Dave Steel here. New to the forum, long time visitor to the site.
Since installation of the alfa laval SU 821 separators onboard, we have found damaged discs during disassembly of the bowl. This includes the first disassembly after installation. (came from factory this way) The first time was warrantied. However, we continue to find the first
3-4 discs damaged at the vertices of the indexing notches. They are rolled up on one side only. I must stress that extra care has been taken since we initially discovered this. Yet despite this care and strict adherence to alfa lavals instruction, it keeps occurring. I even went as far as using a dial indicator to ensure compression of the hood was within a couple thou during each turn of the screws.
regardless, the discs were being damaged. since 2008, chiefs, down to 3rds have experienced this issue. doesn't seem to matter who does it or the diligence assumed. we run diesel only through these units and only from reputable sources along BCs coast. The units are in very good shape otherwise. Furthermore, Alfa Laval states in the manual that during disassembly, the compression screws must not exceed 60Nm when compressing the hood. Then during assembly, its 40Nm. And finally under "checking stack pressure" it states 50Nm. We have Ideas regarding the difference in torques but seek other opinion. Has anyone seen this or have any ideas? This is happening on both units so I don't believe this to be an isolated incident.