IBR Approved · Buttweld Fittings
Buttweld Pipe Reducer Manufacturer
Concentric and eccentric reducers to ASME B16.9 — in carbon, alloy, stainless and duplex steel. 1/2" to 48" NB, SCH 20 to XXS. IBR approved with Form IV (Part D) (formerly Form III-C), EN 10204 3.1 / 3.2 traceable.
Overview
Buttweld reducers join two different pipe sizes in a single formed component to ASME B16.9. Concentric reducers keep a common centre-line and are used on vertical runs; eccentric reducers offset the centre-line with one flat side, used on horizontal runs to control gas and liquid pockets — commonly on pump suction piping.
Every reducer is produced to the applicable material specification with full traceability, supplied with EN 10204 3.1 or 3.2 test certificates and, for boiler and steam service, IBR Form IV (Part D) certification.
Reducer Types & Standards
| Type | Centre-line | Standard | Typical Use |
|---|---|---|---|
| Concentric Reducer | Common / shared | ASME B16.9 | Vertical runs, pump discharge |
| Eccentric Reducer | Offset / flat side | ASME B16.9 | Horizontal runs, pump suction |
| Swage Nipple | Con. or ecc. | MSS SP-95 / BS 3799 | Small-bore size transitions |
Available Material Grades
Buttweld reducers are supplied in our full material range. Click a grade for full specification, chemistry and mechanical data:
Technical Specifications
| Parameter | Range |
|---|---|
| Size range | 1/2" to 48" NB (larger on enquiry) |
| Schedules | SCH 20, STD, XS, SCH 80, SCH 160, XXS |
| Dimensional standard | ASME B16.9 (MSS SP-75 for large OD) |
| End preparation | Bevel end per ASME B16.25 |
| Certification | EN 10204 3.1 / 3.2 · IBR Form IV (Part D) |
| Testing | PMI, dimensional, DP / RT as specified |
Testing & Inspection
- ✓ Chemical and mechanical testing against the ordered ASTM / ASME material specification
- ✓ PMI (positive material identification) and visual and dimensional inspection to ASME B16.9
- ✓ NDT (DP / MPI, UT or RT) as your specification requires
- ✓ EN 10204 3.1 certificate as standard; 3.2 witnessed by Bureau Veritas, TÜV, Lloyd’s Register, SGS, DNV or your own inspector
- ✓ IBR Form IV (Part D) for Indian boiler piping
Export Documents & Packing
- ✓ Commercial invoice, packing list and certificate of origin
- ✓ Heat-number traceability on every piece
- ✓ Seaworthy wooden cases or pallets, bevel ends protected, marked to your instructions
- ✓ FOB, CFR or CIF terms — see how an export order works
Frequently Asked Questions
What is the difference between a concentric and eccentric reducer?
A concentric reducer is symmetrical about a shared centre-line and is used on vertical pipe runs and where the pipe centre-line must stay constant. An eccentric reducer has one side flat (offset centre-line) and is used on horizontal runs — flat side up to vent gas, or flat side down to drain liquid — for example on pump suction lines to avoid air pockets. Both are made to ASME B16.9.
What size range of reducers do you manufacture?
We manufacture concentric and eccentric buttweld reducers from 1/2 inch to 48 inch NB in schedules from SCH 20 through XXS, across carbon, alloy, stainless and duplex grades, all with EN 10204 3.1 or 3.2 certification and IBR Form IV (Part D) (formerly Form III-C) where applicable. Swage nipples are available for smaller size transitions.
Which certificates and documents come with your buttweld reducers?
EN 10204 3.1 certificates as standard, 3.2 with third-party inspection, IBR Form IV (Part D) (formerly Form III-C) where the fittings are for Indian boiler piping, plus export documents: commercial invoice, packing list and certificate of origin.