ASTM A335 P11 ReducerASTM A234 · ASME B16.9 · Manufacturer, stockist & exporter, India
SA-335 P11 · 1¼Cr-½Mo alloy pipe
An ASTM A335 P11 reducer is a fitting that joins two pipes of different sizes, for use with ASTM A335 P11 pipe. ASTM A335 P11 itself is a pipe or plate specification, so the matching reducer is made to ASTM A234 WP11 — which is what we supply for P11 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 A335 P11 Reducer?
- What it is
- A fitting that joins two pipes of different sizes
- Material
- ASTM A234 WP11
- Dimensions
- ASME B16.9 · MSS SP-43
- Grade
- ASTM A335 P11
- Best at
- Steam and hot-oil piping up to about 550 °C
ASTM A335 P11 Reducer Specification
| Product | ASTM A335 P11 Reducer |
|---|---|
| Material standard | ASTM A234 WP11 |
| 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 · 3.2 with third-party inspection |
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
ASTM A335 P11 Reducer Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 1.00 – 1.50 |
| Molybdenum | 0.44 – 0.65 |
| Carbon | 0.05 – 0.15 |
| Manganese | 0.30 – 0.60 |
| Silicon | 0.50 – 1.00 |
| Phosphorus | 0.025 max |
| Sulphur | 0.025 max |
ASTM A335 P11 Reducer Mechanical Properties
| Minimum values | Value |
|---|---|
| Tensile strength | 415 MPa · 60 ksi |
| Yield strength 0.2% | 205 MPa · 30 ksi |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the ASTM A335 P11 grade page.
Other ASTM A335 P11 pipe fittings
ASTM A335 P11 Reducers for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A335 P11 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 A335 P11 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.
Which standard covers ASTM A335 P11 reducers?
The material is ASTM A234 WP11; 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 A335 P11 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 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