Section 2 Plans and data
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 3 Functional Unit Types and Special Features - Chapter 12 Riser Systems - Section 2 Plans and data

Section 2 Plans and data

Parent topic: Chapter 12 Riser Systems

2.1 General

2.1.1 Sufficient plans and data are to be submitted to enable the design to be assessed and approved. The plans are also to be suitable for use during construction, installation, hydrotesting, survey and maintenance of the riser system.

2.1.2 In general, engineering drawings and documents should be submitted electronically.

2.2 Specifications

2.2.1 Adequate design specifications, appropriate in detail to the approval required, are to be submitted for information.

2.2.2 Specifications for the design, construction and fabrication of the riser system, structure and associated equipment are to be submitted. The specifications are to include details of materials, grades/standards, consumables, construction and installation procedures and modes of operation with applicable design criteria. The specifications are also to include the proposed design codes.

2.2.3 Specifications and documentation are to be submitted, covering all instrumentation and monitoring systems proposed to cover the fabrication, installation and operating phases of risers, fittings and equipment.

2.3 Plans and data to be submitted

2.3.1 Plans and data covering the following items are to be submitted for approval, as relevant:
  • Bend stiffeners.
  • Bend stiffeners latching mechanisms.
  • Bend restrictors.
  • Buoyancy arches and fittings.
  • Buoyancy modules.
  • Construction and laying procedures.
  • Corrosion protection system.
  • Curvature bending stiffeners.
  • Details of all attachments.
  • Details of riser system control and communications.
  • Details of sea bed.
  • Emergency shut-down system and other safety devices, including pressure transient (surge) relief.
  • End fittings.
  • Instrumentation and communication line diagrams.
  • Layout of risers and associated platform arrangements, including protection of risers.
  • Leak detection system and hardware.
  • Location survey showing name, latitude and longitude of terminal locations, location of isolating valves, position of platforms or other fabrications, shipping channels, presence of cables, pipelines and wellheads, etc.
  • Mid water arches
  • Quality Control and NDE procedures.
  • Riser dimensions.
  • Riser material specifications, including appropriate test results.
  • Riser support details.
  • Riser wall thickness tolerances.
  • Sizes and details of expansion loops, reducers, etc.
  • Test schedules for communication systems, controls, emergency shut-down systems and other safety devices, which are to include the methods of testing and test facilities provided.
  • Tether arrangements
  • Type and thickness of corrosion coating.
  • Type and details of all pig traps, valves and control equipment, etc.
  • Welding specification, details and procedures.
2.3.2 The following supporting plans and documents are to be submitted:
  • Reference plans and listing of standard components, e.g., tees, reducers, connectors, valves, elbows, etc.
  • Reference plans of anodes, sleeves, etc.

2.4 Calculations and data

2.4.1 The following is to be submitted where relevant to the riser system:
  • Analyses of riser system behaviour including: strength, buckling, vortex shedding, on-bottom stability, displacements, vibration, fatigue, fracture and buckle propagation and minimum bend radii.
  • Buoyancy and stability data for all risers.
  • Burst pressure of flexible risers.
  • Calculations and documentation of all design loads covering: manufacture, installation and operation.
  • Corrosive nature of line contents.
  • Corrosive nature of sea-water and sea bed soils.
  • Current, tidal current and storm surge velocities and directions.
  • Design cathodic protection potential.
  • Damaging tension of flexible risers.
  • Design life.
  • Design pressure and temperature.
  • Design throughput.
  • Fluid to be conveyed. (The maximum partial pressure and dew point of , and for gas risers).
  • Ice conditions, which may affect riser system.
  • Leak detection accuracy and response.
  • Maximum and minimum operating temperatures including distributions along the riser.
  • Maximum and minimum temperatures of water and air.
  • Maximum operating pressure.
  • Maximum Excursion Envelopes (MEEs) for riser system (in the x, y and z axes) to prevent damage. MEEs to be provided in the operational and survival conditions, with the mooring system in connected and disconnected (where appropriate) conditions.
  • Marine growth density and thickness profiles (varying with water depth) plotted against time, over the field life.
  • Product density.
  • Sea bed geology and soil characteristics including stability and sand waves, etc.
  • Sea bed topography and bathymetry in way of riser system and any possible deviation or future development.
  • Seismic activity survey.
  • Test pressure to be applied.
  • Type, activity and magnitude of marine growth predicted.
  • Wave heights, periods and directions.
  • Wind velocities and directions.

2.5 Operations Manual

2.5.1 The allowable modes of operation including the maximum and minimum internal pressure, product temperature and flow rate together with the operating and maximum environmental criteria on which classification is based are to be stated in the unit's Operations Manual, as required by Pt 3, Ch 1, 3 Operations manual.

2.5.2 The Manual is to contain instructions and guidance on any actions which need to be taken to satisfy environmental considerations and the safe operation of the riser system.

Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.