Standard reference
UNI Flanges
UNI identifies a standards system, not one universal flange design. State the full UNI number, edition and flange designation for a useful enquiry.
Recover the exact reference
Identify the flange type, nominal size, pressure designation and material alongside the complete UNI standard number. A short legacy callout may leave the facing or manufacturing route unresolved. Original equipment drawings are particularly useful for replacement enquiries.
Current and legacy standards
Determine whether the requirement is an original UNI specification or a specified European replacement. Compare scope, dimensions, materials and facing requirements before substitution. Keep the contractual standard and any approved deviation visible on the enquiry.
Coordinate the joint
Verify the flange-to-pipe connection, mating face, gasket and bolt pattern. Material suitability and pressure-temperature capability require a separate design review. State traceability and inspection requirements so dimensional matching is not mistaken for complete technical compliance.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Standard scope and ordering designation
Use UNI 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 | UNI | Record the exact edition and applicable type/series in the purchase description. |
| Scope | UNI identifies a standards system, not one universal flange design. State the full UNI number, edition and flange designation for a useful enquiry. | 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 UNI Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| EN 1092-1 Flanges | EN 1092-1 flange enquiries use a steel flange type, DN and PN designation together with the exact material and facing requirements. | EN 1092-1 edition, type, DN and PN |
| DIN Flanges | DIN describes a standards system, not one flange specification. A DIN flange enquiry needs the full standard number, edition and dimensional designation. | Full DIN number, edition and status required by the contract |
Inspection, documents and delivery
Define acceptance requirements for UNI 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 UNI
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Document | Full UNI number, edition and legacy/current requirement |
| Designation | Type, nominal size, pressure designation and material |
| Joint | Facing, bore, bolt pattern and mating drawing |
| Approval | Any replacement standard or non-standard deviation |
Continue the specification