1. Introduction
A steel flange is a forged or cast ring-shaped component designed to connect pipe sections, valves, pumps, and other equipment in piping systems. It enables critical functions such as assembly, disassembly, maintenance, and sealing, making it indispensable across industrial applications.
2. Key International Standards
Steel flanges are manufactured and tested according to globally recognized standards, which define dimensions, pressure ratings, tolerances, and materials. Key standards include:
2.1 ASME Standards (United States)
ASME B16.5: Covers pipe flanges and flanged fittings for sizes NPS ½" to 24", with pressure classes such as 150, 300, 600, 900, 1500, and 2500.
ASME B16.47: Governs large-diameter steel flanges (NPS 26" to 60") and includes Series A (MSS SP-44) and Series B (API 605).
ASME B16.36: Specifies orifice flanges for flow measurement.
ASME B16.48: Covers line blanks used for isolation.
2.2 EN Standards (European Union)
EN 1092-1: Specifies types, dimensions, and materials for circular flanges (PN 2.5 to PN 400).
DIN Standards: e.g., DIN 2527, 2573, 2576, and 2631–2638 for specific flange types and pressure ratings.
PN vs. Class: European Pressure Number (PN) (e.g., PN6, PN10, PN16) corresponds to nominal pressure ratings in bar.
2.3 Other Regional Standards
JIS (Japanese Industrial Standards): e.g., JIS B2220 for steel pipe flanges.
GB Standards (China): e.g., GB/T 9112–9124 series.
ISO 7005-1: Combines ASME and DIN dimensions for international compatibility.
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