Oil Seal Buying Guide

Different Types of Oil Seals

Are you looking to keep your machinery free from any unwanted leakages but aren’t sure which rotary shaft seal is right for your needs? This guide will provide you with everything you need to know in order to select the right one for your application.

Oil seals, which are also known as rotary shaft seals, fluid seals or grease seals, play an important role in closing down the gaps between moving and stationary elements of mechanical equipment.

By preventing lubricants from escaping, they protect key components of machinery from being damaged by leaks of various fluids. Everything from car engines to assembly machines use these oil seals to remain free from any harmful interactions that can cause serious and expensive damage to any of their critical parts.

There are a wide range of oil seals to select from for any number of uses, so this guide will break down the most common seals to help you choose the right one for whatever piece of machinery you are working on.

What are rotary shaft seals?

Rotary shaft or oil seals are placed between moving and stationary pieces of machinery to ensure that contaminants, moisture, corrosive materials and abrasives do not damage the various components. They can also prevent unwanted mixing of fluids, including water and oil combining within a machine.

How are Oil Seals made?

First, an elastomer, most often nitrile, is vulcanised to a metal ring. This creates a stiffening effect that includes a specialised metal tension spring directly behind the sealing lip, keeping the oil seal firmly in place against the moving part.

Oil Seal Materials

There are many different materials used to manufacture oil seals.

Leather Oil Seals - Leather Seals, also known as Type L Oil Seals, are most common in components that are subject to dirt and poor lubrication. Since they come pre-lubricated and are able to absorb fluids, leather oil seals are able to provide sealing properties in conditions that synthetic rubber is unable to.

Synthetic Rubber Oil Seals - Styrene Butadiene Rubber oil seals, or just SBR oil seals, offer strong resistance to abrasions and lesions, making them an ideal seal for fast-moving machinery. With the ability to withstand extreme temperatures with its heat-aging qualities, they can be used in outdoor components. They are also seen as more cost-effective oil seals than natural rubber.

Nitrile Oil Seals - Nitrile oil seals, which is the commonly used term for acrylonitrile-butadiene rubber seals, is a very good general-purpose option due to the flexibility of use across a variety of components. The resistance is strong against fats, hot water, gasoline, mineral oils, grease and animal oils, making them the most often-used oil seals. They do not have a wide temperature range, making them a poor choice for machinery that can see extreme changes in temperature.

Viton Oil Seals - A synthetic rubber and fluoropolymer elastomer, Viton is used to make oil seals that provide resistance in both high temperature, up to 250°C and low compression set components. They also offer a high resistance to chemicals and abrasions, so they can be used in elements that regularly interact with petroleum and solvents.

Polyacrylate Oil Seals - Mostly selected for automotive and transmission uses, polyacrylate seals are able to withstand fuel, oil, ozone, sunlight and weather when used. With cars exposed to all these different fluids and elements, they are the perfect choice. However, they should not be used in low temperatures, as their flexibility weakens when cold.

Silicone Oil Seals - Designed to absorb lubricants in order to lessen wear and friction, silicone rotary shafts also offer high thermal resistance and a large temperature range. But, they do not handle abrasions well or interact with oxidized oils.

PTFE Oil Seals - A relatively new and exciting oil seal, the use of polytetrafluoroethylene means that they can withstand dry or unlubricated operations. With a massive thermal range of  -130ºC to +200ºC and a strong resistance to chemicals, they are considered to be the future of rotary shaft seals.

How to Choose the Right Oil Seal

There are several key factors to consider when you are selecting the oil seals for your next project to ensure that you protect your machinery from immediate and long-term damage.

Pressure - Many oil seals can only withstand low-pressure applications, so understanding the compression set of your components is key.

Temperature - Just like pressure, the temperature that your oil seal will be operating in must be known so that you can choose one that can withstand the heat or cold. PTFE have the widest range of temperature, making them useful for machines who can see usage in extreme weather or elements.

Shaft Speed - Considering the speed that the shaft will be moving, the runout, the housing bore and the type of oil being sealed is vital to making sure you select an oil seal that will not suffer from abrasions or spiralling.

