Sheet 18/77Products / Steel and structural / Concentric reducerRev
Steel and structural · catalogue item
Concentric reducer
Butt-weld fitting that joins two pipe sizes on a common centerline.
In short
Butt-weld fitting that joins two pipe sizes on a common centerline. JJ Projects sources it to the specification the buyer names. Typical reference, standards: ASME B16.9.
Specification references
Typical references only. The governing specification is the one on your purchase order or datasheet.
| Property | Typical reference |
|---|---|
| Standards | ASME B16.9 |
| Materials | ASTM A234 WPB (carbon), A403 (stainless) |
| End connections | Beveled ends for butt welding |
| Size | Large and small NPS, with wall schedule for each end |
Specification references describe what the order names, not a certification held by JJ Projects.
Steel and structural
Typical uses
- 01Changing line size on vertical runs and in racks
- 02Matching pipe size to equipment nozzles and valves
- 03Transitions after pumps and in headers
- 04Stainless and alloy piping where a size change is needed
What to include in a request
A request with these details can be quoted without a round of questions. Send what you have and we will ask for the rest.
- 01Large-end NPS and small-end NPS, for example 8 x 6
- 02Wall thickness or schedule for each end
- 03Concentric or eccentric type
- 04Material and grade, for example ASTM A234 WPB or A403 WP316L
- 05Seamless or welded construction, if the specification allows both
- 06Quantity
- 07Documents: material test report and any examination or marking requirement
Steel and structural
Related items
- 0190° long radius elbowButt-weld 90 degree long radius elbows to ASME B16.9 in ASTM A234 WPB and A403, and what a fittings request needs to be quoted, by NPS and schedule.Learn more
- 02Equal teeButt-weld equal tees to ASME B16.9 in ASTM A234 WPB and A403, sized by NPS and schedule, and what to include in a request for equal tees so it can be quoted.Learn more
- 03Seamless pipeSeamless carbon and stainless pipe by NPS and schedule, sourced to ASTM A106, A312 and API 5L, with the details a pipe request should carry.Learn more
- 04Centrifugal pumpCentrifugal process pumps to API 610 and ASME B73.1, supplied to your datasheet, and what a request needs: fluid, flow, head, NPSH available and materials.Learn more
Guides
Guides
- 01Pipe schedules: NPS, OD and wall thicknessNPS is a label, not a measurement. Learn how pipe schedule sets wall thickness under ASME B36.10M and B36.19M, with OD and wall tables for NPS 2, 4, 6 and 8.Learn more
- 02Material test reports (MTRs) and EN 10204What a material test report contains, how EN 10204 types 2.1, 2.2, 3.1 and 3.2 differ, what heat numbers mean, and what to check against the purchase order.Learn more
Questions
Questions
01When is an eccentric reducer used instead of a concentric one?
An eccentric reducer keeps one side of the pipe flat. It is common on pump suction lines, with the flat side up, to avoid trapping vapor, and on horizontal lines where the bottom must stay level for drainage. A concentric reducer keeps both ends on one centerline.
02Do I need to give the schedule at both ends?
Yes. Each end is beveled to match the pipe it welds to, so the large end and the small end may have different wall thicknesses. State both.
Send the specification. We will take it from there.
A material list, a drawing or a single line: tell us what the project needs and where it is going.