Aluminum Reducer

Henan Gnee New Material Co., Ltd. is one of the most reliable manufacturers and suppliers of aluminum reducer in China. With abundant experience, we warmly welcome you to wholesale high quality aluminum reducer in stock here from our factory. Good service and reasonable price are available.

 

GNEE supplies aluminum reducers for connecting pipes or tubes of different diameters in compatible piping systems. An aluminum reducer provides a transition from a larger pipe size to a smaller pipe size while keeping the flow path continuous.

 

Available types include concentric reducers and eccentric reducers, with butt-weld and threaded connections depending on the reducer design, size and manufacturing method.

 

For applicable factory-made wrought aluminum and aluminum-alloy welding fittings, ASTM B361 provides the material and product requirements. ASME B16.9 provides dimensional and related requirements for factory-made wrought butt-welding fittings. For applicable forged nonferrous threaded fittings including aluminum and aluminum alloys, ASME B16.52 may apply.

 

GNEE can supply standard and custom aluminum reducers according to alloy, temper, large-end size, small-end size, wall thickness, connection type and applicable standard.

Request a Quote for Aluminum Reducer

Aluminum Reducer Types

Aluminum reducers are mainly divided by the centerline relationship between the large and small ends.

Type	Centerline	Typical Use	Connection	Applicable Standard
Concentric Aluminum Reducer	Common centerline	General size transition, vertical or symmetrical piping	Butt Weld	ASTM B361 / ASME B16.9 where applicable
Eccentric Aluminum Reducer	Offset centerline	Horizontal piping, pump connections, drainage	Butt Weld	ASTM B361 / ASME B16.9 where applicable
Threaded Reducer	Depends on design	Small-bore piping and equipment connections	NPT / BSP / Metric	ASME B16.52 where applicable
Custom Reducer	According to drawing	Special size or installation requirements	Custom	According to agreed specification

The applicable standard depends on the fitting type, manufacturing method and connection. The standard should be confirmed before production.

Concentric vs Eccentric Aluminum Reducer

Selection Factor	Concentric Reducer	Eccentric Reducer
Centerline	Common centerline	Offset centerline
Shape	Symmetrical	Asymmetrical
Common Application	Vertical or symmetrical layouts	Horizontal and elevation-sensitive layouts
Pump Suction	Can be used where suitable	Often preferred in certain horizontal suction arrangements
Drainage	General	Can help maintain a controlled elevation
Installation Orientation	Generally not orientation-sensitive	Flat-up or flat-down should be specified
Main Advantage	Centered and symmetrical transition	Maintains alignment on one side

Important: Concentric and eccentric reducers are selected according to the piping layout and service conditions, not by a simple vertical-versus-horizontal rule.

 

Connection Types of Aluminum Reducer

Butt-Weld Aluminum Reducer

A butt-weld aluminum reducer is welded directly to the mating pipe or tube. The fitting ends are prepared and aligned with the mating pipe before welding. This creates a permanent connection for fabricated piping systems.

For applicable factory-made wrought aluminum and aluminum-alloy welding fittings, ASTM B361 is the relevant material and product specification. ASME B16.9 provides dimensional and related requirements for applicable factory-made wrought butt-welding fittings.

 

Threaded Aluminum Reducer

A threaded aluminum reducer uses internal or external pipe threads to connect with compatible threaded pipe or components.

Common thread specifications include:

NPT

BSPT

BSPP

Metric threads where specified

NPT, BSP and metric threads are different thread systems and are not interchangeable. The customer should specify the thread standard, thread size, male or female thread, and large-end and small-end dimensions.

For applicable forged nonferrous threaded fittings made from aluminum and aluminum alloys, ASME B16.52 may apply. The exact reducer design should be confirmed before production because not every threaded size-transition fitting falls under the same dimensional standard.

 

Aluminum Reducer Dimensions

For butt-welding fittings, ASME B16.9-2024 covers factory-made wrought butt-welding fittings from NPS 1/2 through NPS 48 (DN15 through DN1200). The standard covers overall dimensions, tolerances, ratings, testing and marking.

For reducers, the end-to-end dimension H is based on the large-end NPS. The OD values are determined by the large-end and small-end pipe sizes.

Common Reducer Reference Dimensions

NPS (Large x Small)	DN (Large x Small)	OD Large (mm)	OD Small (mm)	End-to-End H (mm)
3/4 x 1/2	20 x 15	26.7	21.3	38
1 x 3/4	25 x 20	33.4	26.7	51
1-1/2 x 1-1/4	40 x 32	48.3	42.2	64
2 x 1-1/2	50 x 40	60.3	48.3	76
2-1/2 x 2	65 x 50	73.0	60.3	89
3 x 2	80 x 50	88.9	60.3	89
4 x 3	100 x 80	114.3	88.9	102
5 x 4	125 x 100	141.3	114.3	127
6 x 4	150 x 100	168.3	114.3	140
8 x 6	200 x 150	219.1	168.3	152
10 x 8	250 x 200	273.0	219.1	178
12 x 10	300 x 250	323.8	273.0	203

Note: These are standard dimensional references for the specified ASME B16.9 reducer configurations. The end-to-end dimension H is based on the large-end NPS. Actual dimensions should be confirmed against the applicable edition of ASME B16.9 and the actual product specification before production.

