Facing reference
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.
Raised gasket seating
The raised portion concentrates the gasket seating within the designated sealing area. Its height and dimensions depend on the applicable flange standard and designation. Do not infer these dimensions from a photograph or assume one raised-face geometry applies across every class and standard.
Gasket and surface finish
Specify the gasket type, dimensions and required facing finish. Surface texture must be compatible with the selected gasket and the assembly requirements. A visibly machined surface is not evidence that its roughness, serration or condition meets the project specification.
Mating compatibility
Confirm both flange faces and the approved joint assembly. Mixing raised and flat faces can create an unsuitable loading arrangement, particularly where flange materials have different stiffness or brittleness. The designer must approve the complete gasket, flange and bolting combination.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Mating face and gasket requirements
For Raised Face (RF) Flanges, face geometry, gasket selection and assembly loading must be reviewed together. Confirm the complete mating pair before ordering.
| Parameter / designation | Technical information | Selection requirement |
|---|---|---|
| Raised seating area | Identify raised-face diameter, height and required finish under the governing standard. | The raised face is a sealing feature, not the flange hub. |
| Gasket dimensions | Specify a gasket designed for the selected RF joint and service. | Gasket contact must remain within the intended seating geometry. |
| Mating face | Confirm compatible face geometry on both sides. | Mixed RF/FF joints require a design review, especially with brittle flange materials. |
| Finish and defects | State the required finish and inspection limits. | Do not accept a polished or serrated appearance as proof of the specified finish. |
Compare related options
Compare Raised Face (RF) Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| 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 Raised Face (RF) 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 | Seating diameter, face profile, recess/projection and mating clearances. | 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 | Gasket dimensions/material, mating flange and bolting procedure. | 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 Raised Face (RF)
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Facing | RF dimensions under the exact flange standard and designation |
| Gasket | Type, material, inside/outside dimensions and thickness |
| Finish | Required surface texture and acceptance criteria |
| Assembly | Mating face, flange material and bolting procedure |
Continue the specification