Product Overview
Carbon steel reducers (concentric and eccentric) are pipe fittings that join two pipes of different diameters, reducing flow area smoothly while maintaining pressure integrity. As essential fittings in process piping, reducers are specified by ASME B16.9 (wrought butt-welding), MSS SP-75, or EN 10253-2. Huaxia-Steel supplies seamless and welded reducers from NPS 3/4″ × 1/2″ up to 48″ × 24″, Sch 10 – XXS, in A234 WPB and equivalent grades — factory-direct from certified Chinese fitting mills.

Specifications
| Parameter | Range | Standard / Tolerance |
|---|---|---|
| Size (large × small) | 3/4″×1/2″ – 48″×24″ (DN20×15 – DN1200×600) | ASME B16.9 dimension tables |
| Types | Concentric (symmetric) / Eccentric (flat side) | Eccentric: flat side up (pump suctions) or down (racks) per order |
| Wall schedule | Sch 10 – 160, STD, XS, XXS | Wall tolerance −12.5% per B16.9 |
| Manufacture | Seamless (hot pressed) or welded | Hot forming from pipe/plate, heat treated |
| Ends | Beveled per ASME B16.25 | 30° +5/−0° bevel, 1.6 mm land |
| Standard | ASME B16.9, MSS SP-75, EN 10253-2, GOST 17378 | State on order |
Available Grades
| Standard | Grade | Use |
|---|---|---|
| ASTM A234 | WPB (most common), WPC | Carbon steel, moderate/high temperature |
| ASTM A420 | WPL6 | Low temperature service (−46°C) |
| EN 10253-2 | P235GH, P265GH | European pressure piping |
| JIS B2311/2312 | STPG, SPP | Japanese-spec piping |
Manufacturing Standards
- Hot pressing: pipe section heated and pressed over a die to taper the diameter — the dominant process for seamless reducers; wall thickness redistribution controlled per B16.9 limits.
- Welded reducers: formed from plate segments (fabricated) for large sizes; seam NDE per project spec.
- Heat treatment: normalizing for WPB standard; heat treatment record stated on MTC.
- Concentric vs eccentric: eccentric reducers keep one side flat — critical for pump suction lines (avoid air pockets) and pipe racks (constant bottom-of-pipe elevation).
- Marking: grade, size, schedule, heat number, standard stamped or inked on body.

Applications
- Refinery and petrochemical process piping (A234 WPB industry default)
- Pump suction and discharge lines (eccentric, flat side up on suction)
- Power plant steam and feedwater systems
- Fire protection mains and water transmission
- Compressed air, HVAC, and utility headers
Quality Assurance
- EN 10204 3.1 certificate per heat: chemistry, tensile, heat treatment
- Dimensional report: large/small end OD, overall length, wall, ovality, bevel angle
- Surface & NDE: MT/PT on formed areas; UT/RT optional per project spec
- Hydro or air pressure testing available for project requirements
- Third-party inspection (SGS / BV / TÜV) welcomed before packing

Packaging & Shipping
- Plywood cases or steel pallets; plastic end caps protect bevels
- Small reducers packed in cartons inside cases with heat-number packing list for site traceability
- Large-diameter reducers shipped individually crated or loose in bulk
- 20ft/40ft container loading or bulk shipment per size mix
Huaxia-Steel supplies ASME B16.9 carbon steel reducers — concentric and eccentric, seamless and welded — from NPS 3/4″ × 1/2″ to 48″ × 24″ with full certification and factory-direct pricing. Send us your reducer list (size × size, schedule, standard) for a quotation within 24 hours.





