As you may know, "Guidance for the Approval and Type Approval of Materials and Equipment for Marine Use" was partly amended on 2 May 2007, to require an approval test for the crankcase explosion relief valves of diesel engines installed on ships for which the date of contract for construction is on or after 1 July 2007 in accordance with IACS UR M66.
However, IACS recently amended the application of UR M66, and therefore, ClassNK has also adopted the amendment of UR M66. Accordingly, Chapter 10, Part 6 of the Guidance has been revised so that the approval test is required for either of the following crankcase explosion relief valves.

1. Explosion relief valves of diesel engines whose date of application for certification is on or after 1 January 2008 and that are installed on ships for which the date of contract for construction is before 1 January 2008.

2. Explosion relief valves of diesel engines installed on ships for which the date of contract for construction is on or after 1 January 2008.

"Application for certification" in 1. refers to the application for approval of diesel engines submitted to ClassNK by the diesel engine manufacturer for each ship.

(To be continued)