ASME B16.5 FLANGE

ASME B16.5 is a standard developed by the American Society of Mechanical Engineers (ASME) that specifies the dimensions, materials, and pressure-temperature ratings for flanges and flanged fittings used in piping systems. This standard covers flanges from 1/2 inch to 24 inches nominal pipe size (NPS) and is applicable to various types of flanges, including slip-on, weld neck, blind, threaded, and socket weld flanges.ASME B16.5 Flanges OverviewTypes of Flanges Covered:1. Weld Neck Flanges:o Designed to be welded to a pipe.o Provides a gradual transition from the pipe to the flange, reducing stress concentrations.o Often used in high-pressure and high-temperature applications.2. Slip-On Flanges:o Slip over the pipe and then are welded both inside and outside.o Easier to align and install, often used for lower-pressure applications.3. Blind Flanges:o Used to close the end of a pipe or a valve.o Provides a seal to contain pressure within a system.4. Threaded Flanges:o Have internal threads that match the external threads of the pipe.o Used where welding is not possible or practical.5. Socket Weld Flanges:o The pipe is inserted into the flange and then welded around the socket.o Suitable for high-pressure applications where a strong and tight connection is needed.Pressure-Temperature Ratings:Flanges are classified according to pressure-temperature ratings, which are designated by the flange class. The pressure-temperature ratings are designed to match the pressure and temperature capabilities of the flanges for different materials. Common classes include:• Class 150• Class 300• Class 400• Class 600• Class 900• Class 1500• Class 2500These classes define the maximum pressure the flange can handle at a given temperature.Material Specifications:ASME B16.5 specifies materials for flanges, including:• Carbon Steel: ASTM A105, ASTM A350 LF2• Alloy Steel: ASTM A182 F5, F9, F11, F22• Stainless Steel: ASTM A182 F304, F304L F316, F316L• Duplex and Super Duplex Stainless Steel: ASTM A182 F51, F53, F55• Nickel Alloys: ASTM B564 (Inconel, Monel, Hastelloy)Dimensions and Tolerances:ASME B16.5 provides detailed dimensions and tolerances for each flange type and size. Key dimensions include:• Flange Diameter: The overall diameter of the flange.• Bolt Circle Diameter: The diameter of the circle that the bolt holes are drilled into.• Bolt Hole Diameter: The diameter of the bolt holes.• Thickness: The thickness of the flange.• Raised Face: The height of the raised face for flanges with a raised face design.Equivalent Standards and ReferencesWhile ASME B16.5 is widely recognized in the US, there are equivalent standards used internationally:• ISO 7005-1: Flanges and their joints - Part 1: Steel flanges• EN 1092-1: Flanges and their joints - Flanges - Part 1: Steel flangesSummaryASME B16.5 is a comprehensive standard that ensures the proper design, materials, and dimensions for flanges used in various piping systems. It provides detailed requirements for flange types, materials, pressure-temperature ratings, and dimensions, ensuring that flanges meet the needs of different applications and operating conditions. For specific applications, always refer to the latest edition of the standard and consult with suppliers or engineers to ensure compliance and proper selection.