication, our rotary oil seals will keep contaminants out of your system.”

Contact Daemar to learn more. 

 

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