Standard reference
API 6A Flanges
API 6A flange connections belong to wellhead and tree equipment requirements. They are not general pipe flanges or a modern name for historical API 605 flanges.
Equipment connection identity
Use the equipment specification to identify the exact connection type, size and pressure designation. Confirm the applicable API 6A edition and all required equipment or product levels and classes. The connection cannot be selected from a generic flange-size list.
Seal and mating geometry
The mating connection and specified sealing system must be coordinated as an assembly. Ring or groove designations from another flange system must not be substituted by appearance. Obtain the equipment drawing, gasket requirements and relevant acceptance criteria.
Scope and certification
A reference to API 6A on an enquiry is not evidence of a supplier licence, certification or product compliance. Define the exact manufacturing, testing, documentation and marking requirements for the order. Confirm the offered scope before making any approval or monogram claim.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Standard scope and ordering designation
Use API 6A 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 | API 6A | Record the exact edition and applicable type/series in the purchase description. |
| Scope | API 6A flange connections belong to wellhead and tree equipment requirements. They are not general pipe flanges or a modern name for historical API 605 flanges. | 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 API 6A Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| Ring Type Joint (RTJ) Flanges | An RTJ face uses a machined groove and a matching metal ring gasket. Ring and groove designations must be specified as a system, not chosen by nominal pipe size alone. | Flange standard, connection designation and groove details |
| ASME B16.47 Series B Flanges | Series B is a separate large-diameter flange series within ASME B16.47. Confirm its complete interface before ordering replacements or mating equipment. | ASME B16.47 edition and Series B |
Inspection, documents and delivery
Define acceptance requirements for API 6A 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 API 6A
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Connection | Equipment drawing, exact type, size and pressure designation |
| Requirements | Edition and all specified API 6A levels/classes |
| Sealing | Mating geometry and required gasket/ring designation |
| Records | Testing, traceability, marking and certification requirements |
Continue the specification