Fluid Types - Various oil seals are able to withstand interactions with oils, fuels, grease, water and more. Knowing what type of fluid the rotary shaft seal will be in constant contact with will ensure the longevity of the seal and surrounding components.

Lubricant Amount - Seals will always perform best when lubricated, however in some machines there are more likely to be dry spells. For these cases, selecting a leather or PTFE seal will be beneficial, as both can operate with less lubrication than others.

If you require any assistance in discovering the factors that lead to the right oil seal choices, the Simply Seals Team is happy to assist you!

Find the right Oil Seal for your needs with Simply Seals!

With dozens of specifically-designed oil seals made from a variety of materials, it can be very difficult to understand the best choice for their machinery.

That is why the Totally Seals team is always available to assist you with choosing the correct style, material, and size of oil seal for everything from commercial machinery to hobby car building.

Contact us today to make sure that you select the proper rotary shaft seal that will protect your components and lead to a long, healthy life for all of your machines!

What is Oil seal:

Oil seals play a crucial role in preventing the leakage of lubricants or fluids in a wide range of applications. From automotive engines and transmissions to industrial machinery and equipment, oil seals ensure proper functioning and avoid damage caused by leaks. These essential components are designed to tightly seal the gaps between moving parts, thus keeping contaminants out and lubricants in.

An oil seal, also known as a rotary shaft seal, consists of a flexible, circular lip made from materials such as rubber or metal. The lip is pressed against the shaft or housing in which it is installed to create a seal. The lip's contact with the rotating or stationary parts prevents the escape of fluids, such as oil or grease, while allowing the shaft to rotate smoothly.

One key aspect of oil seals is their ability to withstand high temperatures and pressure conditions. They are made from materials that can handle the demands of various applications, ensuring optimal performance and longevity. These materials often include elastomers such as nitrile rubber (NBR), fluoroelastomers (FPM), or silicone rubber (VMQ).

Oil Seal Product Description:

Introducing our high-quality oil seals engineered to provide exceptional performance and reliability in a variety of industrial and automotive applications. Our oil seals are meticulously designed with precision and constructed with durable materials to effectively seal and protect against the ingress of oil, grease, and other contaminants.

Function:

Oil seals, also known as rotary shaft seals or lip seals, function as essential components in mechanical systems. They are primarily used to prevent the leakage of lubricants, such as oil or grease, and to retain fluids within a system. By creating a barrier between the stationary and rotating components of machinery, oil seals effectively minimize friction, extend the longevity of equipment, and ensure its optimal function. Moreover, they provide protection against external contaminants, such as dirt, dust, moisture, and corrosive fluids, which could potentially lead to damage and wear.

Features:

1. Superior Sealing Performance: Our oil seals are engineered with precision to deliver exceptional sealing performance, ensuring that lubricants stay within the system and contaminants are effectively kept out. This not only helps to maintain the integrity of the equipment but also reduces the risk of downtime, maintenance, and associated costs.

2. High-Quality Materials: We utilize only the finest quality materials in the construction of our oil seals, providing excellent durability and resistance to wear, temperature variations, and chemical exposures. Our seals are manufactured from premium elastomers, such as nitrile rubber, fluoroelastomer (Viton®), silicone, PTFE, or a combination of materials, depending on the specific requirements of the application.

3. Optimal Design: Our oil seals are intricately designed to meet the precise needs of different industries and applications. With a variety of configurations, sizes, and lip profiles available, we ensure an optimal fit and sealing solution for your specific machinery. Whether you require a single lip, double lip, or specialized designs such as cassette seals or mechanical face seals, we have you covered.

4. Easy Installation: Our oil seals are designed for easy installation, reducing the time and effort required to replace or fit seals within existing systems. They come with a flexible lip that can be easily pushed onto or around the shaft, providing a secure and reliable seal.

5. Wide Range of Applications: Our oil seals are suitable for numerous applications, including automotive engines, power transmission systems, hydraulic and pneumatic cylinders, gearboxes, pumps, electric motors, agricultural equipment, and more. From small assemblies to heavy-duty machinery, our seals effectively address various sealing requirements across industries.

6. Custom Solutions: We understand that every application comes with unique demands. Therefore, we offer custom-engineered oil seals tailored to your specific requirements. Our highly skilled engineering team can work closely with you to develop a solution that perfectly matches your application's needs, optimizing efficiency and durability.

