Inconel 825 CapASTM B366 · ASME B16.9 · Manufacturer, trader & exporter, India
Incoloy 825 · Alloy 825
An Inconel 825 cap is a fitting that closes the end of a pipe, made from Inconel 825 to ASTM B366 WPNICMC (buttweld) · ASTM B564 (forged). Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points.
For the full 825 fittings range, see Inconel 825 pipe fittings.
- ASTM B366
- ASME B16.9
- 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 Cap?
- What it is
- A fitting that closes the end of a pipe
- Material
- ASTM B366 WPNICMC (buttweld) · ASTM B564 (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- Inconel 825 · UNS N08825
- Best at
- Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas
Inconel 825 Cap Specification
| Product | Inconel 825 Cap |
|---|---|
| Material standard | ASTM B366 WPNICMC (buttweld) · ASTM B564 (forged) |
| Dimensional standard | ASME B16.9 · B16.11 |
| Sizes | Buttweld ½" – 48" · forged ⅛" – 4" |
| Wall / class | Schedule to match pipe · Class 3000 / 6000 (forged) |
| Ends | Bevelled to ASME B16.25 |
| 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 a Cap
Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points.
- Buttweld dished caps
- Threaded and socket-weld caps
- Wall to match the pipe
More on choosing: Cap guide.
Inconel 825 Cap: Why 825 for caps
Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points. 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 Cap 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 Cap 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.
Other Inconel 825 pipe fittings
Inconel 825 Cap dimensions — ASME B16.9
Values in mm, the same for every material; the wall thickness matches the pipe schedule.
| NPS | OD | Cap length E |
|---|---|---|
| ½" | 21.3 | 25 |
| ¾" | 26.7 | 25 |
| 1" | 33.4 | 38 |
| 1½" | 48.3 | 38 |
| 2" | 60.3 | 38 |
| 3" | 88.9 | 51 |
| 4" | 114.3 | 64 |
| 6" | 168.3 | 89 |
| 8" | 219.1 | 102 |
| 10" | 273.1 | 127 |
| 12" | 323.9 | 152 |
| 16" | 406.4 | 178 |
| 20" | 508.0 | 229 |
| 24" | 610.0 | 267 |
Full chart: ASME B16.9 fitting dimensions.
Inconel 825 Cap — questions buyers ask
Can a cap take full line pressure?
Yes — a buttweld cap of matching schedule is rated like the pipe it closes.
Can Inconel 825 caps 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 caps?
The material is ASTM B366 WPNICMC (buttweld) · ASTM B564 (forged); dimensions follow ASME B16.9 · B16.11. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 825 cap?
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 caps 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