Inconel 825 UnionASTM B564 · MSS SP-83 · Manufacturer, trader & exporter, India
Incoloy 825 · Alloy 825
An Inconel 825 union is a three-piece forged fitting that joins pipes and can be taken apart, made from Inconel 825 to ASTM B564. Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends.
For the full 825 fittings range, see Inconel 825 pipe fittings.
- ASTM B564
- MSS SP-83
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Inconel 825 Union?
- What it is
- A three-piece forged fitting that joins pipes and can be taken apart
- Material
- ASTM B564
- Dimensions
- MSS SP-83
- Grade
- Inconel 825 · UNS N08825
- Best at
- Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas
Inconel 825 Union Specification
| Product | Inconel 825 Union |
|---|---|
| Material standard | ASTM B564 |
| Dimensional standard | MSS SP-83 |
| Sizes | ⅛" – 4" (ASME B16.11) |
| Wall / class | Class 2000 / 3000 / 6000 / 9000 |
| Ends | Socket weld · NPT threaded |
| Testing | PMI (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose an Union
Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends.
- Three pieces: nut, male and female ends
- Threaded or socket weld
- Class 3000 / 6000
More on choosing: Union guide.
Inconel 825 Union: Why 825 for unions
Unions let a small-bore line be disconnected for maintenance without cutting. Made to MSS SP-83 in threaded or socket-weld ends. In Inconel 825, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Nickel-alloy fittings match nickel-alloy pipe in aggressive media. Inconel 825 is picked for sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas. |
|---|---|
| Typical service | Sulphuric & phosphoric acid plants — Tank linings, agitators, heat-exchanger baffles in fertiliser and acid production. |
| Welding to carbon steel | A nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel |
| Matching filler | ERNiFeCr-1 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 825 Union Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Iron | As specified |
| Chromium | As specified |
| Molybdenum | As specified |
| Copper | As specified |
| Titanium | As specified |
| Carbon | As specified |
| Manganese | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B424 / B423 / B564 for UNS N08825.
Inconel 825 Union Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM B424 / B423 / B564 for UNS N08825 — Annealed.
Full chemistry, properties and equivalents are on the Inconel 825 grade page.
Standards on this page
Other Inconel 825 pipe fittings
Inconel 825 Union — questions buyers ask
Can unions be used in high-pressure lines?
Class 3000 and 6000 unions are rated for high pressure on small bores, but many codes limit their use in hazardous service.
Can Inconel 825 unions be welded to carbon steel?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel.
Which standard covers Inconel 825 unions?
The material is ASTM B564; dimensions follow MSS SP-83. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 825 union?
The alloy price, the size and schedule or class, quantity, and the testing and documents required. Send your list and we quote the same working day.
Can Inconel 825 unions be supplied to NACE MR0175?
Inconel 825 (UNS N08825) can be supplied for sour service when the PO specifies NACE MR0175 / ISO 15156; acceptability depends on the material condition, hardness and the environmental limits in that standard, which the purchaser must confirm for the application.
What documents do you supply?
EN 10204 3.1 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026