ASTM A106 Gr B ReducerASTM A234 · ASME B16.9 · Manufacturer, trader & exporter, India
SA-106 Gr B · Seamless carbon steel pipe
An ASTM A106 Gr B reducer is a fitting that joins two pipes of different sizes, for use with ASTM A106 Gr B pipe. ASTM A106 Gr B itself is a pipe or plate specification, so the matching reducer is made to ASTM A234 WPB — which is what we supply for A106 B lines. Concentric reducers keep the centreline in line and suit vertical lines. Eccentric reducers keep one side flat — flat on top at pump suctions to avoid air pockets, flat on the bottom in pipe racks.
- ASTM A234
- ASME B16.9
- 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 Reducer?
- What it is
- A fitting that joins two pipes of different sizes
- Material
- ASTM A234 WPB
- Dimensions
- ASME B16.9 · MSS SP-43
- Grade
- ASTM A106 Gr B
- Best at
- High-temperature process and steam piping in refineries and power plants
ASTM A106 Gr B Reducer Specification
| Product | ASTM A106 Gr B Reducer |
|---|---|
| Material standard | ASTM A234 WPB |
| Dimensional standard | ASME B16.9 · MSS SP-43 |
| Sizes | ½" – 48" |
| Wall / class | Sch 5S – XXS, to match pipe |
| Ends | Bevelled to ASME B16.25 |
| Testing | Chemical & mechanical per heat · NDT · impact where specified |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose a Reducer
Concentric reducers keep the centreline in line and suit vertical lines. Eccentric reducers keep one side flat — flat on top at pump suctions to avoid air pockets, flat on the bottom in pipe racks.
- Concentric and eccentric
- Flat-top on pump suction
- Seamless or welded
More on choosing: Reducer guide.
ASTM A106 Gr B Reducer: Why A106 B for reducers
Concentric reducers keep the centreline in line and suit vertical lines. Eccentric reducers keep one side flat — flat on top at pump suctions to avoid air pockets, flat on the bottom in pipe racks. In ASTM A106 Gr B, 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 | Carbon and low-alloy fittings suit hydrocarbon, steam and utility lines. ASTM A106 Gr B is picked for high-temperature process and steam piping in refineries and power plants. |
|---|---|
| Typical service | Refineries — Process and steam lines. |
| Welding to carbon steel | Matching carbon or low-alloy filler is used; joints to stainless need ER309L |
| Matching filler | ER70S-6 / E7018 |
ASTM A106 Gr B Reducer Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Chromium | As specified |
| Copper | As specified |
| Nickel | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A106 Grade B.
ASTM A106 Gr B Reducer Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A106 Grade B — condition per order.
Full chemistry, properties and equivalents are on the ASTM A106 Gr B grade page.
Other ASTM A106 Gr B pipe fittings
ASTM A106 Gr B Reducer dimensions — ASME B16.9
Values in mm, the same for every material; the wall thickness matches the pipe schedule.
| NPS | OD | Reducer length H |
|---|---|---|
| ½" | 21.3 | — |
| ¾" | 26.7 | 38 |
| 1" | 33.4 | 51 |
| 1½" | 48.3 | 64 |
| 2" | 60.3 | 76 |
| 3" | 88.9 | 89 |
| 4" | 114.3 | 102 |
| 6" | 168.3 | 140 |
| 8" | 219.1 | 152 |
| 10" | 273.1 | 178 |
| 12" | 323.9 | 203 |
| 16" | 406.4 | 356 |
| 20" | 508.0 | 508 |
| 24" | 610.0 | 508 |
Full chart: ASME B16.9 fitting dimensions.
ASTM A106 Gr B Reducer — questions buyers ask
Why use an eccentric reducer at a pump suction?
Installed flat side up, it prevents air pockets that can cause cavitation.
Can ASTM A106 Gr B reducers be welded to carbon steel?
Yes — matching carbon or low-alloy filler is used; joints to stainless need ER309L.
Which standard covers ASTM A106 Gr B reducers?
The material is ASTM A234 WPB; dimensions follow ASME B16.9 · MSS SP-43. 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 reducer?
The steel price, the size and schedule or 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 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026