Standard reference
ASME B16.5 Flanges
An ASME B16.5 enquiry identifies the flange type, nominal size, class, material and facing under the specified edition. The standard name alone does not define a complete joint.
Pipe-flange scope
ASME B16.5 addresses pipe flanges and flanged fittings within its stated scope. Confirm that the requested size, type, material and class are covered by the contract edition. Large-diameter flanges, orifice flanges and operational line blanks have distinct references and should not inherit a generic B16.5 description.
Dimensions and pressure-temperature rating
Dimensional compatibility and pressure-temperature suitability are separate checks. Match the bolt pattern, bore and facing to the mating component, then verify the applicable rating using the material and design temperature. Class is a designation, not an allowable pressure in psi at every temperature.
Enquiry and inspection
Specify the bore or pipe schedule where relevant, end preparation, surface finish and documentation. Identify any non-standard drilling, counterboring or other modification explicitly. Inspection requirements beyond the standard should be stated as project requirements with defined acceptance criteria.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Standard scope and ordering designation
Use ASME B16.5 only within its applicable scope. Obtain numerical dimensions and rating tables from the governing standard and the approved project documentation.
| Parameter / designation | Technical information | Selection requirement |
|---|---|---|
| Standard and edition | ASME B16.5 | Record the exact edition and applicable type/series in the purchase description. |
| Scope | An ASME B16.5 enquiry identifies the flange type, nominal size, class, material and facing under the specified edition. The standard name alone does not define a complete joint. | Check size, material and component scope before applying any table. |
| Dimensional designation | Nominal size, series/type, rating designation and dimensional units. | Matching nominal size does not prove matching bolt circle, thickness or facing. |
| Material-dependent rating | Material group, design temperature and any standard-specific rating rules. | Do not read a class number as a direct pressure limit or transfer ratings between materials. |
| Related requirements | Gaskets, fasteners, attachment welds and the project piping/equipment code. | The flange standard does not replace complete assembly design or installation requirements. |
| Legacy or alternate designations | Existing drawing number, original standard and proposed replacement designation. | Verify dimensions and suitability rather than assuming historical names are equivalent. |
Compare related options
Compare ASME B16.5 Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| ASME B16.47 Flanges | ASME B16.47 covers large-diameter steel flange requirements within its defined scope. Every enquiry must distinguish Series A from Series B. | Explicit Series A or Series B designation |
| ASME B16.36 Flanges | ASME B16.36 is the flange reference for orifice-flange arrangements within its scope. It does not replace the design of the differential-pressure metering system. | B16.36 edition, configuration, size, class and material |
| Flange Pressure Ratings | A flange class, PN designation or table is not a universal allowable pressure. The design must use the specified standard, material and temperature together. | Exact edition and flange/rating designation |
Inspection, documents and delivery
Define acceptance requirements for ASME B16.5 Flanges in the purchase order. Required examinations and documents depend on the material, design and project specification.
| Review stage | Information to confirm | Order requirement |
|---|---|---|
| Material identity and traceability | Specification, grade, heat/lot identification and the required material certificate. | Agree documentation and marking before manufacture; visual appearance cannot verify alloy identity. |
| Dimensional verification | Critical dimensions from the selected standard or controlled drawing. | Identify inspection points, tolerances, units and drawing revision. |
| Surface and end condition | Gasket-contact surface, attachment end, edges and any coating exclusions. | State finish and visual acceptance criteria; agree protection of machined surfaces. |
| Supplementary examinations | Any specified PMI, NDE, hardness, impact, corrosion or other tests. | Define the method, sampling and acceptance criteria; tests are not automatically included. |
| Assembly compatibility | Adjoining components, weld or mechanical interface and project service conditions. | Design approval and correct assembly remain separate from a dimensional inspection report. |
| Packing and order release | Quantity, identification, surface protection, documents and delivery destination. | Agree preservation, packaging and release requirements with the order. |
Enquiry checklist
Details for ASME B16.5
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Designation | ASME B16.5 edition, flange type, NPS and class |
| Material | Complete material specification and grade |
| Interface | Facing, bore, pipe schedule and end preparation |
| Acceptance | Marking, dimensional inspection and documentation |
Continue the specification