BUTTWELD REDUCERS

BUTTWELD REDUCERS

CONCENTRIC REDUCER

The open ends of a concentric reducer are aligned and centered one to the other. Generally, this type of pipe reducer is used to modify the bore size of the pipeline by two (maximum three) measures, to avoid an excessive pressure drop in the pipeline.

If a larger reduction is needed, then a sequence of reducers shall be used to have a smooth and gradual adjustment of the pipeline bore size (vs. a drastic change).

For small bore size reductions, reducing flanges may be an alternative to buttweld reducers.

ECCENTRIC REDUCER

The open ends of an eccentric reducer are in an “offset” position one to the other.

Eccentric reducers are used, generally, for pipelines installed in a horizontal position (whereas concentric reducers are used for pipelines installed vertically or for the inlets of suction pumps, as top flat eccentric reducers).

TOP AND BOTTOM FLAT ECCENTRIC REDUCER

Eccentric reducers can be top flat (“TF”) or bottom flat (“BF”).

The bottom flat eccentric reducer type is used for pipe-racks (the bottom of the reducer is flat and at the same level of the bigger sized run pipe), while the top flat pipe reducer type is used at the inlet of piping suction pumps as shown in the image below (this setup prevents the formation of vapor traps in the pipeline):

Top flat and bottom flat eccentric reducer for suction pump

CONCENTRIC VS ECCENTRIC REDUCER

The key difference between concentric vs eccentric reducer is the centricity of the inlet vs. the outlet of the fitting, which is perfect for a concentric reducer and offset of an eccentric reducer.

BW REDUCER MANUFACTURING PROCESS

Cold forming is the most common manufacturing process for seamless eccentric/concentric reducers (welded reducers are produced with the single or double seam weld process):