Section 8 Boilers and other pressure vessels for the process plant

8.1.1 The requirements of this Section are applicable to fired and unfired pressure vessels associated with the process plant.

8.1.2 The pressure vessels are to be made in accordance with the requirements of the relevant Sections of Pt 5, Ch 10 Steam Raising Plant and Associated Pressure Vessels or Pt 7, Ch 2, 11 Electrical equipment for the process plant, as applicable, or with agreed codes and specifications normally used for similar plant in land installations suitably modified and/or adapted for the marine environment. The design is to be capable of accommodating the forces and moments stated in Pt 7, Ch 2, 6.7 Plant support structure, Pt 7, Ch 2, 6.8 Loading due to wave-induced motions and Pt 7, Ch 2, 6.9 Additional loads, as applicable, generated at the support points.

8.1.3 Stress calculations are to take account of the emergency conditions in Pt 7, Ch 2, 3.1 General 3.1.3 or Pt 7, Ch 2, 3.1 General 3.1.4, as applicable, in addition to the normal operational loadings. Due consideration is to be given to the effects of thermal expansion and contraction on the support points of the vessels.

8.2.1 The pressure vessels are to be constructed, installed and tested to the Surveyor's satisfaction.

8.2.2 Suitable access is to be provided to the vessels for inspection, including checks on the operation of mountings, fittings, controls and pressure relief devices.

8.3.1 Where necessary, a test rig is to be supplied to enable the pressure setting of the safety and relief devices to be checked.

8.3.2 Where required, an additional pressure relieving device, with sufficient capacity (a) to prevent pressure vessels becoming liquid-full during fire engulfment and/or (b) to discharge vapours generated under fire exposure, is to be fitted in accordance with the relevant Rules and Regulations for the Construction and Classification of Ships for the Carriage of Liquefied Gases in Bulk, July 2022.

8.3.3 The arrangement of safety and relief discharges is to be such that there is no possibility of hazardous reaction between the substances involved.

8.3.4 Where provision is made for the isolation of safety relief devices from vessels and/or systems for maintenance purposes, not less than two such safety devices are to be fitted.

8.3.5 The isolating or blocking valves are to be so arranged that at least one safety relief device will remain in communication with the vessel or system under all conditions.