How do you choose an oil seal?

1. Understanding the Basics of Oil Seals: Oil seals consist of an elastomeric lip bonded to a metal housing, usually made of steel or stainless steel. The lip contacts the rotating shaft, forming a dynamic seal that prevents fluid or oil from leaking. The metal housing ensures stability and provides a mechanical barrier against external forces. These seals are available in various designs, such as radial lip seals, axial seals, and rotary shaft seals, each tailored for specific applications.

2. Identifying Key Factors for Selection: To choose the ideal oil seal, several factors should be considered:

a) Shaft Diameter and System Pressure: Match the inner diameter of the oil seal to the shaft diameter for a secure fit. System pressure is another critical factor, as higher pressures may require seals with additional reinforcement or alternative materials.

b) Operating Conditions: Consider the environment where the oil seal will be used. Extreme temperatures, chemicals, fluids, or abrasive conditions necessitate the selection of specialized materials offering resistance to these factors.

c) Speed and RPM: High-speed applications require oil seals with lower friction to minimize heat generation and ensure smooth rotation. Understanding the required operating RPM of the shaft will help determine the appropriate lip design and material.

d) Seal Performance: Evaluate the expected lifespan and seal efficiency. Look for seals with high wear-resistant properties to enhance their durability and ensure long-term reliability.

e) Seal Type: Different applications require specific seal types. Radial lip seals are commonly used for rotating shafts, axial seals are suitable for linear motion applications, and rotary shaft seals are versatile options for various applications.

3. Choosing the Right Material: The material selection plays a crucial role in the performance and longevity of oil seals. Commonly used materials include:

a) Nitrile (NBR): Ideal for general-purpose applications, nitrile provides excellent resistance to oil, water, and some chemicals. It has good temperature resistance but may not be suitable for extreme conditions.

b) Fluorocarbon (FKM / Viton®): These materials offer superior resistance to high temperatures, chemicals, and fuels. Fluorocarbon seals excel in harsh environments and are often chosen for applications involving extreme temperature fluctuations.

c) Silicone (VMQ): Silicones are resistant to temperature extremes and have good low-temperature flexibility, making them suitable for food-grade applications and environments with high heat or low-temperature requirements.

d) Polyacrylate (ACM): ACM seals are known for their resistance to petroleum-based oils and lubricants. They perform well in applications with moderate temperature ranges.

4. Consulting Experts and Industry Standards: When in doubt, consult industry experts or manufacturers who specialize in oil seals. They possess in-depth knowledge and can guide you in choosing the most suitable oil seal for your specific requirements. Additionally, consider ISO and ASTM standards that outline quality criteria, physical properties, and performance benchmarks for oil seals.

Choosing the right oil seal is critical to ensuring smooth operations, minimizing leaks, and maximizing the lifespan of equipment or machinery. By considering factors such as shaft diameter, operating conditions, speed, seal type, and material, you can confidently select a high-quality oil seal tailored to your needs. Partnering with reputable suppliers and adhering to industry standards will further guarantee optimal performance and reliable sealing solutions.

2.  PRESSURE: Oil Seals cannot endure a lot of pressure. You need to understand your machinery’s pressure capabilities and ensure you use the correct seal to withstand its pressure levels.

3.  TEMPERATURE: Similar to the pressure level, you need to know what temperature your machinery can operate at. You need to choose a seal that can withstand the heat or cold. PTFE have the widest rang of temperature, making them a safe option when you are uncertain of the range.

4.  SHAFT SPEED: As different shafts move at different speeds you need to consider the runout, the housing bore, and oil type being sealed. Ensure you select a seal that will not suffer from abrasions or spiralling.

5.  TYPES OF FLUID: Numerous oil seals can interact with oils, fuels, grease, water and more. However, know exactly what type of fluid the rotary shaft seal will be in contact with will ensure the longevity of the seal and the machinery.

6.  AMOUNT OF LUBRICANT: Seals perform better when lubricated but some machines will go through some dry spells. When this occurs using a leather or PTFE seal will be more beneficial as those type of seals can operate with less lubrication.