Choosing the correct oil seal application

Choosing and using the proper sealing devices within oil and gas applications can be vital when preventing dirt, dust, water, and other debris from potentially getting inside and contaminating products. 

Of course, all rubber materials and seals will provide a range of benefits; however, you will need to consider chemical compatibility, sufficient temperature ranges, pressure ranges, and more. 

At specialistsealingproducts.co.uk, we have a range of o rings and gaskets available to suit various applications across a multitude of sectors.  We work with clients to understand all needs and requirements, providing further information where required. 

Below, you will find a range of o ring materials outlining the properties and benefits so you can make an informed decision for your application.

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Oil seals applications

 

Oil seals can also be known as rotary shafts seals, shaft seals, lip seals, elastomeric seals, and more. 

Ultimately, oil seals are devices that help to exclude dust and dirt, etc., while at all times retaining the lubricant in the piece of equipment. 

Oil seal materials

 

Nitrile (also known as Buna N)

 

The most common and economical material within the sealing industry, Nitrile, is used in many oil applications, the automotive sector for aircraft fuel applications, military and marine applications, and more. 

The main benefits of Nitrile when opting for use as an oil seal includes: 

• It is petroleum-based oil and fuel resistant

   

• Resistant to silicone greases, water, and hydraulic fluid

   

• It offers a low compression set

   

• Has a high tensile strength

   

• Abrasion-resistant

   

• Can sustain temperature ranges from -40 degrees Fahrenheit to 257 degrees Fahrenheit.

   

Viton (Fluorocarbon)

 

A synthetic rubber used in gaskets, o rings, lip seals, and other moulded devices, Viton offers sealing properties for a range of oil-based applications.  Viton with high fluorine grades will also produce excellent resistance to swell, especially in oxygenated fuel and high-octane blends. 

In these instances, Viton can be the perfect sealing material for methanol/ethanol-blended gasoline. 

The benefits of Viton include: 

• Can sustain a temperature range from -13 degrees Fahrenheit to 446 degrees Fahrenheit

   

• It is resistant to high temperatures

   

• Resistant to various chemicals such as transmission fluid, petroleum oils, and gasoline

   

• It can be modified for applications with large chemical exposure and hard vacuums.

   

Silicone

 

Out of all of the elastomers, silicone offers you the widest range of working temperature ranges.  Renowned for its flexibility and low compression set capabilities, silicone is the optimal choice for o rings and other moulded seals. 

The benefits of silicone include: 

• It offers a temperature range from -85 degrees Fahrenheit to 400 degrees Fahrenheit

   

• It is ozone, weather, and sun resistant

   

• Phenyl based silicones can perform to -148 degrees Fahrenheit

   

• It is completely flexible (making it great for electrical insulation).

   

Fluorosilicone

 

An oil seal type that is resistant to oils, fuels, and solvents, fluorosilicone also offers temperature stability.  Primarily found in aerospace fuel applications and automotive fuel emission control, this o ring material is fast becoming popular in more and more oil-based applications across a wide spectrum of industries. 

Benefits include: 

• A temperature range from 75 degrees Fahrenheit to 400 degrees Fahrenheit

   

• It is resistant to high temperatures

   

• It has good compression set properties

   

• It can withstand exposure to ozone, air, and sun

   

• It is chlorinated and aromatic hydrocarbon resistant.

   

Atlas

 

Aflas is created from fluoroelastomers (FKM), providing the following benefits: 

• Temperature range from -10 degrees Celsius to 205 degrees Celsius

   

• Resistant to steam, petroleum oils, amine corrosion inhibitors, and hydrogen sulphide.

   

Carboxylate Nitrile

 

These oil seals are created from a low-temperature tolerant compound.  Benefits include: 

• Temperature range from -55 degrees Celsius to 135 degrees Celsius

   

• Resistant to abrasion, water, and petroleum oils

   

• Low temperature tolerant.

   

Propylene (fluorinated ethylene)

 

This tough, chemically inert polymer has a wide working scope as well as: 

• A temperature range of -55 degrees Celsius to 205 degrees Celsius

   

• Resistant to the majority of chemicals

   

• Ideal for static and slow intermittent dynamic applications.

   

Hydrogenated Nitrile/Highly saturated Nitrile

 

This is often the material of choice for the oil industry due to the extensive temperature range the material can sustain.  Benefits include: 

• Temperature range from -30 degrees Celsius to 170 degrees Celsius

   

• Petroleum oil and sour gas resistant

   

• Resistant to H25 and CO2.

   

Polyacrylate

 

Offering a much more superior temperature resistance, polyacrylate seals are perfect for applications such as high surface speed oil.  Benefits include: 

• Temperature range from -20 degrees Celsius to 150 degrees Celsius

   

• Resistant to petroleum oils and Freon.

   

Polyurethane

 

Typically used in hydraulic high-stress applications where compounds under high pressure are exposed to wear, the benefits of polyurethane seals include: 

• Temperature range between -15 degrees Celsius to 185 degrees Celsius

   

• Abrasion-resistant

   

• Offers a high degree of strength

   

• Petroleum oils and hydraulic oil resistance.

   

Perfluoroelastomer FFKM

 

An elastomer that has the broadest resistance to chemicals, elasticity, and a roust sealing strength, FFKM benefits also include: 

• Temperature range of -50 degrees Celsius to 327 degrees Celsius

   

• Resistant to the vast majority of chemicals.

   

To find the right o ring and gasket for your oil-based application, look no further than the o ring suppliers, Specialist Sealing Products.  On hand to provide you with the best information, call a member of our team today on 01535 274 776. 

