4AE3 U3 C3 Obj 4.pdf

Codes and Standards for Power Engineers and Pressure Vessels • Chapter 3 Objective 4 Explain the content and use of ASME Boiler and Pressure Vessel Code (ASME BPVC) Section I Power Boilers. Section I: Rules for Construction of Power Boilers Power boilers are defined as boilers in which steam or ot...

Codes and Standards for Power Engineers and Pressure Vessels • Chapter 3 Objective 4 Explain the content and use of ASME Boiler and Pressure Vessel Code (ASME BPVC) Section I Power Boilers. Section I: Rules for Construction of Power Boilers Power boilers are defined as boilers in which steam or other vapour is generated at a pressure greater than 100 kPag. This also includes boilers that produce hot water above 120°C. ASME Section I contains the rules and general requirements for all methods of construction for power boilers used in stationary service. Its scope also includes power boilers used in locomotive, portable and traction service. The PanGlobal ASME Academic Extract contains the sections of ASME I most referred to by Power Engineers. Contents of ASME I ASME I is divided into several parts, each of which addresses a particular aspect of boiler design and construction. All parts in ASME Section I are prefixed with the letter “P” for “Power.” These Parts are: • Part PG General Requirements for all Methods of Construction • Part PW Requirements for Boilers Fabricated by Welding • Part PR Requirements for Boilers Fabricated by Riveting • Part PB Requirements for Boilers Fabricated by Brazing • Part PL Requirements For Locomotive Boilers • Part PWT Requirements for Watertube Boilers • Part PFT Requirements for Firetube Boilers • Part PFH Optional Requirements for Feedwater Heater • Part PMB Requirements for Miniature Boilers • Part PEB Requirements for Electric Boilers • Part PVG Requirements for Organic Fluid Vaporizers • Part PFE Requirements for Feedwater Economizers • Part PHRSG Requirements for Heat Recovery Steam Generators As well, ASME I has a set of Mandatory Appendices and Non-Mandatory Appendices to provide details on application of the code. The PanGlobal ASME Academic Extract contains the most relevant Code sections for Power Engineers. ASME has used a “soft” conversion for most of the conversions between SI units and USCS (United States Customary System). Table 1 – ASME Conversions Imperial Soft Conversion Hard Conversion 15 PSI 100 kPa 103.0 kPa 250 o F 120°C 121°C 14.7 psi 160 psi 101.3 kPa 1100 kPa 1103 kPa 4th Class Edition 3 • Part A 3-13 Unit A-3 • Introduction to Power Engineering and its Governance in Canada The scope of ASME Code Section I covers superheaters, economizers, and other pressure parts connected directly to the boiler with no intervening valves. These parts are referred to as Boiler External Piping. ASME I does not address any other steam, blowoff or feedwater piping. Part PG - General Requirements for All Methods of Construction Part PG covers the fundamentals of all power boiler designs. This part deals with: a) Materials used for boilerplate, forgings, castings, pipes, and tubes. b) Basic design calculations for cylindrical parts under internal pressure. This includes shells, drums, headers, and boiler piping. c) Basic design calculations for cylindrical parts under external pressure. This includes furnace tubes and firetubes. d) Dished and flat heads. e) Requirements for reinforcing openings in shells, heads, and headers. f ) Methods of attaching pipes and nozzles to vessel walls. g) Inspection openings and stayed surfaces. h) Requirements for miscellaneous pipe, valves, and fittings. i) Requirements for feedwater supply. j) Requirements for boiler and superheater pressure relief valves. This includes mounting, testing, capacity, set point, and operation of pressure relief valves. k) Fabrication rules for the cutting and identification of plate, defects in materials, tube holes and tube ends, and holes for threaded stays. l) Rules for the qualifications of inspectors. m) Procedures for hydrostatic tests. n) Details for the stamping of boilers, pressure piping, and pressure relief valves. Part PW - Requirements for Boilers Fabricated by Welding This part covers general rules for welded boilers. a) Materials of construction. b) Design of welded joints, heat treatment, radiographic and ultrasonic examination of welds. c) Weld efficiencies, opening adjacent to welds, and minimum requirements for attachment welds. d) Rules for fabrication. This includes welding processes, welding qualifications, base metal preparation, and assembly. e) Preheating, post-weld heat treatments, and repair of weld defects. Part PWT - Requirements for Watertube Boilers This part deals with specific rules for design and construction of watertube boilers. These specific rules are used together with the general rules of Part PG. 3-14 4th Class Edition 3 • Part A Codes and Standards for Power Engineers and Pressure Vessels • Chapter 3 Part PFT - Requirements for Firetube Boilers This part deals with specific rules for the design and construction of firetube boilers. These specific rules are used together with the general rules of Part PG. a) Design rules for minimum thicknesses and maximum allowable working pressures of tubesheets, reinforced and corrugated furnaces, stayed surfaces, and waterlegs. b) Furnace and tube attachment. c) Inspection openings, access, and firing doors. d) Steam domes, settings, fittings, feedwater piping, and blowoff piping. Part PFH - Requirements for Feedwater Heaters This short part defines a feedwater heater falling within the scope of Section I, and discusses its design requirements. These specific rules are used together with the general rules of Part PG. The PanGlobal ASME Academic Extract does not include this section. Part PMB - Requirements for Miniature Boilers Miniature high-pressure boilers are typically of such low capacity that they do not require licensed operators. These specific rules are used together with the general rules of Part PG. The PanGlobal ASME Academic Extract does not include this section. Part PEB - Requirements for Electric Boilers In this Part, electric boilers are defined. It deals with specific rules for design and construction of electric boilers. Specific design rules are discussed for: • Welding • Inspection openings • Pressure gauges • Pressure relief valves These specific rules are used together with the general rules of Part PG. The PanGlobal ASME Academic Extract does not include this section. Part PVG - Requirements for Organic Fluid Vaporizer Generators Organic Fluid Vaporizers are similar to steam boilers. However, they boil hydrocarbon-based fluids to produce high-pressure vapour. This Part has general rules for the materials and design of organic fluid vaporizers. There are specific rules for level gauges, pressure relief valves, and rupture discs. These specific rules are used together with the general rules of Part PG. The PanGlobal ASME Academic Extract does not include this section. Appendices The Mandatory Appendices provide additional information. These are necessary to properly apply the code. The Non-Mandatory Appendices also provide additional information. However, they are only required when specifically referred to in the rules of the code. The Mandatory Appendices cover topics such as: a) Standard units for use in equations b) Local thin areas in cylindrical shells and heads c) Additional rules for boilers fabricated by riveting 4th Class Edition 3 • Part A 3-15 Unit A-3 • Introduction to Power Engineering and its Governance in Canada The Non-Mandatory Appendices cover topics such as: a) b) c) d) e) f) g) h) 3-16 Efficiency of riveted joints Method of checking pressure relief valve capacity Use of automatic water gauges Fusible plugs Acceptance criteria for welds Manufacturer’s Data Reports Repairs to existing boilers Reinforcement calculations for openings in vessels 4th Class Edition 3 • Part A