2025 版改了什么
变更摘要逐项列出改动位置、是新增还是修订，以及其背后的记录编号。下表按主题归类这些条目，并补充对买方或设计人员的实际影响。
| 领域 | 2025 版变更内容 | 对买方的影响 |
|---|---|---|
| Edition status | ANSI approval on 4 March 2025; issue date 30 May 2025; next edition scheduled for 2028. | Quote ASME B16.47-2025 on new orders; confirm which edition an existing drawing calls up. |
| Unit-system table titles | Titles of the complementary SI and U.S. Customary tables were editorially revised to name the applicable unit system. | It is now unambiguous which table is bar and which is psig; no rating or dimension changed for this item alone. |
| Pressure–temperature ratings | Working-pressure values and the accompanying notes were revised throughout Tables 3-28 and 3C-28C (record 23-2374). | Ratings can differ from B16.47-2020. Re-check the allowable pressure at the design temperature against the 2025 tables. |
| Group 2.13 duplex stainless | A new Table 29 / 29C was added for Group 2.13 materials (duplex and super-duplex grades). | Duplex flanges now have a dedicated rating table rather than a cross-reference; check the grade against Table 1. |
| Table 1 materials | Table 1 was revised (records 21-1888 and 23-2374). | Confirm the material group number of your grade before reading a rating table; a different group means a different table. |
| Bolting | ASTM A320-L7M was added to Table 2 and Note (5) was revised (record 22-651). | An additional low-temperature bolting option is now listed; bolting must still suit the flange material and service temperature. |
| Table 2 notes | Note (7) was deleted and the subsequent notes renumbered (record 21-1888). | If a QA document quotes a Table 2 note number, re-check it against the 2025 print. |
| Definitions | A new para. 1.13 defines 'may', 'shall' and 'should' (record 22-2279), and 'must' was replaced in two clauses. | Requirement wording is more consistent; no technical requirement changed for this item alone. |
| Metric note temperatures | In the notes to Tables 3-6, 21 and 25, metric temperatures were revised to the nearest degree (record 22-2277). | Note-level temperature limits may read slightly differently; use the rounded °C value in the 2025 print. |
| Table numbering | The new Table 29/29C displaced the later tables: dimension Tables 32-42 were formerly Tables 31-41, and the 'Minimum Thickness of Flange, t' subheadings were editorially revised. | Update drawing and specification references; a reference to 'Table 35' in an old document may now be Table 36. |
| Rating ceilings (non-mandatory) | Ceiling pressures for Classes 300-900 in Table A-1 / A-1C were revised (record 22-2110). | Affects the non-mandatory rating-ceiling appendix, not the mandatory Tables 3-29 ratings. |
| Errata incorporated | Table 20: Class 150 working pressure at 400 °C corrected to 5.5 bar (record 22-203). Table 36: minimum thickness for an NPS 30 weld-neck corrected to 149.4 mm (record 22-99). | If you hold an earlier print, these two values may be wrong in your copy; the 2025 print carries the corrections. |
| References | The References section and the references in Mandatory Appendix I were updated (records 23-2265 and 21-1888). | Cited editions of related standards changed; check the new reference list when writing specifications. |
标准对 2025 版改动的页边注为“(25)”。记录编号按标准呈现顺序列出，不代表重要程度。