ASME B16.28 covers ratings, overall dimensions, tolerances, testing, and markings for factory-made wrought short-radius elbows and returns in sizes NPS 1/2 through NPS 48.
Key Dimensions Covered by ASME B16.28
90-degree Short Radius Elbows
180-degree Short Radius Return Bends
Although originally written for carbon and low-alloy steels, the standard is explicitly permitted for high-nickel alloys, including Hastelloy X, when the material conforms to a listed ASTM specification and the pressure-temperature ratings are calculated per the applicable piping code.
Hastelloy X Chemical Composition
Nominal Chemical Composition of Hastelloy X (Weight %)
|
Element |
Content (%) |
Element |
Content (%) |
|
Nickel (Ni) |
47 (Balance) |
Tungsten (W) |
0.6 |
|
Chromium (Cr) |
22.0 |
Carbon (C) |
0.1 |
|
Iron (Fe) |
18.0 |
Manganese (Mn) |
1.0 max |
|
Molybdenum (Mo) |
9.0 |
Silicon (Si) |
1.0 max |
|
Cobalt (Co) |
1.5 |
Boron (B) |
0.008 max |
Hastelloy X Physical and Mechanical Properties
Density: 8.3 g/cm³
Melting Point: 1260-1355°C
Room Temperature Tensile Strength: ≥690 MPa
Yield Strength (0.2% Offset): ≥310 MPa
Elongation: ≥30%
The alloy has excellent creep and stress-rupture strength at elevated temperatures, with significant retention of mechanical properties even at temperatures approaching 980°C.
Hastelloy X BW Fittings Characteristics
Solid-solution strengthened Ni-Cr-Fe-Mo alloy.
Excellent oxidation resistance up to 1200 °C (2200 °F).
High creep-rupture strength above 650 °C (1200 °F).
Good fabricability and weldability with matching filler metal ERNiCrMo-2 or ERNiCr-3.
Widely used in gas-turbine combustion liners, afterburners, furnace rolls, petrochemical furnace tubes, and high-temperature heat exchangers.
ASME B16.28 Hastelloy X Product Forms
|
Fitting Type |
Radius |
Center-to-Face (A) per B16.28 |
Typical Schedules / Wall Thickness |
|
90° Short Radius Elbow (SR) |
1 × NPS |
Table 2 of B16.28 |
Sch 10S, Sch 40S, Sch 80S, XS, XXS |
|
180° Short Radius Return (SR) |
1 × NPS |
Table 3 of B16.28 |
Same as above |
Note: ASME B16.28 does not cover long-radius elbows (1.5D), tees, reducers, or caps - these fall under ASME B16.9. We supply those in Hastelloy X to B16.9 when required.
ASME B16.28 Dimensional Tolerances
|
Parameter |
Tolerance |
|
Outside diameter at bevel |
±1.6 mm (NPS ≤ 24) |
|
Center-to-face (A) |
±3.2 mm |
|
Wall thickness |
Not less than 87.5 % of nominal |
|
Out-of-roundness |
≤ 1 % of nominal OD (max 5 mm for large sizes) |
|
Alignment (squareness) |
Bevel perpendicular to axis within 0.5° |
ASME B16.28 Hastelloy X BW Fittings Manufacturing Process
Starting material: solution-annealed seamless pipe or plate (ASTM B619, B622, B435).
Hot or cold forming followed by solution annealing at 1175 °C ± 15 °C (2150 °F ± 25 °F) with rapid cooling.
100 % radiographic examination of longitudinal welds (when welded fittings are supplied).
100 % dimensional inspection and surface finish verification.
Positive Material Identification (PMI) on every fitting.
Hydrostatic or pneumatic pressure testing available on request.
Marking: "B16" (case permitted), alloy "HX" or "N06002", heat number, size, schedule, manufacturer logo.
Certification: EN 10204 Type 3.1 or 3.2 with full traceability.
We maintain a ready stock of Hastelloy X SR 90° and 180° fittings from NPS 1/2 to NPS 12 in Sch 10S through Sch 80S, with larger sizes and custom wall thicknesses available on 4–8 week lead times. All products are supplied with original mill certificates under Haynes International license.
