Large Diameter Flanged Connection Make-Up With Zero Reworks

Abstract Subsea installations of large diameter flanged connections can prove to be costly and dangerous. The use of Taper-Lok connectors for subsea make-up of tie-ins and manifold connections during the installation of the BP Bombax Pipeline Project provided safer and faster connection make-up times, damage resistance, reduction of weight and one time, leak free installation. This paper will outline the reasoning behind the use of the Taper-Lok connection for this project and the areas of cost savings associated. Introduction The subsea pipeline portion of the BP Trinidad Bombax Project called for flanged connections to be used in 20-inch, 26-inch and 48-inch sizes. These were to be provided in Weld Neck, Swivel, Blind Flange and Misalignment designs. The need for ease of make-up at depths of 300 feet, in waters with limited visibility, high current loads and heavy weight considerations were driving forces in the connections to be used. Due to stringent BP policies, safety during installation was a major consideration, as well. Discussions began in mid March of 2001 regarding the manufacturing of the required connections. Preliminary design requirements were developed and the Taper-Lok engineering phase began in early April. Taper-Lok offers a full range of product groups. All product groups have features, which are common elements, and several of the products offer additional, unique features and time saving devices. Design Criteria and Requirements General. Operating Conditions.External Hydrostatic Pressure = 300 feet water depthOperating Max. Seawater Ambient Temp. = +80 deg FMin. Blow Down Temp. = +14 deg FMax. Internal Operating Pressure = 1480 psigHydrostatic Test Pressure = 1.5 times operating pressureOperating Temp. = 150 deg F Taper-Lok was selected due to the following inherent design features:Sealing Integrity;Self Alignment During Make-Up;Size and Weight Reduction;Safety During Installation;Forgivingness of Sealing Surfaces;Misalignment Capabilities.Annulus Test Port Capability.Meets or exceeds the requirements of ASME Section VIII, Division 1 and 2, API 6A, ANSI, and MSS flange design standards.Self-Energized/Pressure Energized, Reusable, Seal Ring.Smaller/Lighter Bolts Flange Requirements. Size Description Qty. 48" Weld Neck Flanges 12 48" Swivel Flanges 8 48" Blind Flanges 11 26" Weld Neck Flanges 16 26" Swivel Flanges 11 26" Blind Flanges 13 20" Weld Neck Flanges 11 20" Swivel Flanges 4 20" Blind Flanges 7 48" 5°?Misalignment Connectors 2 26 10°Misalignment Connectors 3 Total 98 Various Sizes Studs with 2 Nuts ea. 2,700 +