Inconel 718 Ring Type Joint FlangeASTM B637 · ASME B16.5 · Manufacturer, stockist & exporter, India
Alloy 718 · UNS N07718 · RTJ
An Inconel 718 ring type joint flange is a flange with a machined groove for a metal ring gasket, made from Inconel 718 to ASTM B637. RTJ flanges are used for high pressure and temperature — typically Class 600 and above, and on wellhead and API equipment. The metal ring deforms into the groove to seal.
- ASTM B637
- 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 Inconel 718 Ring Type Joint Flange?
- What it is
- A flange with a machined groove for a metal ring gasket
- Material
- ASTM B637
- Dimensions
- ASME B16.5 · ASME B16.20
- Grade
- Inconel 718 · UNS N07718
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Ring Type Joint Flange Specification
| Product | Inconel 718 Ring Type Joint Flange |
|---|---|
| Material standard | ASTM B637 |
| Dimensional standard | ASME B16.5 · ASME B16.20 |
| 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 Ring Type Joint Flange
RTJ flanges are used for high pressure and temperature — typically Class 600 and above, and on wellhead and API equipment. The metal ring deforms into the groove to seal.
- Groove to ASME B16.20 ring numbers
- Ring gasket softer than the groove material
- Groove hardness checked on order
More on choosing: Ring type joint flange guide.
Inconel 718 Ring Type Joint Flange: Why 718 for ring type joint flanges
RTJ flanges are used for high pressure and temperature — typically Class 600 and above, and on wellhead and API equipment. The metal ring deforms into the groove to seal. In Inconel 718, 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. Inconel 718 is picked for very high strength at temperatures up to about 650 °C. |
|---|---|
| Typical service | Oil & gas — Wellhead parts, hangers and high-strength bolting. |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Inconel 718 from ASTM B637, 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 | ERNiFeCr-2 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 718 Ring Type Joint Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+Co) | 50.0 – 55.0 |
| Chromium | 17.0 – 21.0 |
| Niobium + Tantalum | 4.75 – 5.50 |
| Molybdenum | 2.80 – 3.30 |
| Titanium | 0.65 – 1.15 |
| Aluminium | 0.20 – 0.80 |
| Carbon | 0.08 max |
| Iron | Balance |
Inconel 718 Ring Type Joint Flange Mechanical Properties
| Solution-treated and aged | Value |
|---|---|
| Tensile strength | 1275 MPa · 185 ksi |
| Yield strength 0.2% | 1034 MPa · 150 ksi |
| Elongation | 12% |
Full chemistry, properties and equivalents are on the Inconel 718 grade page.
Other Inconel 718 flanges
Inconel 718 Ring Type Joint Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiInconel 718 Ring Type Joint 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.
Inconel 718 Ring Type Joint Flange — questions buyers ask
Which ring gasket goes with an RTJ flange?
Oval or octagonal rings to ASME B16.20, in a material softer than the flange groove.
Can Inconel 718 ring type joint 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 Inconel 718 ring type joint flanges?
The material is ASTM B637; dimensions follow ASME B16.5 · ASME B16.20. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 718 ring type joint 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.
Can you supply Inconel 718 ring type joint flanges to NACE MR0175?
Yes. Inconel 718 is listed in NACE MR0175 / ISO 15156-3 within its limits; state NACE compliance on the order and it is confirmed on the certificate.
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