Umbilical Termination Head (UTH)

3.3.3. Umbilical Termination Head (UTH)

The UTH, shown in Figure 3-4, consists of a structural frame, hinging stab, MQC plates, super-duplex tubing, and bulkhead style ROV electrical

connectors. Umbilical services are routed to the MQC plates and electrical connectors for distribution to subsea production equipment. The SUTA terminates the hydraulic subsea umbilical and provides a flange connection to attach the umbilical termination. The umbilical is composed of super-duplex tubes. All tubing in the UTH and HDM is welded to the hydraulic couplers located within the MQC plates. The number of welded connections between the couplers and the tubing is kept at a minimum. Butt-weld joints are preferred over socket-welded connections. The design allows for full opening through the tubing and the welded area. The design also avoids any area where crevice corrosion may occur. The termination flange connection between the SUTA and the umbilical is designed to accomplish the following condition: • Because the SUTA is installed with its stab and hinge-over stinger, the flange is capable of supporting the weight of the SUTA as well as all installation loads. • After installation, the SUTA may need to be lifted from its mudmat and stab and hinge-over funnel. As the SUTA is lifted and brought back to the surface, the flange is capable of supporting the “unsupported” umbilical weight with a 50% safety factor. The UTH at minimum complies with the following requirements: • At minimum, the UTH is designed to allow termination of a minimum of nine umbilical steel tube lines and two electrical quads. • The structural frame is designed to securely attach to and support the umbilical and end termination as well as provide mounting locations for the MQC plates and bulkhead electrical connectors. • The hinging stab is attached to the frame and is the interface between the UTH and mudmat structure. • The UTH frame size is minimized in order to simplify handling and overboarding. • The UTH are kept small to fit inside most umbilical overboarding chutes, and can be maneuvered through most vessel umbilical handling systems. • The recovery padeyes are designed to take the full recovery load of the UTH and the umbilical. • The UTH, combined with the umbilical split barrel (supplied by the umbilical manufacturer), is designed to sit on the umbilical reel of an installation vessel at the end and/or at the beginning of the umbilical. • Tubing connections and other possible points of failure are reduced as much as possible in the UTH to avoid having to retrieve the umbilical to repair a failed component.