Raised Face (RF)
A raised face provides a gasket seating surface inside the bolt circle. Specify the face dimensions, finish and gasket as a coordinated joint requirement.
Mating surface guide
Flange Facings & Finishes
Flange faces, gaskets and surface finishes form a single joint specification. Confirm the complete mating arrangement.
These references help define an enquiry; they are not a declaration of stock, certification or suitability for a particular service.
Browse flange typesView guide
Flat Face (FF)
A flat face has no raised gasket seating step. Confirm the gasket coverage, mating flange material and joint loading rather than identifying it only by appearance.
Ring Type Joint (RTJ)
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.
Tongue and Groove
A tongue-and-groove joint pairs a projecting tongue with a matching groove. The two faces and the confined gasket dimensions must be specified together.
Male and Female
A projecting male face mates with a recessed female face. Specify the full seating geometry and gasket requirements rather than substituting tongue-and-groove terminology.
Lap Joint Assembly
In a lap-joint assembly, the stub end provides the gasket seating surface. The separate backing flange transfers bolt load and can rotate for alignment before tightening.
From specification to enquiry
A connection starts with the right details.
Send your material, size, rating, facing and quantity. Include a drawing reference for non-standard requirements.
Dimensions and connection data
Define Flange Facings & Finishes as part of the complete joint. These fields identify required engineering data; they are not universal dimensions or a declaration of available sizes.
| Parameter / designation | Technical information | Selection requirement |
|---|---|---|
| Nominal size and bore | State the nominal connection size separately from the actual bore or pipe outside diameter. | A matching size label does not establish matching internal geometry. |
| Outside diameter and thickness | Identify the finished flange diameter, minimum thickness and any hub or collar projection. | Include the drawing datum and units for replacement measurements. |
| Bolt circle and holes | Record pitch-circle diameter, hole quantity, hole diameter and any special orientation. | Check against the mating flange; do not infer a bolt pattern from pressure class alone. |
| Gasket-contact surfaces | Specify face form, seating dimensions and surface finish on the assembled joint. | Include gasket designation; a visually similar surface is not evidence of compatibility. |
| Pipe-side interface | Identify weld preparation, socket, thread, collar or other attachment geometry as applicable. | Provide pipe schedule/wall thickness and the connection-specific standard. |
| Design conditions | State design pressure, minimum/maximum temperature, fluid and mechanical loads. | Pressure class is not a pressure value in bar or psi. Use the material-specific rating basis. |
Compare related options
Compare Flange Facings & Finishes with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| Raised Face (RF) Flanges | A raised face provides a gasket seating surface inside the bolt circle. Specify the face dimensions, finish and gasket as a coordinated joint requirement. | RF dimensions under the exact flange standard and designation |
| Flat Face (FF) Flanges | A flat face has no raised gasket seating step. Confirm the gasket coverage, mating flange material and joint loading rather than identifying it only by appearance. | Type, construction, material and applicable standard |
| 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 |
| Tongue and Groove Flanges | A tongue-and-groove joint pairs a projecting tongue with a matching groove. The two faces and the confined gasket dimensions must be specified together. | Tongue side, groove side or complete mating set |
| Male and Female Flanges | A projecting male face mates with a recessed female face. Specify the full seating geometry and gasket requirements rather than substituting tongue-and-groove terminology. | Male, female or matched pair |
| Lap Joint Assembly | In a lap-joint assembly, the stub end provides the gasket seating surface. The separate backing flange transfers bolt load and can rotate for alignment before tightening. | Backing flange and stub-end designations separately |
Inspection, documents and delivery
Define acceptance requirements for Flange Facings & Finishes 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. |