What is the difference between concentric and eccentric reducers?
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What are the differences between concentric and eccentric reducers, and how should one choose between them when using them?
Reducers, also known as size converters, are used to connect pipes of different sizes； Generally, it is divided into two types: concentric reducer pipes and eccentric reducer pipes. When the reducer pipe is placed upright and the projections of its two ends are concentric circles, it is called a concentric reducer pipe; whereas in the case of an eccentric reducer pipe, the projections consist of a smaller circle inscribed within a larger circle. The selection should take into account the properties of the material and the design of the downstream pipelines. For eccentricity, factors such as material discharge and material impact are considered in the selection process.
A concentric reducing fitting has its center at one direction, with a uniform reduction between the larger and smaller ends. An eccentric large end fitting is one in which the centers of the large end and the small end are at the same position; it is divided into eccentric large end fittings with parallel tops and those with parallel bottoms. The large-end flat heads are used in gas transmission, such as at the compressor outlet, to prevent gas accumulation. Flat-bottomed reducing nozzles are widely used in liquid transfer, such as in the inlet pipelines of centrifugal pumps, to prevent liquid accumulation.
Concentric reducers are commonly used on vertical pipes, while eccentric reducers are often used on horizontal pipes
Additional note: Concentric designs are generally used in vertical pipes, while eccentric designs come in top-aligned and bottom-aligned versions. Taking the pump inlet as an example, if the inlet pipe is above the pump’s inlet opening, a bottom-aligned design is used at the pump inlet; if the pipe is below the inlet opening, a top-aligned design is used.