Material 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.
Different alloys, different requirements
Designations such as C-276, C-22 and B-3 refer to different nickel-alloy compositions. They are not interchangeable on the strength of the Hastelloy name. Identify the exact alloy or UNS designation and the product specification required for the flange.
Define the corrosion environment
Provide chemical composition, concentration, contaminants, temperature and cleaning or upset conditions. Oxidising and reducing environments may drive different selection decisions. Localised corrosion and welded regions need to be included in the material review rather than assessed only from general corrosion rates.
Manufacturing and traceability
State the required material condition, weld preparation and inspection scope. Surface cleanliness and contamination control may be important to fabrication. Maintain traceability between the flange, material certificate and any supplementary test records requested by the project.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Material designations and distinctions
Reference designations for Hastelloy 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 |
|---|---|---|
| C-276 / UNS N10276 | Nickel-molybdenum-chromium alloy | Confirm the product specification, grade/condition, design suitability and required material records. |
| C-22 / UNS N06022 | Distinct alloy; substitution requires design approval | Confirm the product specification, grade/condition, design suitability and required material records. |
Compare related options
Compare Hastelloy Flanges with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| Inconel Flanges | Specify Inconel flanges by alloy number and product specification. The nickel-chromium alloy family spans different corrosion, temperature and strength requirements. | Alloy number or UNS and product specification |
| Alloy 20 Flanges | Alloy 20 flange enquiries should identify UNS N08020 and the applicable product specification, with corrosion suitability reviewed for the actual process. | UNS N08020, product specification and condition |
| Flange Material Selection | Choose a flange material from the service and fabrication requirements, then define the exact grade and product specification. A photograph or broad alloy family cannot establish suitability. | Fluid chemistry, temperatures, pressure and external exposure |
Inspection, documents and delivery
Define acceptance requirements for Hastelloy 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 Hastelloy
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Alloy | Exact alloy or UNS and flange material specification |
| Chemistry | Concentration, contaminants and oxidation conditions |
| Operation | Design temperatures, cleaning and upset conditions |
| Documents | Traceability, heat treatment and supplementary testing |
Continue the specification