For reducing combinations not listed above, GNEE can evaluate production according to a drawing or detailed dimensions.

 

Specifying Reducer Sizes

Aluminum reducers may be specified using NPS, DN or actual outside diameter (OD) depending on the piping system.

NPS (Nominal Pipe Size) - commonly used in North American piping specifications

DN (Nominal Diameter) - commonly used in international and European specifications

OD - for aluminum tubing systems, the actual OD can be more important than NPS or DN

When ordering a reducer for aluminum tube rather than standardized process pipe, customers should provide:

Large-end OD

Small-end OD

Wall thickness

This helps avoid dimensional mismatch between the reducer and mating tube.

Send an Inquiry Now

Technical Specifications

Parameter	Specification
Product	Aluminum Reducer
Types	Concentric / Eccentric
Connection	Butt Weld / Threaded / Custom
Large-End Size	NPS / DN / OD according to design
Small-End Size	NPS / DN / OD according to design
GNEE Standard Supply Range	NPS 1/2–24 where applicable (confirm with GNEE)
Larger Sizes	Available for evaluation on request
Wall Thickness	According to applicable standard, pipe dimensions or customer drawing
Alloys	6061, 6063, 5083, 5086, 3003, 1060 and other suitable aluminum alloys
Temper	According to alloy, manufacturing process and material specification
Butt-Weld Standard	ASTM B361 / ASME B16.9 where applicable
Threaded Standard	ASME B16.52 where applicable to forged nonferrous fittings
Thread	NPT / BSP / Metric where applicable
Surface	Mill Finish / Anodized / Customer-Specified Finish
Manufacturing	Formed / Forged / Machined / Fabricated according to design
Inspection	Visual / Dimensional / Material Verification / Additional Testing on Request
Packaging	Carton / Wooden Case / Wooden Pallet according to size and shipping requirements

Note: Wall thickness, size range and alloy availability are not universal across all reducer types. Final specifications should be confirmed according to the actual product design and applicable standard.

 

About Pipe Schedule

Where compatible with the applicable fitting and pipe dimensions, customers may specify pipe schedules such as SCH10, SCH40 or SCH80. However, pipe schedule should not be treated as a standalone pressure rating for an aluminum reducer.

The actual pressure capability depends on factors including alloy, temper, wall thickness, reducer geometry, fitting size, operating temperature, connection method, applicable design code and service conditions.

 

Aluminum Alloy Selection

Different aluminum alloys provide different combinations of strength, corrosion resistance, weldability, formability and machinability.

Alloy	Main Characteristics	Potential Applications
6061	Good strength, machinability and weldability	Industrial piping, equipment connections, compressed air
6063	Good extrusion characteristics and surface finish	Lightweight tubing and selected piping applications
5083	Good corrosion resistance and weldability	Marine and offshore applications
5086	Good corrosion resistance and weldability	Marine and corrosion-resistant systems
3003	Good formability and corrosion resistance	Selected general-purpose and fabricated applications
1060	High aluminum content and excellent corrosion resistance	Low-strength applications where suitable

 

Aluminum Reducer Standards

Reducer Type	Applicable Standard
Butt-Weld Concentric Reducer	ASTM B361 / ASME B16.9 where applicable
Butt-Weld Eccentric Reducer	ASTM B361 / ASME B16.9 where applicable
Threaded Reducer	ASME B16.52 where applicable

The exact standard should always be confirmed against the actual product design, manufacturing method and purchase specification.

ASTM B361

ASTM B361-16(2024) - Standard Specification for Factory-Made Wrought Aluminum and Aluminum-Alloy Welding Fittings

This is the ASTM product specification for factory-made wrought aluminum and aluminum-alloy welding fittings. For an aluminum butt-weld reducer, ASTM B361 may be specified for the fitting material and product requirements together with the applicable dimensional standard.

ASME B16.9

ASME B16.9-2024 - Factory-Made Wrought Buttwelding Fittings

ASME B16.9 covers overall dimensions, tolerances, ratings, testing and marking for factory-made wrought butt-welding fittings in sizes NPS 1/2 through NPS 48 (DN15 through DN1200). For aluminum butt-weld reducers, B16.9 is the key dimensional reference.

ASME B16.52

ASME B16.52-2024 - Forged Nonferrous Fittings, Socket-Welding and Threaded

This standard covers forged fittings made from nonferrous materials including aluminum and aluminum alloys, with socket-welding and threaded ends. It is relevant to applicable threaded aluminum fittings. It should not be presented as a universal standard for every aluminum reducer - the actual fitting design and manufacturing method must first be established.

