Aluminum reducers are aluminum pipe fittings used to connect two pipes of different diameters. They are usually made of aluminum because of its light weight, corrosion resistance, and low cost. Aluminum reducers can be concentric, meaning that their centerlines coincide with the centerline of the pipe, or eccentric, meaning that their centerlines do not coincide.

Concentric and eccentric reducers are maximum resistance to pressure, gradual change in pipe diameter and minor pressure drop. These reducer fittings are designed to be installed easily with optimal performance in different systems. They have been designed to work on high-pressure systems and other environmental challenges, giving more durable solutions.

The reducers are standard in various grades, finishes, and sizes to serve various needs of the intended applications. The conical shape provides the best flow characteristics while the construct reduces the fluid's swirling, creating positive effects in many industrial uses.

In engineering and industrial applications, aluminum reducers are used in a variety of fluid transfer systems such as water, air and other chemicals. They allow for a smooth transition of fluids from one size of pipe to another, and are therefore important in the design of piping systems. Aluminum reducers can be manufactured by machining or casting, and are available in different sizes and models depending on the application.

Concentric and Eccentric Reducer Specification:

Types of Aluminum Reducer:

Aluminum reducer fittings can be divided into concentric and eccentric.

1. Concentric Reducer

Structural characteristics:

Geometric symmetry: the center axis of the pipes at both ends coincide, and the diameter changes along the axis of symmetrical transition (e.g. DN100 → DN80).

Smooth gradient: the bore is tapered, the angle is usually ≤ 30 °, to reduce turbulence and pressure drop.

Schematic diagram:

Big end (DN100) → tapering section → small end (DN80)  

(centerline aligned, section shrinks uniformly)

Application Scenario:

Vertical piping: Fluid flow by gravity (e.g. high level tank outlet) to avoid fluid accumulation.

High flow rate system: need to reduce the pressure drop of the scene (such as ventilation ducts, cooling water circulation).

Symmetrical flow field requirements: laboratory equipment, precision instrument piping connections.

Advantages:

Low fluid resistance, low energy loss.

No restriction on installation direction, wide applicability.

2. Eccentric Reducer

Structural characteristics:

Axis offset: the center axis of the big end and the small end are parallel but offset by a certain distance (usually offset = diameter difference / 2).

Flat bottom design: one side is kept flat and the other side is tilted and contracted (e.g. DN100→DN80).

Schematic diagram:

Big end (DN100) → offset tapering section → small end (DN80)  

(Flat bottom side aligned, top side tilted and contracted)

Application Scenario:

Gas systems: Installation with flat bottom side up to prevent liquid stagnation (e.g. compressed air piping).

Liquid systems: Installation with flat bottom facing downwards to avoid gas stagnation (e.g. pump inlet).

Impurity-sensitive systems: sewage treatment, slurry transfer to minimize solids deposits.

Advantages:

Adapts to horizontal piping gas-liquid separation needs, reducing the risk of clogging.

Optimizes suction conditions for pumping equipment and prevents cavitation.

Concentric Reducer vs Eccentric Reducer

Available Sizes of Aluminium Reducers:  

Aluminum reducer sizes are usually expressed in nominal diameters (DN) or inches (''). With 3 inches corresponding to DN80 (outside diameter of approximately 88.9mm) and 4 inches corresponding to DN100 (outside diameter of approximately 114.3mm).

Common combinations of reducers include:

3''→4'' (DN80→DN100): suitable for pipeline expansion needs, such as compressed air system or tanker unloading port.

4''→3'' (DN100→DN80): for reduction scenarios, commonly used in industrial equipment interface adaptation.

Available Types of Aluminum Reducer Fitting:

The Manufacturing Process of Aluminum Reducer:

1. Material selection: aluminum alloy (such as 6061, 7075) or special alloys (such as high-temperature resistant aluminum-silicon alloy).

2. Molding process:

Die-casting molding: suitable for complex structures (such as gas storage tank joints with reinforcement), machining threads and sealing surfaces after one-time molding.

Cold/Hot Processing: Adjust the tube diameter by cold drawing or hot extrusion to suit different size requirements.

3. Processing and treatment:

Stress relief treatment: Artificial aging or preheating after rough machining to reduce subsequent deformation (e.g. dimensional shrinkage during U-groove milling).

Surface treatment: anodized or sprayed to enhance corrosion resistance.

4. Welding and testing: TIG/MIG welding process is used to ensure the strength of the weld, and the sealing is verified by pressure test.