Det Norske Veritas - Germanischer Lloyd

DNVGL  Synthetic bearing bushing materials
 N DNVGL-CP-0081

Annotation

This CP gives a description of the procedures and requirements related to documentation, design and type testing applicable for TA of synthetic bushing materials for rudder bearings and propeller shafts.

This CP does not set the design requirements for synthetic bushing materials for rudder bearings and propeller shafts. TA is based on compliance with design requirements given in the rules and/or other regulations and standards. The CP describes the applicable requirements and how to document compliance with the requirements in order to obtain a TA certificate for the equipment. This includes, where relevant, technical requirements for how the type tests shall be performed.

The type approval certificate will cover one grade of the actual product with the possibility to include variants.

For synthetic bushing materials this means:

grade: one chemical composition, with our without reinforcements

variants: various dimensions

Synthetic bushing materials using different chemical compositions, resins, fibres, filler material etc. are considered to be different grades.

The Society's type approval for a synthetic bushing material is divided into four different main levels based on the bushing material’s capability to withstand surface pressure in operational condition:

5.5 N/mm2 = type testing according to Sec.2 Table 1 and Sec.2 Table 2.

7.5 N/mm2 = type testing according to the general scheme: Sec.2 Table 1, plus testing of swell (dry/ wet/dry/wet cycles) and wear testing at increased pressure: Sec.2 Table 3.