Section 1 General

1.1.1 The requirements of this Chapter apply to the welding of pressure vessels and process equipment, heating and steam raising boilers and pressure pipes. The allocation of Class is determined from the design criteria referenced in Vol 2, Pt 7, Ch 1 Piping Design Requirements and Vol 2, Pt 8 Pressure Plant.

1.1.2 Fusion welded pressure vessels will be accepted only if manufactured by firms equipped and competent to undertake the quality of welding required for the Class of vessel proposed. For Class 1, 2/1 and 2/2 pressure vessels, the manufacturer's works are to be approved in accordance with the requirements specified in Materials and Qualification Procedures for Ships, Book A Procedure MQPS 0-4.

1.1.3 For pressure vessels which only have circumferential seams, see Vol 2, Pt 8, Ch 1, 1.5 Classification of fusion welded pressure vessels 1.5.4 and Vol 2, Pt 8, Ch 2, 1.5 Classification of fusion welded pressure vessels 1.5.5.

1.2.1 In the first instance, and before work is commenced, the Surveyors are to be satisfied that the required quality of welding is attainable with the proposed welding plant, equipment and procedures in accordance with the guidelines specified in Materials and Qualification Procedures for Ships Book A, Procedure 0-4.

1.2.2 All welding is to be in accordance with the requirements specified in Ch 13 Requirements for Welded Construction of the Rules for the Manufacture, Testing and Certification of Materials (hereinafter referred to as the Rules for Materials).