Oil lubricated carosel
Wärtsilä Airguard seal
The Wärtsilä Airguard OLS4A

Wärtsilä Airguard OLS4A

The Wärtsilä Airguard is an anti-pollution lip type seal, which is especially designed for applications where extra security against the leakage of oil into the seawater is required.

The Wartsila Airguard completely separates the stern tube oil and the seawater by an air barrier. Any seawater and/or oil entering the air barrier chamber is automatically drained inboard without leaking outboard or entering the stern tube.

Wärtsilä Airguard takes away successfully the oil-to-sea- interface, it can be operated with mineral oil with regards to the US VGP2013. The seal is available for any shaft size between 450 and 1250 mm. Installation is easy, and the seal can be retrofitted to almost any stern tube.


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Long service intervals 
With no maintenance between planned overhauls the Wartsila Airguard allows 7.5 years docking cycles. 
Anti-pollution seal
The Wärtsilä Airguard is a multi-barrier lip seal containing three or four seal rings. Two seal rings face the stern tube oil side and provide active double security against oil spill. The seal ring on seawater side separates air and water with no load on it.
Protected seal ring
The seal ring is protected by P-ring designed to prevent fishing nets or ropes from damaging the seal and causing unscheduled dry docks.


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