Section 3 Class of pipes
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Linkspans, July 2022 - Part 4 Engineering Systems - Chapter 4 Piping and Pressure Vessel Design Requirements - Section 3 Class of pipes

Section 3 Class of pipes

Parent topic: Chapter 4 Piping and Pressure Vessel Design Requirements

3.1 General

3.1.1 Pipework systems are divided into three classes depending on the internal fluid and design temperature and pressure of the system.

3.1.2 Material requirements for the different classes of pipe are detailed in Rules for the Manufacture, Testing and Certification of Materials, July 2022.

3.1.3 Acceptable jointing methods for the different classes of pipe are given in the appropriate Section of this Chapter. Material certificate requirements are given in Pt 4, Ch 4, 9 Material certificates.

3.1.4 The maximum design pressure and temperature for Class II and III systems are given in Table 4.3.1 Maximum pressure and temperature conditions for Class II and III piping systems

Table 4.3.1 Maximum pressure and temperature conditions for Class II and III piping systems

Piping system Class II Class III
p T p T
  MPa °C MPa °C
Flammable liquids 1,6 150 0,7 60
(see Note)        
Other media 4,0 300 1,6 200

Note Flammable liquids include hydraulic oil.

3.1.5 Class I pipes are to be used where either the maximum design pressure or design temperature exceeds that applicable to Class II pipes.

3.1.6 Class III pipes may also be used for open ended piping e.g. overflows, vents, open-ended drains, sounding pipes, etc.

3.2 Design pressure

3.2.1 The design pressure, p, is the maximum permissible working pressure and is to be not less than the highest set pressure of the safety valve or relief valve.

3.3 Design temperature

3.3.1 The design temperature, T, is to be taken as the maximum temperature of the internal fluid, but in no case is it to be less than 50°C.

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