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What Are Rotary Shaft Seals?

Rotary shaft seals, often referred to as oil seals or lip seals, play a crucial role in various industrial and mechanical applications.

These unassuming components are instrumental in preventing the leakage of fluids and the ingress of contaminants, ultimately ensuring the efficient and reliable operation of machinery and equipment.

In this comprehensive guide, we'll delve into the world of rotary shaft seals, exploring their functions, types, materials, and the key industries that rely on them.

What rotary shaft seals are used for ?

Rotary seals are mechanical gaskets designed to create a barrier between a rotating equipment or reciprocating shaft and its housing or bore.

Their primary function is to retain lubricants within the system and prevent the entry of dust, dirt, water, or other contaminants that could potentially damage the equipment, it can also protect from high pressure.

The fluid sealing edge will be less or more efficient depending of the fluid, the sealing lip will act the same.

By maintaining a tight seal, these seals extend the life of machinery, reduce maintenance costs, and enhance overall system efficiency in many industries.

To resume, packing seals permit to prevent any leakage or water ingress of any fluid.

What are the different types of rotary shaft seals?

Today, there are many different types of lip seals and rotating shafts seals. Indeed, these seal models are declined depending on the profile, the dimensions as well as the materials to answer in an optimal way to the various constraints and applications.

Profiles :

  • OAS/CC = Double lip with steel springOA = Single lip with steel spring

  • OA/CB = Single lip with steel spring

  • ASP = Double lip reinforced (up to 5 bar pressure)

  • BB = Single lip + single external reinforcement with steel spring

  • BC = Double lip + single outer armature with steel spring

  • DB = Single lip + double outer armature with steel spring

  • DC = Double lip + double outer armature with steel spring

  • BD = Single lip + single external steel reinforcement, without spring

  • CD = Single lip, without spring

  • CK = Double lip, double steel spring

Seal materials :

Here, you can find the differents seal material :

  • NBR: also known as NITRILE, this material is mainly used to be in contact with oils and hydrocarbons from -40 °C to +110 °C. This model is also compatible with water and chemicals.

  • FPM: it can also be in contact with oils and hydrocarbons. It is more suitable for high-temperature use, as it can withstand temperatures from -20°C to +200°C.

  • FPMSS: this material indicates that the seal is made of FPM but with a stainless steel spring and not steel.

  • EPDM: it is often used to be in contact with mineral brake fluid and water. In terms of temperature, it can withstand from -50°C to +150°C.

  • MVQ: this material is used for carburation from -80 °C to +175 °C.

How to choose a rotary shaft seal?

First of all, it is important to know that the references on the rotary shaft seals cannot be used effectively to identify them. This is because each manufacturer uses its own part number for these parts.

OAS-35X47X7-NBR :

  • OAS = shape of the rotary shaft seal

  • 35X47X7 = inner diameter X outer diameter X thickness

  • NBR = material used

If not specified, the sealing rings have no direction of rotation (no oil reflux grooves). You can therefore use them without worrying about the direction of rotation.

How to mount your lip seal?

Although it may vary depending on the mounting, the side with the spring is usually mounted on the liquid or viscous side (oil, grease, water, etc.).

There is a variant of the rotary shaft seal with a spring on each side, which is known as the "CK" type. It is recommended when the seal must be made between two liquids (oil and oil, water and oil, etc.)

Find your rotary shaft seal on 123Bearing.com

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