The Carbon Steel Eccentric Reducer is a butt weld fitting that transitions between two different pipe sizes, but unlike a concentric reducer, the centerline is offset. This offset allows the installer to choose orientation: Flat on Top (FOT) or Flat on Bottom (FOB). Flat on Top is used in horizontal liquid lines to prevent air pockets from forming at the high point of the reducer — air pockets can cause flow restriction and water hammer. Flat on Bottom is used in horizontal solids-carrying lines (sludge, slurry) to prevent sediment from accumulating in a low pocket. The fitting is manufactured from carbon steel to ASTM A234 WPB. Both ends are beveled per ASME B16.25. Eccentric reducers are required by API standards for pump suction piping.
Why Choose Us / Advantage
Flat Top or Flat Bottom Marked: “TOP” cast/stamped on the flat side to prevent installation error.
API 686 Compliant: Standard specification for pump suction reducers.
Full Material Traceability: Heat number on each fitting.
100% Hydro Tested: As a fitting (no leakage).
Short Lead Time: Standard sizes in 15-20 days.
Technical Data
★ Specification Flat on Top (FOT) Flat on Bottom (FOB)
★ Material ASTM A234 WPB ASTM A234 WPB
★ Use Horizontal liquid lines Horizontal slurry/solids lines
★ Prevents Air pockets Sediment accumulation
★ Pressure Sch10 – Sch160 Sch10 – Sch160
★ Size Range 3/4″ x 1/2″ – 48″ x 42″ 3/4″ x 1/2″ – 48″ x 42″
★ Standard ASME B16.9 ASME B16.9
★ Orientation Mark “TOP” on fitting “BOTTOM” or flat side down
Applications
● Centrifugal pump suction piping (eccentric, flat on top)
● Horizontal process piping where air pockets are a concern
● Sludge and slurry lines (flat on bottom)
● Plant utility water distribution
● Food and beverage processing lines (sanitary)
