A reducer is a component in a pipeline that reduces the pipe size from a larger to a smaller bore (inner diameter).
The length of the reduction is usually equal to the average of the larger and smaller pipe diameters. There are two main types of reducer:
concentric and eccentric reducers.
A reducer can be used either as a nozzle or as diffuser depending on the mach number of the flow.
A reducer allows for a change in pipe size to meet hydraulic flow requirements of the system or to adapt to existing piping of a different size. Reducers are usually concentric but eccentric reducers are used when required to maintain the same top-or bottom-of-pipe level.
These fittings are manufactured in inch and metric size.
An eccentric reducer is a fitting used in piping systems between two pipes of different diameters. They are used where the diameter of the pipe on the upstream side of the fitting (i.e. where the flow is coming from) is larger than the downstream side. Unlike a concentric reducer, which resembles a cone, eccentric reducers have an edge that is parallel to the connecting pipe. This parallel edge results in the two pipes having offset center lines. The same fitting can be used in reverse as an eccentric increaser/expander.
Horizontal liquid reducers are always eccentric, top flat (unless on control set, same as PV, TV, HV, LV) or (pipe rack), which prevents the build-up of air bubbles in the system. Eccentric reducers are used at the suction side of pumps to ensure air does not accumulate in the pipe. The gradual accumulation of air in a concentric reducer would result in a large bubble that could eventually cause the pump to stall or cause cavitation when drawn into the pump.
The word eccentric in regards to piping is commonly pronounced "e-sentrik" (spelled "ecentric"). This has become an industry standard and is widely taught in schools.
Horizontal gas reducers are always eccentric, bottom flat, which allows condensed water or oil to drain at low points.
Reducers in vertical lines are generally concentric unless the layout dictates otherwise.
EN10025-5 S235J0W Weathering steel Plate is especially intended for use in welded bolted and riveted components, which shall have enhanced resistance to atmospheric corrosion, for service at ambient temperatures, this structural steels with improved atmospheric corrosion resistance.