Butt Weld Reducers – Concentric & Eccentric
Brandfittings supplies ASME B16.9 butt weld reducers in both concentric and eccentric types, in carbon steel (ASTM A234 WPB), stainless steel (ASTM A403 WP304/304L, WP316/316L), alloy and low-temperature grades. Reducers transition between pipe sizes in oil & gas, chemical, power and water systems — and the choice between concentric and eccentric directly affects flow behavior and drainage. Every reducer ships with a mill test certificate (EN 10204 3.1).
As a factory in Mengcun County, Hebei — China's Pipe Fittings Capital — we manufacture reducers from 1/2″ × 3/8″ up to 48″ × 42″, in seamless and welded construction, with any size combination available on request.
Concentric vs Eccentric Reducers
- Concentric reducer (CRC) — both ends are centered on the same axis. Ideal for vertical lines, pump suction where vibration damping matters, and general pipe size transitions.
- Eccentric reducer (ERE) — the two centerlines are offset, keeping one side of the pipe level. Used on horizontal liquid lines: flat side up prevents air pockets, flat side down allows full drainage.
For horizontal liquid service, eccentric reducers are normally required by piping codes to avoid trapped air or liquid accumulation. Our engineers can recommend the right type for your line orientation and fluid.
Specifications
| Parameter | Details |
|---|---|
| Type | Concentric Reducer (CRC), Eccentric Reducer (ERE) |
| Size Range | 1/2″ × 3/8″ – 48″ × 42″; custom combinations available |
| Wall Thickness | SCH 5S – SCH XXS |
| Construction | Seamless (small sizes) and welded (large sizes) |
| المعايير | ASME B16.9, MSS-SP-75, GOST 17378, JIS B2312, GB/T 12459 |
| Ends | Beveled ends per ASME B16.25, ready for butt welding |
| Documentation | MTC EN 10204 3.1, heat numbers, third-party inspection reports (SGS/BV/TÜV) |
Available Materials
| Material Grade | Standard | Typical Application |
|---|---|---|
| A234 WPB | ASTM | General carbon steel piping |
| A403 WP304/304L | ASTM | Corrosion-resistant, food grade |
| A403 WP316/316L | ASTM | Marine, chemical, high corrosion |
| A420 WPL6 | ASTM | Low temperature service |
| A234 WP5 / WP9 / WP11 / WP22 / WP91 | ASTM | High temperature / alloy |
Carbon steel WPB covers most utility duty; stainless 304/316 suits corrosive and hygienic media; alloy and WPL6 grades handle high-temperature and low-temperature service. See our material buying guide for selection help.
Applications by Industry
- النفط والغاز — pipeline diameter transitions and pump station piping. Explore oil & gas pipe fittings →
- Chemical Processing — process line size changes in stainless and alloy. Explore chemical industry fittings →
- توليد الطاقة — boiler and steam line transitions. Explore power generation fittings →
- Shipbuilding & Marine — Class-approved engine room and seawater lines. Explore marine fittings →
- معالجة المياه — header-to-distribution size transitions. Explore water treatment fittings →
Manufacturing & Quality Control
Reducers are formed by hot pressing or cold forming from certified pipe, then heat-treated as required — normalized for carbon steel, solution-annealed for stainless. Seamless reducers are produced for small-bore sizes; large diameters are longitudinally welded and fully radiographed where required. Each piece is dimensionally inspected to ASME B16.9 (end diameters, length, wall thickness, eccentricity), with heat numbers stamped and mirrored on the MTC. Third-party inspection by SGS, BV or TÜV can be arranged before shipment.
Customization Options
- Custom size combinations — any large-to-small transition, including non-standard pairs
- Custom wall thickness — per schedule or special requirements
- Surface treatment — galvanizing, epoxy coating, pickling & passivation
- Marking & packing — per your specification, export-grade packing
Why Choose Brandfittings Reducers?
- Concentric & eccentric available – Horizontal & vertical runs
- Seamless & welded options – Per project requirements
- Custom size combinations – Non-standard transitions available
- Full certification – MTC EN 10204 3.1 included
- Certified quality – ISO 9001 / ISO 14001 / CCS / TS certified facility
Check current price levels in our Cangzhou pipe fittings price reference, or read our guide to choosing the right pipe fittings.
Frequently Asked Questions
When should I use a concentric vs an eccentric reducer?
Use a concentric reducer on vertical lines and where the pipe is supported to handle the offset. On horizontal liquid lines, use an eccentric reducer — flat side up to avoid air pockets, flat side down to allow full drainage — as required by most piping codes.
What standards do your reducers comply with?
All our reducers are manufactured to ASME B16.9, with MSS-SP-75, GOST 17378, JIS B2312 and GB/T 12459 also available. Every order ships with an MTC per EN 10204 3.1.
What size range do you supply?
Standard range is 1/2″ × 3/8″ up to 48″ × 42″, in SCH 5S to SCH XXS. Any custom size combination can be manufactured on request.
Are your reducers seamless or welded?
Small-bore reducers are seamless; large diameters are longitudinally welded and can be radiographed where the specification requires it.
What are your lead times?
Standard sizes in stock ship in 7–10 days. Production orders take 30–45 days, and custom items 45–60 days, depending on size, material and quantity.