Section 4 Materials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 7 Piping Systems - Chapter 1 Piping Design Requirements - Section 4 Materials

Section 4 Materials

Parent topic: Chapter 1 Piping Design Requirements

4.1 Metallic materials

4.1.1 Materials for Class I and II piping systems and components as defined in Table 1.2.1 Classes of piping system, also for shell valves and fittings and fittings on the collision bulkhead, are to be manufactured and tested in accordance with the Rules for the Manufacture, Testing and Certification of Materials, July 2022

4.1.2 Materials for metallic castings and forgings for Class I and II piping systems are to be produced at a works approved by Lloyd’s Register (commonly referred to as ’LR’) and are to be tested in accordance with the Rules for the Manufacture, Testing and Certification of Materials, July 2022

4.1.3 Materials for Class III piping systems are to be manufactured and tested in accordance with the requirements of acceptable National Standards.

4.1.4 The Manufacturer’s materials certificate will be accepted in lieu of an LR materials certificate for Class III piping systems and for all other classes of piping and associated components where the maximum design conditions are less than the values shown in Table 1.4.1 Maximum conditions for pipes, valves and fittings for which Manufacturer's materials test certificate is acceptable. See Ch 1, 3.1 General 3.1.3.(c) of the Rules for Materials.

Table 1.4.1 Maximum conditions for pipes, valves and fittings for which Manufacturer's materials test certificate is acceptable

Material DN = Nominal diameter, mm

P w = Working pressure, bar

When the working temperature is less than 300°C: Carbon and low alloy steel, austenitic stainless steel and cast iron (spheroidal or nodular) DN < 50orP w × DN < 2500
Copper alloy intended for a working temperature of less than 200°C DN < 50orP w × DN < 1500

4.1.5 The Manufacturer's certificate for materials for ship-side valves and fittings and valves on the collision bulkhead equal to or less than 500 mm nominal diameter will be accepted in lieu of LR's materials certificate where the valves and fittings are in accordance with a recognised National Standard applicable to the intended application and are manufactured and tested in accordance with the appropriate requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

4.2 Non-metallic materials

4.2.1 Pipes and fittings intended for applications in Class I, Class II and Class III systems for which there are Rule requirements are to be manufactured in accordance with Ch 14 Plastics Materials and other Non-Metallic Materials of the Rules for Materials.

4.3 Dissimilar materials

4.3.1 Where materials vary for individual pipes and components that are joined in the presence of a conductive fluid they are either to be compatible, or electrically isolated, in order to avoid galvanic corrosion.

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.