Section 2 Structure
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 8 Process Plant Facility - Section 2 Structure

Section 2 Structure

Parent topic: Chapter 8 Process Plant Facility

2.1 Plans and data submissions

2.1.1 The following additional plans and information are to be submitted:
  • General arrangement plans of the plant layout.
  • Plans and design calculations as required for derricks in Pt 3, Ch 7, 2 Structure, when appropriate.
  • Structural plans of equipment skids and design calculations.
  • Structural plans of equipment support frames and trusses and design calculations.
  • Flare structures and design calculations.

2.2 Materials

2.2.1 Materials are to comply with Pt 3, Ch 1, 4 Materials and material grades are to comply with Pt 4, Ch 2 Materials using the categories defined in this Section.

2.2.2 Support structures for the production and process plant are to be divided into the following categories:
  • Primary structure.
  • Secondary structure.
2.2.3 Some specific examples of structural elements which are considered as primary structure are as follows:
  • Module main frame members and deck support stools.
  • Main legs and chords including end connections.
  • Foundation bolts.

2.3 Miscellaneous structures

2.3.1 The design loadings for all structures supporting plant, including equipment skids, support frames and trusses, are to be defined by the designers/Builders and calculations are to be submitted in accordance with an appropriate Code or Standard, seePt 12, Ch 1 Recognised Codes and Standards . The design requirements of Pt 3, Ch 8, 1.4 Plant design characteristics are to be complied with.

2.3.2 The design of process plant support structures should integrate with the primary hull under-deck structure.

2.3.3 The permissible stresses in the hull structure below the production and process plant are to be in accordance with Pt 3, Ch 3, 2 Structure and Pt 4, Ch 5, 2 Permissible stresses.

2.4 Flare structures

2.4.1 Flare structures are to be designed for an emergency condition and for normal operating conditions as defined in Pt 3, Ch 8, 1.4 Plant design characteristics and in accordance with an appropriate Code or Standard, see Pt 12, Ch 1 Recognised Codes and Standards.

2.4.2 The flare structures are also to be designed for the imposed loads due to handling the structure and when in the stowed position.

2.4.3 The designers/Builders are to specify the maximum weight of the burner and spreader and the design criteria defined in Pt 3, Ch 8, 1.4 Plant design characteristics.

2.4.4 The structural design of flare structures is to include the effect of fatigue loading and the thermal loads during flaring, see Pt 4, Ch 5 Primary Hull Strength.

2.4.5 Where National Administrations give specific requirements with respect to fatigue design, it is the responsibility of the Owners to comply with such Regulations.

2.4.6 For slender structures and components, the effects of wind induced cross-flow vortex vibrations are to be assessed.

2.4.7 Wind loads are to be calculated in accordance with LR’s Code for Lifting Appliances in a Marine Environment (hereinafter referred to as LAME Code) or a recognised Code or Standard, see Pt 12, Ch 1 Recognised Codes and Standards.

2.4.8 Permissible stresses in the hull structure below the flare structure supports are to be in accordance with Pt 4, Ch 5 Primary Hull Strength.

2.5 Lifting appliances

2.5.1 Lifting appliances used for handling flare structures and blow out preventers are to be in accordance with LR’s LAME Code, see also Pt 3, Ch 11 Lifting Appliances and Support Arrangements.

2.6 Guard rails and ladders

2.6.1 It is the Owners’ responsibility to provide permanent access arrangements and protection by means of ladders and guard rails. It is recommended that such arrangements are designed in accordance with a recognised Code or Standard.

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.