Eccentric Reducer
Product Introduction
Key Features
- Offset centerline design; one outer edge is kept flush flat
- Effectively eliminates air pockets at pipeline high points, guarantees stable liquid delivery
- Prevents pump cavitation, widely preferred for horizontal liquid service lines
Executed Standards
- ASME B16.9
- EN 10253
- GB/T 12459, GB/T 13401
- MSS SP-75
Available Materials
- Carbon Steel: A234 WPB, P245GH, Q235B
- Stainless Steel: A403 WP304, WP316L
- Alloy Steel: A234 WP11, A234 WP22
Technical Parameters
- Size Range: 1/2” ~ 48” / DN15 ~ DN1200
- End Connection: Butt Weld (BW), optional Socket Weld / Threaded ends
- Pressure Class: Class 150 ~ Class 2500, PN6 ~ PN160
Application
Categories
Product Introduction
Eccentric Reducer is a diameter-transition pipe fitting where the central axes of large and small bore are offset. One side keeps a straight flat tangent surface, primarily installed on horizontal pipelines to avoid air accumulation and vapor lock inside piping.
Key Features
- Offset centerline design; one outer edge is kept flush flat
- Effectively eliminates air pockets at pipeline high points, guarantees stable liquid delivery
- Prevents pump cavitation, widely preferred for horizontal liquid service lines
Executed Standards
- ASME B16.9
- EN 10253
- GB/T 12459, GB/T 13401
- MSS SP-75
Available Materials
- Carbon Steel: A234 WPB, P245GH, Q235B
- Stainless Steel: A403 WP304, WP316L
- Alloy Steel: A234 WP11, A234 WP22
Technical Parameters
- Size Range: 1/2” ~ 48” / DN15 ~ DN1200
- End Connection: Butt Weld (BW), optional Socket Weld / Threaded ends
- Pressure Class: Class 150 ~ Class 2500, PN6 ~ PN160
Application
Petrochemical, water treatment, oil & gas, power plant, chemical process horizontal liquid pipelines. Custom eccentric reducers can be produced according to your drawings and special requirements.
Relate Ptoduct
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Concentric Reducer
-
Eccentric Reducer
-
90 Degree Pipe Elbows
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45 Degree Pipe Elbows
-
180 degree pipe elbows
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Welding Flange
-
Threaded Flange
-
Socket Weld Flange
-
Slip On Neck Flange
-
Lap Joint Flange
-
ISO DIN EN1092-1flange
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Flat-Face (FF) Flange
-
Blind Flange
Specifications
| Item | Range |
|---|---|
| Size | 1/2″ – 48″ reducing to 1/2″ – 40″ |
| Wall thickness | SCH10 – SCH160, STD, XS, XXS |
| Standard | ASME B16.9, DIN 2616, JIS B2311, GB/T 12459 |
| Materials | A234 WPB, A420 WPL6, A403 WP304/304L/316/316L |
| Certificates | EN 10204 3.1; 3.2 on request |
Eccentric vs Concentric Reducer – Which One?
An eccentric reducer keeps one side of the reduction flat (offset bore), a concentric reducer tapers symmetrically around the centerline. The rule: horizontal lines that must not trap air or vapor use eccentric reducers, flat side up – so gas bubbles cannot accumulate at the taper. Pump suctions use eccentric reducers flat side down (flat top would create a vapor pocket at the pump inlet). Vertical lines and general flow reduction use concentric.
Applications
Eccentric reducers appear at pump suctions (flat-side-down installation is standard practice to prevent cavitation), at pipe rack transitions between different line sizes, on gravity-drained lines where a concentric taper would hold liquid against the flow, and anywhere the bottom of the pipe must stay aligned – e.g. over pipe supports. Choosing the wrong orientation is one of the most common piping installation errors, so many specs state it explicitly on the drawing.
FAQs
Which side is flat on a pump suction reducer? Flat side down (bottom-of-pipe level). This keeps the top of the line tapered so vapor travels with the flow into the pump instead of pocketing.
Can eccentric reducers be custom-made? Yes – non-standard reductions, extra walls and special offsets are manufactured to drawing in 15-30 days. Send your spec for a quote.