Размеры фланцев из легированной стали ASME B16.5 и классы давления
Прямой ответ
ASME B16.5 defines pressure-temperature ratings, размеры, допуски, материалы, marking and testing for pipe flanges and flanged fittings from NPS 1/2 through NPS 24. It includes Classes 150, 300, 400, 600, 900 и 1500 across applicable sizes, with Class 2500 limited to NPS 1/2 through NPS 12.
Key takeaways
- Material specification and dimensional standard must both appear on the order.
- The bore of a weld neck flange must be specified to match the pipe wall.
- Do not scale dimensions from a drawing or substitute B16.47 dimensions for B16.5.
Dimensions controlled by ASME B16.5
Depending on flange type, the standard controls outside diameter, толщина, hub dimensions, bolt-circle diameter, bolt-hole quantity and size, facing geometry and other details. Weld neck flanges additionally require attention to bore and weld-end configuration.
Tolerances matter. A nominal dimension from a catalogue is not a manufacturing inspection plan; use the standard and project drawing for acceptance.
Size and class scope
| Item | ASME B16.5 scope summary |
|---|---|
| Номинальный размер | НПС 1/2 through NPS 24 |
| Classes | 150, 300, 400, 600, 900 и 1500 within applicable size ranges |
| Сорт 2500 | НПС 1/2 through NPS 12 |
| Материалы | Cast or forged flanges; specified blind/reducing configurations may use permitted plate material |
| Joint details | Includes requirements and recommendations for bolting, gaskets and flange joints |
Material and dimensions are separate decisions
«ASTM A182 F22” defines a material grade; «ASME B16.5 Сорт 600 WNRF” defines a dimensional and rating configuration. Neither statement alone creates a complete flange specification.
Add NPS, лицом к лицу, pipe schedule/bore, обработка поверхности, standard edition and inspection documents. For RTJ flanges, include the correct ring groove designation.
Dimensional inspection before shipment
A useful report records critical dimensions against specified nominal values and tolerances. Inspection typically covers OD, толщина, hub, бурить, болт круг, holes, facing and overall height. Calibrated equipment and drawing revision should be identified.
For replacement flanges, the buyer should provide an approved field measurement or equipment drawing. Corroded samples can conceal the original facing height or edge profile, so reverse engineering from a worn component requires engineering judgement and should not be treated as a standard catalogue order.
Protect sealing faces and weld ends after final inspection so packing and transport do not invalidate the accepted condition.
Часто задаваемые вопросы
Does ASME B16.5 cover NPS 30 фланцы?
Нет. ASME B16.47 addresses large-diameter steel flanges from NPS 26 through NPS 60.
Is the bore fixed by pressure class?
Not by class alone. Weld neck bore selection must account for the specified pipe outside diameter and wall thickness.
Are Class 300 и класс 600 bolt patterns interchangeable?
Do not assume so. Use the exact dimensional table for the size, class and facing.
Primary standards referenced
Always verify the edition specified by the purchase order and obtain the complete controlled standard for design and acceptance.
Request an alloy steel flange quotation
Send the material grade, стандартный, НПС, класс давления, тип фланца, лицом к лицу, pipe schedule, требования к количеству и проверке. SASA FLANGE will review the technical description before quotation.