 

Applications of Aluminum Reducer

Industrial Process Piping

Aluminum reducers can be used to transition between different pipe sizes in compatible industrial piping systems and distribution lines.

Pump and Equipment Connections

Reducers can match different pipe sizes at pump connections, valve connections, tank nozzles, heat exchangers, manifolds and process equipment. For pump suction applications, eccentric reducer orientation should be determined from the piping design.

Compressed-Air Systems

Aluminum reducers can connect different line sizes in compressed-air distribution systems where the material and fitting design are suitable for the operating conditions.

HVAC

Aluminum reducers can provide size transitions in compatible HVAC and air-handling systems.

Marine Piping

Aluminum alloys such as 5083 and 5086 can be considered for compatible marine piping systems where low weight, corrosion resistance and weldability are required. The selected alloy and temper should be matched to the marine environment and project specification.

Drainage Systems

Eccentric reducers can be considered where maintaining pipe elevation and drainage characteristics is important.

11. Inspection and Quality Control

GNEE can arrange inspection according to the agreed product specification and purchase order.

Material Inspection

Alloy verification

Temper verification

Chemical composition documentation

Material certificate review

Dimensional Inspection

Large-end OD

Small-end OD

Wall thickness

Overall length (H)

Concentricity or eccentricity

End preparation

Thread dimensions where applicable

Surface Inspection

Cracks, dents, scratches, deformation, surface damage

Additional Testing (depending on purchase specification)

PMI

Dye penetrant testing

Pressure testing where applicable

Customer-specified inspection

Inspection requirements should be agreed before production.

 

 

12. Packaging

GNEE uses export packaging designed to protect aluminum reducers during handling, loading and international transportation.

Typical packaging includes:

Individual protective bags

Plastic film

Kraft paper

Cartons

Wooden cases

Wooden pallets

Strapping

Small reducers can be packed in cartons and secured on wooden pallets. Larger reducers can be protected with suitable packaging materials and secured on pallets or inside wooden cases. Packaging can be adjusted according to container loading requirements, fitting size, quantity, destination and customer packaging instructions.

 

 

13. FAQ

Is a concentric reducer only used in vertical pipes?

No. Concentric reducers are commonly used in vertical or symmetrical piping layouts, but they are not restricted to vertical piping. The correct reducer depends on the piping design.

Is an eccentric reducer always used in horizontal pipes?

No. Eccentric reducers are commonly considered for horizontal piping, but their use depends on the system layout and service requirements.

Which reducer is better for pump suction?

For certain horizontal pump suction arrangements, an eccentric reducer may be preferred because the flat side can be oriented to reduce the possibility of an air or vapor pocket. The actual orientation should be determined by the piping design and pump manufacturer's requirements.

What standard covers aluminum butt-weld reducers?

Applicable factory-made wrought aluminum and aluminum-alloy welding reducers can be specified according to ASTM B361, while ASME B16.9 provides dimensional and related requirements for applicable factory-made wrought butt-welding fittings.

Are aluminum reducers available as seamless?

The manufacturing method depends on the size, alloy, geometry and required specification. Some aluminum reducer designs may be produced from extruded or other wrought material, while others may require forming, fabrication, forging or machining. "Seamless" should not be specified without confirming the actual manufacturing route and product specification.

What is the standard end-to-end length of an aluminum reducer?

For applicable butt-weld reducers, the end-to-end dimension H is established by the applicable ASME B16.9 configuration and is based on the large-end NPS. The actual dimension depends on the large-end size, small-end size, concentric or eccentric design, and applicable standard edition. For custom reducers, the required overall length can be specified by drawing.

Can aluminum reducers be made in 6061?

Yes. 6061 can be considered for suitable applications where its strength, machinability and weldability meet the project requirements.

Can 5083 aluminum reducers be used for marine applications?

Suitable 5083 aluminum reducers can be considered for marine applications. The final alloy, temper, wall thickness, welding procedure and service conditions should be confirmed for the specific project.

Can SCH40 or SCH80 be specified for aluminum reducers?

Where applicable, aluminum reducers can be designed to match compatible pipe dimensions specified by a pipe schedule. However, SCH40 or SCH80 should not be treated as the standalone pressure rating of an aluminum reducer. Pressure capability depends on alloy, temper, wall thickness, geometry, temperature, connection and applicable design requirements.

What sizes of aluminum reducers are available?

ASME B16.9 covers factory-made wrought butt-welding fittings from NPS 1/2 through NPS 48. GNEE's actual supply range depends on fitting type, alloy, manufacturing method and production capability.

Can GNEE manufacture custom aluminum reducers?

Yes. GNEE can evaluate custom reducers according to drawings, samples or detailed dimensional requirements. Please provide the large-end OD, small-end OD, wall thickness, overall length, concentric or eccentric geometry, alloy, temper, connection type and quantity.

Hot Tags: aluminum reducer, China aluminum reducer manufacturers, suppliers, factory