English to Russian Tech/Engineering Ships, Sailing, Maritime stern tube sealing

Non-split type FWD seal
When the forward seal arrives at the shipyard its liner is assembled into the housing by 3 to 6 small bolts.

The alignment of the forward liner is critical as there are no ****spigot fits**** on the shaft to centre it automatically.
Check the accuracy of the stern tube surface in accordance with paragraph 10.1
Slide the forward seal assembly with the o-ring and the clamp-ring along the shaft.
Because of the small clearance between the forward liner and the shaft, the housing is already centred to the shaft.

Спасибо!