API TR 17TR7-2017 pdf download.Verification and Validation of Subsea Connectors.
3.1.8 external loads Includes global load effects like axial loads, bending moment, torque, and shear. 3.1.9 finite element analysis FEA Numerical method for analyzing dynamic and static response by dividing the structure into small continuous elements with the given material properties. NOTE The analysis can be local or global. 3.1.10 fracture mechanics Assessment and analysis where critical defect sizes under design loads are identified to determine the crack growth life, i.e. leak or fracture. 3.1.11 functional capacity Loading condition where the functional failure criteria specified for the component is met but not exceeded. 3.1.12 hub face separation Separation is defined as zero contact forces between the mating hubs (from ID to OD) on the tension side of the applied load condition. 3.1.13 leak tightness capacity Maximum load combination that may reliably be applied before leakage occurs in the connector. 3.1.14 load, extreme Conditions that include the unavoidable but predictable load conditions due to the environmental and operating scenarios. 3.1.15 load, normal Conditions that corresponds to a design factor of 0.67 with respect to SMYS. 3.1.16 load, survival Conditions which include the unplanned, unavoidable, and unpredictable load conditions due to the environmental, operating, or any other scenarios. NOTE 1 Also referred to as accidental load. NOTE 2 Survival loads of a component means that the component does not fail but it can present one or more kinds of degradations that may impact its specified performance or service life.
4 General 4.1 Purpose The aim of the connector design is to ensure that the connector has adequate structural capacity, leak tightness, fatigue performance, and functionality for all relevant load cases. Resistance against survival (accidental) loads shall be considered in the design process. Connectors shall be qualified for the application based on verification analysis in combination with validation testing. The manner in which the pressure-containing body is connected to adjacent bodies above and physically locked to the mating profile hub below is key to the overall performance of a connector. Various types of interfaces can be used to assemble and mount a connector to an adjacent assembly. This interface could be a clamp style, collet style, flanged, or a threaded connection. The capacity of each connector shall be provided independently of adjacent connectors (e.g. the wellhead connector will be rated independently of the adjacent flanged connection). The connector performance validation testing program shall consist of verification analysis and full-scale testing. The combined load capacities shall be defined by design verification calculations. Full-scale testing shall be performed to validate the verification analysis results and to explore performance parameters that are not easily quantified through calculations, e.g. preload loss and leak tightness. Once testing is complete, test and analysis results shall be compared as part of the design documentation. If there is a crucial discrepancy in the results in critical areas, the analysis shall be studied and changes shall be made to the analysis or test program. Consideration shall be given for re-analyzing or re-testing, whichever be the case, after careful evaluation of the results. If discrepancies between analysis and testing are not resolved, the test results shall override the analysis.
4.2 Connector Descriptions Subsea connectors are mechanical devices used to connect adjacent components in the system to create a structural joint that resists applied loads and prevents leakage. Specific connector types covered by this document are as follows. a) Hydraulic connectors: mechanical connectors that are activated hydraulically. b) Flanged connectors: bolted flange connections designed for face-to-face contact including two flanges, bolts, and gasket/seal ring(s). c) Radial bolt connectors: dog-type connectors where dogs act as wedges mechanically driven between the box and pin for engagement and include gasket/seal ring(s). d) Collet connectors: collet-type connectors that have a slotted cylindrical element joining mating connector members and include gasket/seal ring(s). e) Clamp connectors: clamped hub types designed for face-to-face contact including two hubs, clamps, bolts, and gasket/seal ring(s).