Oil Seals (Rotary Shaft Seals) – Paulstra

Why order your Paulstra oil seals from Solutions Élastomères?

Solutions Élastomères supplies Paulstra oil seals designed for rotary shaft sealing. Our range meets the needs of maintenance, replacement and equipment assembly for a wide variety of mechanical systems, for both professionals and private customers.

What is an oil seal?

An oil seal, also known as a rotary shaft seal or radial lip seal, helps prevent oil or grease leakage between a rotating shaft and its stationary housing.

It generally consists of a rigid casing, an elastomer sealing lip and, depending on the model, a spring that maintains contact with the shaft. This design provides dynamic sealing during rotation.

Seal performance depends on shaft speed, fluid, temperature, pressure and shaft surface condition. Correct dimensions alone are not sufficient if the material or lip profile is unsuitable for the application.

How do you choose the correct oil seal dimensions?

Three dimensions, expressed in millimetres, are used to identify an oil seal: the inside diameter (nominal shaft diameter), the outside diameter (nominal housing bore diameter) and the width of the seal.

The category filters help you search by size or part number. Before ordering, also check the material and lip profile: two seals with identical dimensions are not necessarily interchangeable.

Single-lip or double-lip oil seal: what's the difference?

The choice of lip profile depends on the fluid to be retained and the external environment. The Paulstra range includes IE and IEL configurations.

Single-lip oil seal – IE type

The main sealing lip is designed to retain lubricant, such as oil contained in a housing, engine or speed reducer.

Double-lip oil seal – IEL type

An additional dust-exclusion lip complements the main sealing lip. It helps protect the sealing area against certain types of dust and external contaminants.

Other lip profiles are available depending on the reference. When replacing a seal, retain the original seal type whenever possible or have its technical compatibility checked.

Which oil seal material should you choose?

The sealing lip material should be selected according to the fluid being sealed, temperature and operating conditions.

Please note: actual compatibility depends on the fluid, its concentration, temperature and operating conditions. If you are unsure about the material or spring, seek technical advice before ordering.

How do you select the right oil seal?

In addition to dimensions, several factors should be checked to ensure that a seal is suitable for your equipment:

• Material: compatibility with the oil, grease or fluid concerned.
• Lip profile: single lip, dust-exclusion lip or specific configuration.
• Shaft speed and temperature: operating limits specified for the model.
• Pressure and lubrication: permitted operating conditions.
• Shaft and housing: surface condition, alignment and dimensions.

For a crankshaft, gearbox or pump oil seal, start with the original manufacturer's part number whenever possible. Our team can help you find an equivalent reference based on your dimensions and operating conditions.

Where are oil seals used?

Oil seals are used in many types of equipment featuring rotating shafts, including engines, crankshafts, camshafts, transmissions, gearboxes, speed reducers, pumps and industrial machinery.

They help retain oil or grease inside mechanical systems and, depending on the lip profile, reduce the entry of dust. The seal must always be selected according to the specific operating requirements of the equipment.

Oil seal or O-ring: what's the difference?

An oil seal is primarily designed to provide sealing around a rotating shaft: its sealing lip remains in contact with the shaft during rotation.

An O-ring is mainly used for static sealing by compressing its elastomer cross-section in a groove. Certain dynamic applications are also possible with a suitable design.

To learn more about the differences, read our comparison of O-rings, SPI seals and lip seals.

Compare sealing solutions

How do you install and replace an oil seal?

Before installation, clean the housing and check the shaft surface condition. Scratches, localised wear or misalignment can compromise sealing performance, even with a new seal.

Follow the manufacturer's instructions regarding seal orientation and installation. Avoid deforming the casing or damaging the sealing lip when passing over sharp edges or grooves. Apply suitable lubrication whenever recommended.

If leakage continues after replacement, also check the shaft for wear and verify the operating conditions: the seal itself may not be the only cause of the problem.

Frequently asked questions about oil seals

There is no universal service life. It depends on the material, fluid, temperature, shaft speed, lubrication and installation.

Oil or grease leakage, a cracked sealing lip or reduced sealing performance may indicate wear. The shaft and housing should also be inspected.

Not necessarily: the material, lip profile and operating specifications must also be suitable for the application.

Replacement is generally recommended, as removal may damage the sealing lip or casing and compromise sealing performance when refitted.

We do not manufacture custom-made oil seals. However, our range of Paulstra oil seals includes many standard sizes. Our team can help you find a suitable reference for your requirements.

Need help choosing your oil seal?

Dimensions, material, lip profile, Paulstra part number or operating conditions: our technical team can help you identify the right seal for your application. Contact us to check a part number, stock availability or request a quotation.