The longer lifetime on the seat area is achieved with the new geometry of the W-seat, which retains the temperature reducing features of the chamber seat and combines them with the benefit of the two narrow concentric contact areas.
W-seat
The effect is that all carbon particles which are trapped between the spindle and bottom piece are crushed and squeezed out and therefore eliminated without giving rise to any appreciable risk dents.
The spindle and seat are fit for further use provided that : • There is contact along the entire inner circumference of the seat. • There are no blow-by tracks across the inner part of the seats.
Formation of dent marks is an inevitable consequence of service on heavy fuel oil. Dent marks may appear harmful, but will in general have no influence on the performance of the exhaust valve seat.
HVOF-coating
Vane wheel for gas driven spindle rotation
If indications of blow-by are found, then the seat must be ground. Base Material: Nimonic 80A
New sealing air chamber suitable for air as well as oil sealing medium
Hardened steel chamber-type bottom piece
HVOF coating on Nimonic spindles
Modified design
New tool for handling (instead of bolt assembly) 2 pcs.
Improvements:
Mechanical stop for spindle movement combined with safety valve in actuator Smaller bottom piece Cooling water connection between cylinder cover and valve housing through bores in valve housing
