Prime Blue Water Lubricated Seals

The environmentally friendly stern tube sealing solution, AEGIR’s Prime Blue is a water lubricated seal that offers a reliable and durable alternative to oil lubricated solutions. Supplied partially split as standard, it can be easily maintained and changed whilst the vessel remains afloat.

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


Prime Blue Water Lubricated Seals

Over the years AEGIR-Marine has developed many different types of seal assemblies. Careful engineering by our 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.

The water lubricated PRIME Blue 

AEGIR’s PRIME Blue assembly is a reliable, durable seal system that is proven to be pollution free. It offers many benefits for vessels with water lubricated bearings. This type of seal is the easiest seal on the market for installation and operation. Maintenance, including changing the seal, can be completed by your own engineers while the vessel is in the water. Seals come standard in a partial split version but are also available as fully split on request. 

A straightforward design.

The design of the PRIME Blue type seal is very straightforward. It consists of a rubber lip seal rotating with the shaft. The lip seal rotates against a stationary mating ring made of chrome steel. The seal casing is made of cast bronze. An inflatable seal for emergency and maintenance purposes is installed in the housing. Seal assemblies are supplied with one spare seal, which is installed around the shaft ready for installation. This can be installed by your own engineers. 

Competitively priced and certified 

Spare parts are price competitive compared to other water-lubricated seals. All PRIME Blue spares are available on short notice. Class approval by most major classification societies is available. 

NOTE Prime blue seals can be serviced without docking. For retrofit purposes, the PRIME Blue can be supplied with adaptor flanges or in non-standard versions.

Prime Blue Key features:
  • A complete water lubricated seal assembly 
  • Fully split version available on request 
  • Can be serviced without docking 
  • For retrofit purposes, can be supplied with adaptor flanges or in non-standard versions 
  • Class approved by most major classification societies 
  • Spares available immediately from stock


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

We 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 Blue Seal Rings:
  • are high quality components manufactured based on a unique Viton-formula
  • have a perfect fit, guaranteed by our carefully designed moulds
  • are subjected to several manual checks before shipment
  • are always in stock


My water lubricated prime blue needs service, but we don’t have the time or opportunity to dry dock.

No problem, the Prime blue can be serviced afloat in a matter of hours. Just inflate the emergency seal (and for a second barrier use dive assistance to cofferdam the Sterntube) then swap out the seal ring. Note that the spare is carried on the shaft, so no specialist hot bonding equipment required.

Does my forced seawater lubrication to the seal require filtration?

Yes, we recommend 150-micron filtration.

I would like to fit an Aegir Prime Blue seal but don’t want to pull the tail shaft. Is this possible.

Yes. The Prime Blue can be supplied split. That means every component is split and ready to be assembled ‘around the shaft’.

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Our team of technical experts offer industry-leading consultation services, equipment sales and support and with a wealth of project management and technical experience, we plan and deliver. We work with you to ensure a smooth project from design specification to onsite installation. Our impartial guidance and multi-supplier approach mean we are focused on finding you the best solution meaning you can be confident in both our services and products.

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