Stern tube sealing arrangement in ship

Structure

1)The aft seal consists three major parts that is a) 4 rubber seal rings b) metal housing holding the rubber seal ring c) and eyeliner which rotates together with the propeller shaft  . Metal housing is made up in order from the stern frame side of an aft flange casing, an aft intermediate ring a, an aft intermediate B,an aft intermediate ring c, and a split type aft seal cover . The rubber seal  are inserted between this metal rings and bolted together. The clamp section of each seal ring is securely fitted to the metal rings inner circumference and to the small grooves on the inner side of the metal ring,so that the clamp  part is made oil and water tight. The material of the liner is highly resistant to corrosion and wear.

 2) forward seal consists of major parts that is a) 2rubber seal ring, b)a metal housing holding the rubber seal ring c) liner which rotates together with the propeller shaft d)and clamper ring which hold the liner.
 The metal housing is made up from aft to fore,  a forward flange casing, a forward intermediate ring and forward seal cover.
As in the case of aft seal, the metal ring of the forward Seal are bolted together so that the rubber seal can be readily clamped and assembled . The material of the liner features excellent wear resistant and lip lubricating properties.

Lube oil sytem
 Since the lube oil system of each ship vary with the ship types and draught and shipyard standard, we recommend that system be operated in accordance with drawing provided by the yard.
 The following instruction are based on the basic ideas of lube oil system. In case of automatic control ship ,notice to add the high level alarm etc.

1)Stern tube bearing
In order to keep the lube oil pressure value higher than the sea water pressure at the centre under full load by 0.015MPA, gravity tank is provided onboard.
 For deep draught vessel two gravity tanker provided, one for use under full load (high level) and the other for ballast( low level)