Eccentric Reducer

Eccentric reducer is a type of pipe fitting with different diameters at both ends and non overlapping centerlines. It is mainly used to connect pipes of different diameters, while avoiding the formation of air pockets or liquid pockets in the pipeline system through an eccentric structure, ensuring smooth flow of the medium. It is widely used in fields such as petroleum, chemical, and water supply and drainage. The following provides a detailed analysis of its structural characteristics, classification, working principles, and application scenarios:

1、 Basic structure of eccentric reducer

The eccentric reducer is composed of cylinders with different diameters at both ends, and the key feature is that the centerlines at both ends are not collinear (there is eccentricity). The specific structural parameters include:

Big end diameter (D): the diameter of one end connected to a large-diameter pipeline;

Small end diameter (d): the diameter of one end connected to a small-diameter pipeline;

Eccentricity (e): The distance between the centerlines of both ends (usually e=(D - d)/2, ensuring a smooth transition);

Length (L): The distance between the two end ports measured along the centerline of the major end, which must comply with standards such as GB/T 12459 and ASME B16.9.

Its structure can be simply understood as an "eccentric conical frustum", which achieves a transition in diameter from large to small through inclined side walls, different from concentric reducers (whose centerlines coincide at both ends).

2、 Core Category: Divided by Plane Position

According to the position of the "flat surface" (i.e. keeping one side of the pipe wall flush) of the eccentric reducer, it can be divided into two common types with different applicable scenarios:

Flat on Top eccentric reducer

Features: The top wall of the reducer remains flat, and the bottom has a sloping transition (the bottom of the large end is lower than the bottom of the small end).

Function: To prevent gas accumulation at the top of the pipeline (airbag), suitable for gas or steam pipelines, ensuring smooth gas flow and preventing gas blockage.

Flat on Bottom eccentric reducer

Features: The bottom wall of the reducer remains flat, and the top has a sloping transition (the top of the large end is higher than the top of the small end).

Function: To prevent the accumulation of liquid (liquid bags) at the bottom of the pipeline, suitable for liquid pipelines (especially for media containing solid particles such as sewage and mud), and to prevent the deposition of media from blocking the pipeline.