Standard Sizes
3" x 2"3" NPS x 2" NPS (DN 80 x DN 50)
4" x 3"4" NPS x 3" NPS (DN 100 x DN 80)
6" x 4"6" NPS x 4" NPS (DN 150 x DN 100)
8" x 6"8" NPS x 6" NPS (DN 200 x DN 150)
12" x 8"12" NPS x 8" NPS (DN 300 x DN 200)
Product page
SKYLAND
ASME B16.9 Buttweld Eccentric Reducer
Skyland Eccentric Buttweld Reducers are engineered with one straight/flat side and one tapered side, offsetting the centerlines of the two connected pipe diameters. Indispensable for horizontal piping runs, they allow installation with 'Flat on Bottom' (FOB) to prevent liquid pooling and facilitate complete drainage, or 'Flat on Top' (FOT) on pump suction lines to eliminate air/vapor entrapment and cavitation.
Standard compliance: ASME / ANSI B16.9, DIN 2616-1, MSS SP-75, and EN 10253
Enables Flat on Bottom (FOB) and Flat on Top (FOT) horizontal piping configurations
Sizes: 3/4" x 1/2" up to 48" x 40" (DN 20 x DN 15 to DN 1200 x DN 1000)
Wall schedules: Sch 10S, 40S, STD, 80S, XS, 120, 160, XXS
Ready for quotationShare your range, connection and case requirement.
Talk to ATHStandardASME / ANSI B16.9, DIN 2616-1, MSS SP-75, EN 10253
Size Range3/4" x 1/2" to 48" x 40"
SchedulesSch 10S to XXS
OrientationFlat on Top (FOT) or Flat on Bottom (FOB)
MaterialsCarbon Steel A234 WPB, Stainless 316L, Duplex 2205
CertificationsPED 2014/68/EU, ISO 9001:2015, EN 10204 3.1
Technical Specifications
ASME B16.9 Eccentric Reducer Matrix
Select large and small nominal diameters for eccentric buttweld reducers.
GeometryOffset Flat Side
Sizes3/4"x1/2" to 48"x40"
SchedulesSch 10 to XXS
StandardASME B16.9 / DIN 2616-1
Part Number Example
SKL-ER-060-040-SCH80-316L
SKLBrandSkyland Metal & Alloys
ERTypeEccentric Buttweld Reducer
060Large End6" NPS (DN 150)
040Small End4" NPS (DN 100)
SCH80ScheduleSchedule 80
316LMaterialASTM A403 WP316L
Technical specifications
Design CodeASME B16.9 / DIN 2616-1 / MSS SP-75
Bevel EndsASME B16.25 standard weld prep
Operational Notes
Flat on Top (FOT) prevents gas pockets in liquid pump suction lines.
Flat on Bottom (FOB) ensures condensate drainage in steam and vapor lines.
Engineering & Piping Guidelines
In liquid lines feeding pump suctions, eccentric reducers are installed Flat on Top (FOT) to prevent air pockets from forming at the top of the reducer, which would otherwise starve the pump impeller and cause severe cavitation.
In steam or two-phase lines, installing eccentric reducers Flat on Bottom (FOB) ensures condensed liquid drains freely along the pipe bottom without damming.