ASME B16.9 | Concentric Pipe Reducers | Butt-Welding Pipe Fittings | NPS 1/2″–48″ | Carbon Steel, Stainless Steel, Duplex, Alloy & Nickel Alloys
Elite Buttweld Concentric Reducers are factory-made pipe fittings used to connect two pipes of different nominal diameters while maintaining a common centerline. The conical reducer design provides a gradual transition between pipe sizes and is widely used in process, utility and industrial piping systems.
Elite supplies Concentric Reducers in seamless, welded and fabricated construction, with carbon steel, stainless steel, duplex, alloy steel, nickel alloy, copper-nickel and other materials available according to applicable standards and project requirements.
| Parameter | Specification |
|---|---|
| Manufacturer | Elite |
| Product | Buttweld Concentric Reducer |
| Primary Standard | ASME B16.9 |
| Configuration | Concentric Reducer |
| Centerline | Common centerline between large and small ends |
| Size Range | NPS 1/2"–48" |
| Large End Size | As specified |
| Small End Size | As specified |
| Construction | Seamless / Welded / Fabricated |
| End Connection | Butt Weld |
| Wall Thickness | SCH 5S, 10S, 20, 40S, STD, 80S, XS, 100, 120, 140, 160, XXS and custom |
| Dimensions | ASME B16.9 where applicable |
| End Preparation | ASME B16.25 where applicable |
| Material Standards | ASTM / ASME applicable specifications |
| Heat Treatment | According to material and applicable specification |
| Surface Finish | Pickled / Blasted / Polished / Coated / Project Specified |
| Inspection | Visual, dimensional, PMI, UT, RT, MT, PT, hardness and other NDE as specified |
| Documentation | MTC, EN 10204 3.1/3.2, inspection reports and project documentation |
| Configuration | Description |
|---|---|
| Concentric Reducer | Large and small ends share a common centerline |
| Seamless Reducer | Seamless construction for applicable sizes/materials |
| Welded Reducer | Welded construction for selected sizes/materials |
| Fabricated Reducer | Custom large-diameter or special construction |
| Custom Reducer | Special dimensions manufactured to approved drawings |
| Note: A Concentric | Reducer maintains a common centerline. An Eccentric Reducer has offset centerlines and is a separate product configuration. |
ASME B16.9
Primary dimensional standard for factory-made wrought buttwelding fittings, including Concentric Reducers.
ASME B16.25
Butt-welding end preparation.
ASTM / ASME Material Specifications
Applicable material standards according to the selected material and grade.
ASME B31.3 / B31.1
Process and power piping requirements, where applicable.
NACE MR0175 / ISO 15156
For sour-service applications when specifically required by the project.
ASME Section II
Material requirements where applicable to pressure equipment and project specifications.
Note: ASME B16.28 should not be listed as the primary standard for Concentric Reducers. Current applicable wrought fitting dimensions are covered by ASME B16.9.
Carbon Steel
ASTM A234 WPB, WPC and applicable WPHY grades including WPHY 42, WPHY 46, WPHY 52, WPHY 60, WPHY 65 and WPHY 70.
Low Temperature Carbon Steel
ASTM A420 WPL3, WPL6 and other applicable grades.
Stainless Steel
ASTM A403 WP304/304L, WP316/316L, WP321/321H, WP347/347H and other applicable grades.
Duplex & Super Duplex
ASTM A815 grades including UNS S31803, S32205, S32750 and S32760.
Alloy Steel
ASTM A234 WP1, WP5, WP9, WP11, WP12, WP22 and WP91.
Nickel Alloys
ASTM B366 and applicable specifications for Nickel 200/201, Monel 400/K500, Inconel 600/601/625/800/825, Hastelloy C276 and Alloy 20.
Copper-Nickel Alloys
Applicable Cu-Ni grades including UNS C70600 and C71500.
Titanium
Applicable titanium grades manufactured to the relevant ASTM specification, including ASTM B363 where applicable.
Material selection is based on operating pressure, temperature, process fluid, corrosion conditions, mechanical requirements and applicable project specifications.
Standard Concentric Reducer
Large and small ends share the same centerline, providing a symmetrical conical transition.
Seamless Concentric Reducer
Seamless construction for applicable sizes, materials and wall thicknesses.
Welded Concentric Reducer
Welded construction for selected sizes and materials where permitted by the applicable specification.
Fabricated Concentric Reducer
Custom-fabricated reducers for large diameters, heavy wall thicknesses and special configurations.
Standard Concentric Reducer dimensions are manufactured in accordance with ASME B16.9, where applicable.
Available wall thicknesses include:
SCH 5S, 10S, 20, 40S, STD, 80S, XS, 100, 120, 140, 160 and XXS, together with project-specific wall thicknesses.
Ordering dimensions should identify both the large-end size and small-end size, for example:
For large-diameter, heavy-wall or fabricated reducers, dimensions can be manufactured according to approved engineering drawings.
Elite Concentric Reducers are manufactured using suitable forming, welding and fabrication processes according to material, size and project requirements.
Quality control can include:
Elite can manufacture Concentric Reducers according to customer drawings, piping isometrics and project specifications, including:
Depending on project requirements, supply can include:
Elite Buttweld Concentric Reducers are used in:
Concentric Reducers are commonly selected where a symmetrical transition and common pipe centerline are required.
When ordering Buttweld Concentric Reducers, please specify:
| Item | Required Information |
| Product | Buttweld Concentric Reducer |
| Large End Size | NPS |
| Small End Size | NPS |
| Material & Grade | ASTM / ASME specified grade |
| Wall Thickness | Schedule or actual thickness |
| Construction | Seamless / Welded / Fabricated |
| Standard | ASME B16.9 or project specified |
| Reducer Length | Standard / Project Specified |
| End Preparation | ASME B16.25 or project specified |
| Surface Finish | Standard / Pickled / Blasted / Polished / Coated |
| Inspection | PMI / UT / RT / MT / PT / Hardness etc. |
| Documentation | EN 10204 3.1 / 3.2 and project documents |
| Quantity | Required quantity |
| Special Requirements | Drawing, coating, NACE, testing or other project requirements |
Typical Order Example:
6″ × 4″ Concentric Reducer, ASME B16.9, ASTM A234 WPB, SCH 40, Seamless, ASME B16.25 Bevel Ends, EN 10204 3.1, PMI.
