Nickel Alloy Butt-weld Fittings

Butt-weld fittings are critical components that achieve piping system connections through butt welding with pipes. Featuring high connection strength, low flow resistance, reliable sealing, and suitability for demanding conditions, they are widely used in petrochemical, offshore engineering, nuclear power energy, pharmaceutical food, and shipbuilding industries. The nickel alloy butt-weld fittings supplied by us are manufactured from high-quality nickel-based alloy seamless pipes or plates through multiple precision processes including pushing/pressing/stamping, solution heat treatment, sizing, machining, and pickling/passivation. Featuring uniform wall thickness, good streamlined shape, dense structure, and excellent corrosion resistance, they are specifically designed for piping systems under high temperature, high pressure, and severe corrosion conditions.

Main Product Types:

1. Butt-weld Elbow: 45°, 90°, 180° direction change
2. Butt-weld Tee: Equal/reducing, branching or merging
3. Butt-weld Cross: Four-way branching
4. Butt-weld Reducer: Concentric/eccentric, diameter change
5. Butt-weld Cap: Closing pipe ends
6. Butt-weld Stub End: Used with lap joint flanges

Supply Range

Nominal Diameter (DN/NPS): DN15 – DN600 (1/2 inch – 24 inches)

Wall Thickness: SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160, XXS

Forming Process: Seamless Pushing (DN≤600), Plate Forming/Welding (DN>600 or non-standard)

End Type: Bevelled End (standard), Plain End optional

Surface Condition: Pickled, Passivated, Polished optional

Dimensional Inspection

1. End OD: Measuring using calipers, tape measures
2. Wall Thickness: Multi-point measurement using ultrasonic thickness gauges
3. Center to End Distance: Measuring using tape measures, templates
4. Elbow Angle: Measuring using angle gauges, templates
5. End Bevel: Inspecting bevel angle, root face dimensions

Appearance Inspection

1. Surface Quality: Visual inspection, no cracks, folds, laps, or other defects
2. Internal/External Surface: Inspecting smoothness, no scratches, pits

Non-Destructive Testing

1. Penetrant Testing (PT): 100% inspection of internal and external surfaces
2. Radiographic Testing (RT): Inspecting weld seams for welded fittings
3. Ultrasonic Thickness Measurement: Verifying minimum wall thickness

Third-Party Inspection Support

We welcome clients to designate international Third-party inspection agencies for pre-shipment inspection, with shipment only after passing inspection.

Which standard governs which property

Nickel alloy pipe systems are governed by two separate families of
standard, and buyers routinely conflate them. The material
is fixed by an ASME Section II specification; the dimensions
are fixed by an ASME B16 series dimensional standard. A fitting can be
perfectly correct on chemistry and still be wrong on centre-to-end.

ASME SB-366 Scope 1.1 states that wrought welding fittings are those
covered by ASME B16.9, ASME B16.11, MSS SP-43, MSS SP-95 and MSS SP-97. That
cross-reference is the authoritative link between the material specification
and the dimensional standard.

Nickel alloy grades supplied against each fitting form

The grades below are those covered by the material specifications we
supply against. Note that not every grade is available in every
form — a grade listed for forgings is not automatically
available as a weld-neck flange, because flange product forms carry their
own material specification.

Verified against ASME BPVC Section II: SB-366 (wrought nickel and nickel
alloy fittings), SB-564 (nickel alloy forgings, scope lists N04400, N06600,
N06625, N10276, N06022, N06200, N08020, N08031), SB-462 (forged nickel alloy
pipe flanges, scope lists N10276, N06022, N06200, N08020, N08031).
Precipitation-hardenable grades such as N07718 (Inconel 718) are
not covered by SB-366 or SB-564; they fall under SB-637.
SA-182 is a low-alloy and stainless steel specification and contains no
nickel alloy grades.

Procurement questions that prevent most fit-up disputes

1. Which specification number is on the purchase order?
   Alloy trade names are ambiguous across suppliers. Inconel 625 can be ordered
   as SB-366 (wrought fitting), SB-564 (forging) or SB-446/SB-444 (bar, pipe).
   The form determines the spec.
2. B16.9 or B16.11?These are not interchangeable.
   B16.9 governs factory-made wrought butt-welding fittings; B16.11 governs
   forged socket-weld and threaded fittings. The end preparation and the
   pressure rating basis differ.
3. What schedule or wall thickness is the mating pipe?
   A B16.9 fitting must be ordered to the same wall thickness as the pipe it
   is welded to. Confirm the pipe standard as well — B36.10M for
   carbon steel, B36.19M for stainless.
4. Which fitting class is required?ASME SB-366 Table 1
   assigns classes to the WP grades. Class selection follows from the design
   pressure and temperature of the line, not from the alloy.
5. Is full traceability required?For pressure-critical
   service, request an EN 10204 3.1 mill test certificate matched to the heat
   number, and PMI on delivery.

For the alloy-specific chemistry and mechanical property tables, see our
grades pages: Inconel 625
butt weld fittings, Monel
400 butt weld fittings,
Hastelloy C-276 butt
weld fittings and
forged nickel
alloy socket weld fittings. For flange standard selection, see
ASME
B16.5 vs B16.47: which flange standard applies.