ASME B16.5 defines pipe-flange dimensions and ratings for Classes 150, 300, 400, 600, 900 and 1500 at NPS 1/2 to 24, and Class 2500 at NPS 1/2 to 12. This RFQ page covers weld neck, slip-on, blind, socket weld, threaded and lap joint requests; the exact type, size, class and facing must be checked against the applicable table.
BLD reviews these flange types against the applicable B16.5 table, with RF, FF or RTJ facing checked for the exact line item before quotation. Material requests may specify ASTM A105/A105N, A350 LF2, A182 F304/F316/F321/F347, duplex or project alloys; feasibility and certificate scope depend on the purchase specification. Above NPS 24, an RFQ may use B16.47 or a project drawing, with the governing standard confirmed first. ASME B16.5 tabulates Class 2500 through NPS 12; above NPS 12 we forge Class 2500 flanges to your drawing and design calculation.
Two details are worth stating on the enquiry that are often left out: the bore or pipe schedule, which B16.5 does not fix for weld neck flanges, and the standard edition your specification is written against. Verification is a dimensional check against the tables plus marking, MTC 3.1, PMI on alloy grades and NDT where the project specification adds it.
Product family: Flanges
ASME B16.5 flange requests are reviewed by NPS, class, facing, material, bore, quantity, inspection and documentation requirements.
| Scope and rating | |
|---|---|
| ASME scope | ASME B16.5 pipe flanges: Classes 150, 300, 400, 600, 900 and 1500 at NPS 1/2 to 24; Class 2500 at NPS 1/2 to 12. Above NPS 12 we forge Class 2500 flanges to your drawing and design calculation. Check type, facing and feasibility against the exact table and RFQ. |
| Standards and materials | |
| Standards / drawings |
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| Material grades |
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| Geometry, tolerance and inspection | |
| Product types | Weld neck, slip-on, blind, socket weld, threaded, lap joint and special drawing-based ASME line items. |
| Critical dimensions | NPS, Class, flange type, RF/RTJ/FF facing, bore or schedule, drilling and standard edition. |
| Inspection depth | ASME dimension check, marking, MTC 3.1, PMI for alloy grades, NDT when project specification requires it. |
| Reviewed before quotation |
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| Buying logic | |
| Best-fit RFQ | Best for ASME B16.5 NPS 1/2 to 24 line items where type, class and facing are already specified. |
| Buyer application | International EPC flange packages, distributor stock, pressure piping and valve connections. |
Your standard, drawing revision and project specification govern.
Direct Technical Download
Download a one-page buyer reference with selected Class 150 NPS, flange outside diameter, minimum flange thickness and hub diameter data. The dimensions are copied from a public ASME B16.5 dimension reference; no estimated or invented values are used.
This link opens directly without a form gate so buyers can check line items before sending a formal RFQ.
Also known as
We confirm each step against your drawing or standard before we quote.
Material grade, heat number, certificate basis and substitution limits are checked against the ASME B16.5 Flanges drawing or standard before procurement is released.
The forging route is selected around flange type, section thickness, bore allowance, hub or neck geometry and pressure-service requirements.
Heat treatment is planned with the required record package, mechanical testing basis and impact-test condition where low-temperature or alloy service applies.
Rough machining opens reference faces, bore, hub, neck or sealing-face stock needed to control allowance before final flange machining.
Final machining controls facing, bore, bolt pattern, groove, sealing surface and flange-table or drawing tolerances before dimensional inspection is issued.
Inspection covers dimensional report, MTC 3.1, PMI and required UT, MT or PT records before the release documents are matched to the purchase order.
Marking, packing and export documents are prepared by PO line item so the ASME B16.5 Flanges shipment can clear customs and be identified at site receiving.
List document requirements in the first RFQ; they affect price and schedule.
Above NPS 24 an RFQ may use ASME B16.47, which covers NPS 26 to 60, or a project drawing, so we confirm the governing standard first. Within B16.5, Classes 150 to 1500 run to NPS 24 and Class 2500 to NPS 12. Class 2500 above NPS 12 we forge to your drawing.
The bore or pipe schedule, which B16.5 does not fix for weld neck flanges, and the standard edition your specification is written against. Please state both on the enquiry.
Weld neck, slip-on, blind, socket weld, threaded and lap joint flanges, plus special drawing-based ASME line items. Each is checked against the applicable B16.5 table for type, size, class and RF, FF or RTJ facing.
By a dimensional check against the B16.5 tables plus marking, MTC 3.1, PMI on alloy grades and NDT where the project specification adds it.
Email quote@bldforgedirect.com with standard, drawing, material, quantity and inspection requirements.