Prime Standard Oil Lubricated Seals

Prime Standard and Standard Secure Oil Lubricated Seals are compatible with a wide range of mineral oil and EALs.
AEGIR’s oil lubricated seals consist of three or four seal rings and a rotating shaft mounted liner. Dirt, particles and other debris cannot penetrate, seawater is kept out and oil is prevented from leaking into seawater.

AEGIR-Marine is a manufacturer and supplier of high-quality spare parts. AEGIR-Marine PRIME Parts® is their own make for stern tube seals, bearings, liners, O-rings and many more propulsion spares. The R&D department is responsible for all engineering and development.


Prime Standard Oil Lubricated Seals

Over the years AEGIR-Marine has developed many different types of seal assemblies. Careful engineering by the R&D department has led to spare parts as well as complete seal assemblies suitable for renowned makes like Wärtsilä, B+V Industries and Kemel. By applying modern technology and consistently choosing the best materials our seal assemblies meet the highest degree of quality and reliability

AEGIR-Marine Prime Standard.

The PRIME AFT seal consists of three sliding connections between PRIME seal rings and a revolving liner. 

AEGIR-Marine Prime Standard Secure.

In addition to the three AFT seals of the PRIME Standard, an extra seal is installed: Seal #3S. This seal points towards the stern tube and works as a backup for seal 3. When seal ring 3 is leaking, seal#3S will take over its job.

Options for both PRIME Seal types:

  1. On the AFT split type seal all housings and the liner are divisible. This means that there is no need for shaft withdrawal when seals and/or housing parts have to be replaced.
  2. When grooves appear on the surface of the liner, we offer the installation of an extra distance ring (spacer) to extend the liner’s lifetime. 
  3. To improve the lifetime of stern tube liners, we offer a tungsten coating. This coating can be applied on new and used liners and will be done within required tolerances. Since tungsten coating doesn’t wear over the years, this option is very cost efficient. 
Prime Standard and Standard Secure Key features 
  • Compatible with a wide range of EALs 
  • Protection ring prevents the ingress of foreign matter
  • Seawater is kept out and oil is prevented from leaking 
  • Fully split version available on request 
  • 3 or 4 lip configurations 
  • Class approved by most major classification societies 
  • Available immediately from stock

PRIME Seals and Biodegradable Lubricants:

With the introduction of the Vessel General Permit (VGP) by the USA, all vessels entering American waters must only use biodegradable oils for their propulsion system. Not every stern tube seal has the resistance needed to perform under the influence of the chemicals in these lubricants. PRIME Seals do. Right from the start high resistance Viton is chosen. So, there is no need to switch to a new, more expensive seal.

Anticipating, and in response to the VGP law introduction AEGIR-Marine has:
  • developed a PRIME Blue Seal that is water lubricated
  • developed a PRIMAIR Seal that guarantees to keep water and oil completely separated


AEGIR-Marine can supply spares suitable for existing systems or retrofit your existing system using Prime Standard or Prime Standard Secure.

They choose to have all PRIME Parts in stock, so you will never have to wait for weeks. Just call us and we will deliver them immediately. It’s as simple as that. 
In case of emergency we guarantee shipment within the hour.
PRIME Parts® distinguish themselves because of:

  • the high quality, equal or better (according to TNO & ERT-tests) than original spares
  • their fair price
  • their suitability for all major makes
  • the TüV-certificate, confirming that all our products have been produced in Europe
  • their class certification by all major class societies
  • the intensive quality controls
  • their careful packing in specially designed boxes.
Spare Prime Seal Rings:
  • are high quality components manufactured based on a unique Viton-formula
  • have a high resistance against biodegradable lubricants
  • have a perfect fit, guaranteed by our carefully designed moulds
  • are subjected to several manual checks before shipment
  • are always in stock
  • PRIME seal rings can -upon request- be produced in size 1250
Spare Prime Spacer Rings
  • Spacer rings (also called spacers) are installed between the stern tube and the AFT seal housing. The ring improves the durability of the liner and ensures a new, clean running surface for the seal rings.
  • Spacers can be installed without removing the propeller.
  • Available for seal sizes: 240 up to and including 1180. We can provide other sizes upon request.
  • Split (two halves), for installation without pulling the shaft.
  • Material: Mild steel.
  • Included: Longer bolts for installation and locking wire for securing the bolts and 2 flange sheet packings.
Spare Prime Liners
  • Our liners fit every make and type of lip-type shaft seal. 
    They are made from high-quality, wear-resistant chrome steel. Liners are available in sizes from 155 to 1180.
  • As one of the few suppliers in the world, AEGIR keeps castings suitable for Kamewa type liners in stock. Therefore, can deliver at short notice.
  • Available sizes standard: 155 up to and including 1180.
  • Available types: we can supply almost any make and type of liner.
  • Split liners can be supplied on request.
  • Kamewa liners: Sizes 300 up to and including 750 from stock.
  • We can produce other sizes on request.
  • Material: Special Chrome Steel, high resistance to corrosion and wear


I want to replace the seal rings on my Stern shaft without withdrawing the tail shaft, is this possible?

Yes, the seals can be split then hot bonded around the shaft with our specialist tooling and expert technicians.

I don’t have an AEGIR-Marine manufactured stern seal, can you still supply parts?

Yes, we are maker independent and can supply spares for most seal types, off the shelf.

I would like to change my Sterntube oil for something else, will AEGIR-Marine seals be compatible?

Almost certainly. We have an extensive list of approved oil both mineral and biodegradable. If it’s not on our list, then we can easily get it tested for you.

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