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Description

Structure of oil seals and workings of each part

The following figure and table show the structure of oil seals and workings of each part, respectively.

Structure of oil seals and workings of each part

Main types, characteristics and related standards of oil seals

Materials used for oil seals

The following table shows main rubber materials, springs and metallic ring materials used for oil seals.

Main rubber material

Spring and metallic ring material

○： Usable　×： Not usable

Method of selecting oil seals

To make full use of the function of oil seals, selecting the most suitable shape and material for the use conditions is necessary. Generally, the following steps are followed:

• Select the shape.

• Select the lip material.

• Select the metallic material.

• Select the dimensions.

Since NOK offers a wide range of lineup that meets various requirements, please see our catalogs or contact the sales office nearest you.

Design of oil seal mounted portion

Since the shaft, housing shape, roughness, etc. influence the performance of oil seals, key points for general shaft and housing design are described below.

Key points for shaft and housing design

Material Chart for Oil Seals

Oil Seals are also known as a Rotary Shaft Seal, shaft seal, lip seal, elastomeric lip seal or any variation of these. It is a simple device for excluding dust, dirt, water or any other contaminant whilst retaining lubricant in rotary shaft equipment. Generally, it has been developed as a means of protecting the bearings of rotating shafts.

Below is the chart for Oil Seal Materials selection:

Temperature range: between -10°C and +205°C (intermittent/compound specific between -20°C and +250°C)

Applications: Aflas® are created from an exceptional Fluoroelastomer (FKM), which is resistant to steam, petroleum oils, amine corrosion inhibitors, and hydrogen sulphide.

Resistant to: Steam, Petroleum Oils, H2S

Temperature range: between -55°C and +135°C

Applications: Carboxylated Nitrile (XNBR) oil seals are created from a low-temperature tolerant compound, also has an excellent abrasion resistance.

Resistant to: Water, Petroleum Oils

Temperature range: between -20°C and +205°C or between -45°C and +230°C (intermittent/compound-specific)

Applications: FKM Fluorocarbon oil seals distinguish a great resistance to solvents and petroleum oils. They are, therefore, great for high-temperature installations and have present low compression set attributes. Additionally, they are adapted for use with large chemical exposure and hard vacuum applications.

Resistant to: Transmission Fluids, Gasoline, Petroleum Oils

Temperature range: between -55°C and +205°C (dependant on core material)

Applications: FEP oil seals are an excellent option for static and slow intermittent dynamic applications. FEP is interfered by a poor memory at low temperatures. FEP is, however, very tough, a chemically inert polymer that has a spectacular working scope.

Resistant to: Majority of chemicals

Temperature range: between -60°C and +180°C (intermittent/compound specific up to +200°C)

Applications: Fluorosilicone (FVMQ) oil seals incorporate a good low and high-temperature persistence of Silicone (VMQ) and Fluorocarbon’s resistance to solvents, oil, and fuel. It also presents great resistance to gasoline and petroleum oils.

Resistant to: Gasoline, Petroleum Oils

Temperature range: between -30°C and +170°C (intermittent/compound specific up to +190°C)

Applications: Oil seals produced from Hydrogenated Nitrile (HNBR) present superior sour gas and petroleum oils resistance. Due to an extensive temperature range of Highly Saturated Nitrile, it happens to be most preferable material in Oil Industries.

Resistant to: H2S, CO2, Petroleum Oils

Temperature range: Buna-N between -40°C and +135°C (intermittent up to +150°C); Low-Temp between -65°C and +120°C

Applications: Nitrile (NBR) is currently the most extensively used elastomer in the Fluid Seal Industry. Furthermore, Nitrile oil seals incorporate exquisite reluctance to hydraulic oils, water, silicone greases, petroleum-based oils and fluids, and alcohols. Nitrile presents great stability of working attributes such as high tensile strength, high abrasion resistance, and low compression set combined with low cost.

Resistant to: Water, Petroleum Oils & Fluids, Hydraulic Oils

Temperature range: between -20°C and +150°C

Applications: Polyacrylate oil seals have superior high-temperature resistance than that of Nitrile. Therefore, they are ideal for high surface speed oil applications.

Resistant to: Freon, Petroleum Oils

Temperature range: between -15°C and +85°C (intermittent/compound specific between -50°C and +100°C)

Applications: Polyurethane oil seals are used in high-stress hydraulic applications, in which highly pressured compounds are exposed to wear. Polyurethane, however,  presents a great high abrasion resistance qualities and high tensile strength.

Resistant to: Hydraulic Oils, Petroleum Oils

Temperature range: between -60°C and 250°C (special grades up to +300°C)

Applications: Silicone (VMQ) oil seals present a high lubricant absorbency. It minimizes wear and friction in certain applications.

Resistant to: Number of Acids, Petroleum Oils

Temperature range: between -50°C and +327°C (intermittent up to +350°C; compound specific)

Applications: Simriz® oil seals are created of an elastomer, which has the widest chemical resistance our of all elastomer materials. They incorporate all the elasticity and sealing strength of an elastomer and chemical resistance similar to that of FEP (Fluorinated Ethylene Propylene).

Resistant to: Majority of chemicals

The above information had been derived from numerous sources and the ratings are therefore intended as a guide only. Users must test under their own operating conditions to determine the suitability of any compound in a particular application and temperature.

M Barnwell Services is the UK’s largest independent stockist, manufacturer, and distributor of fluid sealing products and services. For more information about Barnwell O Rings click here, or to download a brochure click here.
For more information on our range of products click here.

E & OE. M Barnwell Services endeavours to make sure all the content is correct. Information has been gained from manufacturing partners.