Review of Bonded Rubber Flexible Hose Design Codes and Guidelines in Relation to Sea Water Intake Risers on FPSO Vessels

Abstract

Abstract Sea Water Intake Risers (SWIR) used on Floating Production Storage and Offloading (FPSO) vessels generally comprise of a series of bonded flexible rubber hose sections suspended as a free hanging cantilever from the underside of the vessel, a configuration unique to this application. This paper identifies the industry codes and guidelines associated with the design and manufacture of bonded flexible rubber hoses and determines those most appropriate for a SWIR application to assure the satisfactory operation and life in field. The associated industry codes and guidelines are analysed and critically appraised to determine which provide the most relevant verification and validation criteria for the design and manufacture of bonded flexible rubber hoses used in a SWIR application with due consideration given to the specific requirements of these bonded flexible rubber hoses which, in addition to the transportation of untreated seawater, also need to accommodate the loads induced by self-weight, vessel motion and environmental forces. The paper concludes that there are a number of industry codes and guidelines related to the design and manufacture of bonded flexible rubber hoses. However, whilst there are criteria from several of these industry codes and guidelines that may be applied, the design and manufacture of bonded flexible rubber hoses for a SWIR application is not specifically covered by the scope of any one of the documents reviewed. Consequently, the paper identifies the most relevant criteria from the reviewed documents and sets out a propped methodology to verify and validate the design and manufacture of a flexible hose in a SWIR application. Although this paper proposes a set of verification and validation criteria specifically intended for the design and manufacture of bonded flexible rubber hoses used for SWIR applications on FPSO vessels, it should be noted that these systems are also currently being considered by several stakeholders for similar application on the emerging Floating Liquefied Natural Gas (FLNG) vessels.