This document was produced by Aquamarine Power Ltd in 2014 to record good practice for the specification of bolted connections on the Oyster 800 device, built up through experience of operation and offshore maintenance campaigns during the summers of 2013 and 2014.

Oyster 800 was installed at EMEC over 2011 to 2012 before undergoing a series of commissioning and operating trials. One area of concern was the long-term integrity of mechanical connections on the machine, which include a number of bolted and flanged connections of various sizes and functions. Operational experience shows that mechanical connections are prone to both corrosion and loosening, caused primarily by vibration.

The purpose of this document is to outline guidance to apply good design practice for threaded connections, specifically with respect to material selection and assembly techniques. The standard applications considered in this document are structural connections, hydraulic flanges, retaining fasteners, jacking screws and hydraulic fittings.

Project Keywords: Hydraulics, Materials, Operations & Maintenance, Corrosion, Engineering, Bolting