Section 5 Piping systems
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Special Service Craft, July 2022 - Part 14 Steering Systems - Chapter 1 Steering Systems - Section 5 Piping systems

Section 5 Piping systems

5.1 Components

5.1.1 Piping, joints, valves, flanges and other fittings are to comply within the requirements of Pt 15, Ch 1 Piping Design Requirements for Class 1 piping system components. The design pressure is to be in accordance with Pt 14, Ch 1, 4.2 Actuating systems 4.2.3.

5.2 Valve and relief valve arrangements

5.2.1 For vessels with non-duplicated actuators, isolating valves are to be fitted at the connection of pipes to the actuator, and are to be directly fitted on the actuator.

5.2.2 Arrangements for bleeding air from the hydraulic system are to be provided, where necessary.

5.2.3 Relief valves are to be fitted to any part of the hydraulic system which can be isolated and in which pressure can be generated from the power source or from external forces. The settings of the relief valves is not to exceed the design pressure. The valves are to be of adequate size and so arranged as to avoid an undue rise in pressure above the design pressure.

5.2.4 Relief valves for protecting any part of the hydraulic system which can be isolated, as required by Pt 14, Ch 1, 5.2 Valve and relief valve arrangements 5.2.3 are to comply with the following:

  1. The setting pressure is not to be less than 1,25 times the maximum working pressure.

  2. The minimum discharge capacity of the relief valve(s) is not to be less than 110 per cent of the total capacity of the pumps which can deliver through it (them).

    Under such conditions the rise in pressure is not to exceed 10 per cent of the setting pressure. In this regard, due consideration is to be given to extreme foreseen ambient conditions in respect of oil viscosity.

5.3 Flexible hoses

5.3.1 Flexible hoses are to be of approved type, see Pt 15, Ch 1, 13 Flexible hoses.


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