Monel K500 Long Weld Neck FlangeASTM B865 · ASME B16.5 (flange end) · Manufacturer, stockist & exporter, India
Alloy K-500 · UNS N05500 · LWN
A Monel K500 long weld neck flange is a weld neck flange with an extended straight neck, used as a vessel nozzle, made from Monel K500 to ASTM B865. Long weld neck flanges are used as nozzles on vessels and columns, with the neck welded into the shell. Standard neck lengths are 9" and 12", or made to drawing.
- ASTM B865
- ASME B16.5 (flange end)
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is a Monel K500 Long Weld Neck Flange?
- What it is
- A weld neck flange with an extended straight neck, used as a vessel nozzle
- Material
- ASTM B865
- Dimensions
- ASME B16.5 (flange end)
- Grade
- Monel K500 · UNS N05500
- Best at
- High-strength pump shafts, bolting and springs in seawater
Monel K500 Long Weld Neck Flange Specification
| Product | Monel K500 Long Weld Neck Flange |
|---|---|
| Material standard | ASTM B865 |
| Dimensional standard | ASME B16.5 (flange end) |
| 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 Long Weld Neck Flange
Long weld neck flanges are used as nozzles on vessels and columns, with the neck welded into the shell. Standard neck lengths are 9" and 12", or made to drawing.
- Heavy-barrel and equal-barrel designs
- Neck length 9" / 12" or to drawing
- Often machined from solid bar in alloys
More on choosing: Long weld neck flange guide.
Monel K500 Long Weld Neck Flange: Why K500 for long weld neck flanges
Long weld neck flanges are used as nozzles on vessels and columns, with the neck welded into the shell. Standard neck lengths are 9" and 12", or made to drawing. In Monel K500, 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. Monel K500 is picked for high-strength pump shafts, bolting and springs in seawater. |
|---|---|
| Typical service | Marine — Propeller and pump shafts. |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Monel K500 from ASTM B865, 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 | ERNiCu-7 (non-ageing) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Monel K500 Long Weld Neck Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+Co) | 63.0 min |
| Copper | 27.0 – 33.0 |
| Aluminium | 2.30 – 3.15 |
| Titanium | 0.35 – 0.85 |
| Iron | 2.0 max |
| Manganese | 1.5 max |
| Carbon | 0.25 max |
| Silicon | 0.5 max |
Monel K500 Long Weld Neck Flange Mechanical Properties
| Age-hardened bar | Value |
|---|---|
| Tensile strength | 965 MPa · 140 ksi |
| Yield strength 0.2% | 690 MPa · 100 ksi |
| Elongation | 20% |
Full chemistry, properties and equivalents are on the Monel K500 grade page.
Other Monel K500 flanges
Monel K500 Long Weld Neck Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiMonel K500 Long Weld Neck 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.
Monel K500 Long Weld Neck Flange — questions buyers ask
What is the difference between equal-barrel and heavy-barrel LWN?
Equal-barrel has a uniform neck; heavy-barrel has a thicker neck for extra reinforcement at the vessel wall.
Can Monel K500 long weld neck 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 Monel K500 long weld neck flanges?
The material is ASTM B865; dimensions follow ASME B16.5 (flange end). Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Monel K500 long weld neck 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 Monel K500 long weld neck flanges to NACE MR0175?
Yes. Monel K500 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