Incoloy 800 / 800H / 800HT Blind FlangeASTM B564 · ASME B16.5 · Manufacturer, stockist & exporter, India
Alloy 800 · UNS N08800 / N08810 / N08811 · BLRF
An Incoloy 800 / 800H / 800HT blind flange is a solid disc that closes the end of a pipe, valve or vessel nozzle, made from Incoloy 800 / 800H / 800HT to ASTM B564. Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class.
- ASTM B564
- ASME B16.5
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Incoloy 800 / 800H / 800HT Blind Flange?
- What it is
- A solid disc that closes the end of a pipe, valve or vessel nozzle
- Material
- ASTM B564
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Grade
- Incoloy 800 / 800H / 800HT · UNS N08800
- Best at
- Furnaces, petrochemical heaters and high-temperature piping
Incoloy 800 / 800H / 800HT Blind Flange Specification
| Product | Incoloy 800 / 800H / 800HT Blind Flange |
|---|---|
| Material standard | ASTM B564 |
| Dimensional standard | ASME B16.5 · B16.47 · EN 1092-1 |
| Sizes | ½" – 24" (ASME B16.5) · 26" – 60" (ASME B16.47) |
| Pressure class | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Blind Flange
Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class.
- No bore; thickness set by the pressure class
- Can be drilled and tapped for an instrument connection
- Often cut from plate in large sizes or special alloys
More on choosing: Blind flange guide.
Incoloy 800 / 800H / 800HT Blind Flange: Why 800 for blind flanges
Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class. In Incoloy 800 / 800H / 800HT, 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 flanges are used where acids, chlorides or heat defeat stainless. Incoloy 800 / 800H / 800HT is picked for furnaces, petrochemical heaters and high-temperature piping. |
|---|---|
| Typical service | Petrochemical — Steam-methane reformer and ethylene furnace piping. |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Incoloy 800 / 800H / 800HT from ASTM B408, as the project specifies |
| 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 | ERNiCr-3 (AWS A5.14) |
Incoloy 800 / 800H / 800HT Blind Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 30.0 – 35.0 |
| Chromium | 19.0 – 23.0 |
| Iron | 39.5 min |
| Carbon | 0.10 max (800) · 0.05 – 0.10 (800H) |
| Aluminium | 0.15 – 0.60 |
| Titanium | 0.15 – 0.60 |
| Copper | 0.75 max |
| Manganese | 1.5 max |
Incoloy 800 / 800H / 800HT Blind Flange Mechanical Properties
| Annealed plate | Value |
|---|---|
| Tensile strength | 520 MPa · 75 ksi (800) · 450 MPa · 65 ksi (800H) |
| Yield strength 0.2% | 205 MPa · 30 ksi (800) · 170 MPa · 25 ksi (800H) |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the Incoloy 800 / 800H / 800HT grade page.
Other Incoloy 800 / 800H / 800HT flanges
Incoloy 800 / 800H / 800HT Blind Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiIncoloy 800 / 800H / 800HT Blind Flange dimensions — ASME B16.5 Class 150 & 300
Outside diameter, thickness and bolting are set by size and class. Values in mm; thickness excludes the 1.6 mm raised face.
| NPS | Cl 150 OD | Cl 150 thickness | Cl 150 bolt circle | Cl 150 bolts | Cl 300 OD | Cl 300 thickness | Cl 300 bolt circle | Cl 300 bolts |
|---|---|---|---|---|---|---|---|---|
| ½" | 90 | 9.6 | 60.3 | 4 × ½" | 95 | 12.7 | 66.7 | 4 × ½" |
| 1" | 110 | 12.7 | 79.4 | 4 × ½" | 125 | 15.9 | 88.9 | 4 × ⅝" |
| 1½" | 125 | 15.9 | 98.4 | 4 × ½" | 155 | 19.1 | 114.3 | 4 × ¾" |
| 2" | 150 | 17.5 | 120.7 | 4 × ⅝" | 165 | 20.7 | 127.0 | 8 × ⅝" |
| 3" | 190 | 22.3 | 152.4 | 4 × ⅝" | 210 | 27.0 | 168.3 | 8 × ¾" |
| 4" | 230 | 22.3 | 190.5 | 8 × ⅝" | 255 | 30.2 | 200.0 | 8 × ¾" |
| 6" | 280 | 23.9 | 241.3 | 8 × ¾" | 320 | 35.0 | 269.9 | 12 × ¾" |
| 8" | 345 | 27.0 | 298.5 | 8 × ¾" | 380 | 39.7 | 330.2 | 12 × ⅞" |
| 10" | 405 | 28.6 | 362.0 | 12 × ⅞" | 445 | 46.1 | 387.4 | 16 × 1" |
| 12" | 485 | 30.2 | 431.8 | 12 × ⅞" | 520 | 49.3 | 450.8 | 16 × 1⅛" |
Full chart: ASME B16.5 flange dimensions.
Incoloy 800 / 800H / 800HT Blind Flange — questions buyers ask
Can a blind flange be cut from plate?
For many sizes and classes, yes — especially in nickel alloys where forgings are expensive. The material then follows the plate standard and must be approved by the purchaser.
Can Incoloy 800 / 800H / 800HT blind flanges 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 Incoloy 800 / 800H / 800HT blind flanges?
The material is ASTM B564; dimensions follow ASME B16.5 · B16.47 · EN 1092-1. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Incoloy 800 / 800H / 800HT blind flange?
The alloy price, the size and pressure class, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026