Material selection
Alloy 20 Flanges
Alloy 20 flange enquiries should identify UNS N08020 and the applicable product specification, with corrosion suitability reviewed for the actual process.
Identify the product specification
UNS N08020 identifies the alloy composition family, not a finished flange dimension or inspection package. State the applicable forging or other product specification, required condition and flange standard. Avoid treating a commercial alloy name as a complete purchase description.
Acid-service conditions
Alloy 20 may be evaluated for acid-handling applications, but acid type, concentration, contaminants and temperature are essential to that evaluation. Do not infer universal acid resistance. Include normal operation, cleaning and credible upset conditions in the service information.
Joint compatibility
Review the mating pipe, weld procedure, gasket and fasteners alongside the alloy selection. Pressure-temperature suitability must be established under the project design basis. Specify the material documentation and any supplementary corrosion testing with defined acceptance criteria.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Material designations and distinctions
Reference designations for Alloy 20 Flanges. These are not an availability list or an equivalence table. A trade name, UNS number and ASTM product specification have different roles.
| Parameter / designation | Technical information | Selection requirement |
|---|---|---|
| Alloy 20 / UNS N08020 | Defined nickel-iron-chromium alloy; not a generic stainless grade | Confirm the product specification, grade/condition, design suitability and required material records. |
Compare related options
Compare Alloy 20 Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| Hastelloy Flanges | Hastelloy flanges require an exact alloy designation and process-chemistry review. A family name is not a specification for all corrosive fluids. | Exact alloy or UNS and flange material specification |
| Incoloy Flanges | Incoloy flange enquiries cover defined nickel-iron-chromium alloys. Identify the grade and required condition rather than substituting a similarly named Inconel alloy. | Full alloy variant and product specification |
| Stainless Steel Flanges | Specify stainless steel flanges by grade, product specification and service conditions, not by a bright surface finish or the general name stainless steel. | Material specification, grade and any low-carbon or stabilised variant |
Inspection, documents and delivery
Define acceptance requirements for Alloy 20 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 | The selected flange form, bore, thickness, bolt pattern and mating geometry. | 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 Alloy 20
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Identity | UNS N08020, product specification and condition |
| Process | Acid composition, concentration and contaminants |
| Joint | Weld procedure, mating material and gasket |
| Acceptance | Material records and required service-specific tests |
Continue the specification