Section 3 Hydraulic cylinder
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 5 Main and Auxiliary Machinery - Chapter 18 Elevating Wheelhouse Systems - Section 3 Hydraulic cylinder

Section 3 Hydraulic cylinder

Parent topic: Chapter 18 Elevating Wheelhouse Systems

3.1 Hydraulic cylinder

3.1.1 Hydraulic cylinders are to be designed in accordance with the relevant requirements of Pt 5, Ch 9 Pressure Vessels other than Boilers for Class 1 pressure vessels (notwithstanding any exemptions for hydraulic cylinders).

3.1.2 Accumulators, if fitted, are to comply with the relevant requirements of Pt 5, Ch 9 Pressure Vessels other than Boilers.

3.1.3 The welding details and welding procedures are to be approved. All welded joints within the pressure boundary or connecting parts transmitting mechanical loads are to be full penetration type or of equivalent strength.

3.1.4 The construction is to be such as to minimize local concentrations of stress.

3.1.5 The design pressure for calculations to determine the scantlings of piping and other components subjected to internal hydraulic pressure shall be at least 1,2 times the maximum working pressure to be expected under normal operating conditions.

3.1.6 Actuator oil seals between moving parts, forming part of the external pressure boundary, are to be provided with a single pressure seal plus a wiper seal. Alternative arrangements providing equivalent protection against leakage may be accepted.

3.1.7 The design of synchronised telescopic cylinders is to be such that the working pressure in each compartment shall not exceed the design pressure of that compartment under all conditions of service, otherwise each compartment is to be provided with a safety relief valve discharging to atmospheric pressure.

3.2 Allowable stresses hydraulic cylinder

3.2.1 The permissible primary general membrane stress is not to exceed the lower of the following values:

or
where
σB = specified minimum tensile strength of material at ambient temperature
σy = specified minimum yield stress or 0,2 per cent proof stress of the material, at ambient temperature
= A and B are given by the following table:
  Wrought steel   Cast steel   Nodular cast iron
A 3,5   4   5
B 1,7   2   3
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