ASTM A106 Gr B Expander FlangeASTM A105 · ASME B16.5 (flange end) · Manufacturer, stockist & exporter, India
SA-106 Gr B · Seamless carbon steel pipe · EXP
An ASTM A106 Gr B expander flange is a weld neck flange whose hub increases the pipe size, for use with ASTM A106 Gr B pipe. ASTM A106 Gr B itself is a pipe or plate specification, so the matching expander flange is made to ASTM A105 — which is what we supply for A106 B lines. Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- ASTM A105
- 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 an ASTM A106 Gr B Expander Flange?
- What it is
- A weld neck flange whose hub increases the pipe size
- Material
- ASTM A105
- Dimensions
- ASME B16.5 (flange end)
- Grade
- ASTM A106 Gr B
- Best at
- High-temperature process and steam piping in refineries and power plants
ASTM A106 Gr B Expander Flange Specification
| Product | ASTM A106 Gr B Expander Flange |
|---|---|
| Material standard | ASTM A105 |
| 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 | Chemical & mechanical per heat · NDT · impact where specified |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose an Expander Flange
Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- Increases one or two pipe sizes
- Saves a weld and space
- Weld neck design
ASTM A106 Gr B Expander Flange Chemical Composition
| Element | Weight % |
|---|---|
| Carbon | 0.30 max |
| Manganese | 0.29 – 1.06 |
| Silicon | 0.10 min |
| Phosphorus | 0.035 max |
| Sulphur | 0.035 max |
| Chromium | 0.40 max |
| Copper | 0.40 max |
| Nickel | 0.40 max |
ASTM A106 Gr B Expander Flange Mechanical Properties
| Minimum values (elongation varies with wall) | Value |
|---|---|
| Tensile strength | 415 MPa · 60 ksi |
| Yield strength 0.2% | 240 MPa · 35 ksi |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the ASTM A106 Gr B grade page.
Other ASTM A106 Gr B flanges
ASTM A106 Gr B Expander Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A106 Gr B Expander Flange — questions buyers ask
When is an expander flange used?
Most often at pump and valve outlets where the line size increases immediately.
Which standard covers ASTM A106 Gr B expander flanges?
The material is ASTM A105; 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 ASTM A106 Gr B expander flange?
The steel 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