ASTM A234 WPB Concentric Reducer | ASME B16.9 Carbon Steel Reducer

ASTM A234 WPB concentric reducers are carbon steel butt weld pipe fittings designed to provide a smooth and gradual transition between different pipe diameters in pressure piping systems.

Manufactured according to ASME B16.9, these concentric reducers provide:

• smooth flow transition
• reduced turbulence
• lower pressure loss
• reliable welding performance

ASTM A234 WPB concentric reducers are widely used in:

• oil & gas pipelines
• petrochemical plants
• power generation systems
• refineries
• industrial process piping

We are a professional manufacturer and exporter of ASTM A234 WPB concentric reducers & eccentric reducers

in China.

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What is ASTM A234 WPB Concentric Reducer?

A concentric reducer is a butt weld pipe fitting used to connect pipes of different diameters while maintaining a common centerline.

The reducer gradually changes the pipe size to:

• improve flow efficiency
• reduce turbulence
• minimize pressure drop

ASTM A234 WPB is the most commonly used carbon steel material for butt weld fittings intended for:

• moderate temperature service
• pressure piping systems

WPB reducers provide:

• excellent weldability
• good mechanical strength
• economical piping solutions

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Why Use Concentric Reducers?

Concentric reducers provide:

• smooth fluid transition
• lower turbulence
• reduced pressure loss
• improved flow efficiency
• better system stability

They are commonly used in:

• vertical pipelines
• pump discharge lines
• process piping systems

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ASTM A234 WPB Concentric Reducer Specifications

Specification	Details
Product Type	Concentric Reducer
Standard	ASME B16.9
Additional Standards	MSS SP-95 / DIN / JIS / GOST
Material	ASTM A234 WPB
Connection Type	Butt Weld
Manufacturing Type	Seamless / Welded
End Preparation	Beveled Ends
Surface Finish	Black Painted / Galvanized / Oiled

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Available Size Range

Seamless Reducers

• 1/2” – 24”
• DN15 – DN600

Welded Reducers

• 1/2” – 100”
• DN15 – DN2500

Custom dimensions are available according to project requirements.

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Wall Thickness Range

ASTM A234 WPB reducers are available in:

• SCH 10
• SCH 20
• SCH 30
• SCH STD
• SCH 40
• SCH 60
• SCH XS
• SCH 80
• SCH 100
• SCH 120
• SCH 140
• SCH 160
• XXS

Reducers can be manufactured according to customer specifications.

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ASTM A234 WPB Concentric Reducer Dimensions

Reducers are manufactured according to ASME B16.9 dimensional requirements.

 

NPS	O.D. D	O.D. D1	Length H
3/4 – 1/2	26.7	21.3	38
1 – 1/2	33.4	21.3	51
1 – 3/4	33.4	26.7	51
1.1/4 – 1/2	42.2	21.3	51
1.1/4 – 3/4	42.2	26.7	51
1.1/4 – 1	42.2	33.4	51
1.1/2 – 1/2	48.3	21.3	64
1.1/2 – 3/4	48.3	26.7	64
1.1/2 – 1	48.3	33.4	64
1.1/2 – 1.1/4	48.3	42.2	64
2 – 3/4	60.3	26.7	76
2 – 1	60.3	33.4	76
2 – 1.1/4	60.3	42.2	76
2 – 1.1/2	60.3	48.3	76
2.1/2 – 1	73	33.4	89
2.1/2 – 1.1/4	73	42.2	89
2.1/2 – 1.1/2	73	48.3	89
2.1/2 – 2	73	60.3	89
3 – 1.1/4	88.9	42.2	89
3 – 1.1/2	88.9	48.3	89
3 – 2	88.9	60.3	89
3 – 2.1/2	88.9	73	89
3.1/2 – 1.1/4	101.6	42.2	102
3.1/2 – 1.1/2	101.6	48.3	102
3.1/2 – 2	101.6	60.3	102
3.1/2 – 2.1/2	101.6	73	102
3.1/2 – 3	101.6	88.9	102
4 – 1.1/2	114.3	48.3	102
4 – 2	114.3	60.3	102
4 – 2.1/2	114.3	73	102
4 – 3	114.3	88.9	102
4 – 3.1/2	114.3	101.6	102
5 – 2	141.3	60.3	127
5 – 2.1/2	141.3	73	127
5 – 3	141.3	88.9	127
5 – 3.1/2	141.3	101.6	127
5 – 4	141.3	114.3	127
6 – 2.1/2	168.3	73	140
6 – 3	168.3	88.9	140
6 – 3.1/2	168.3	101.6	140
6 – 4	168.3	114.3	140
6 – 5	168.3	141.3	140
8 – 3.1/2	219.1	101.6	152
8 – 4	219.1	114.3	152
8 – 5	219.1	141.3	152
8 – 6	219.1	168.3	152
10 – 4	273	114.3	178
10 – 5	273	141.3	178
10 – 6	273	168.3	178
10 – 8	273	219.1	178
12 – 5	323.9	141.3	203
12 – 6	323.9	168.3	203
12 – 8	323.9	219.1	203
12 – 10	323.9	273	203
14 – 6	355.6	168.3	330
14 – 8	355.6	219.1	330
14 – 10	355.6	273	330
14 – 12	355.6	323.9	330
16 – 8	406.4	219	356
16 – 10	406.4	273	356
16 – 12	406.4	323.9	356
16 – 14	406.4	355.6	356
18 – 10	457	273	381
18 – 12	457	323.9	381
18 – 14	457	355.6	381
18 – 16	457	406.4	381
20 – 12	508	323.9	508
20 – 14	508	355.6	508
20 – 16	508	406.4	508
20 – 18	508	457	508
22 – 14	559	355.6	508
22 – 16	559	406.4	508
22 – 18	559	457	508
22 – 20	559	508	508
24 – 16	610	406.4	508
24 – 18	610	457	508
24 – 20	610	508	508
24 – 22	610	559	508

 

Detailed ASME B16.9 reducer dimension charts are available upon request.

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ASTM A234 WPB Reducer Weight Chart

Size	Schedule	Approx Weight
4” × 3”	SCH40	Approx. 3 – 5 kg
6” × 4”	SCH40	Approx. 8 – 12 kg
8” × 6”	SCH80	Approx. 20 – 30 kg

Actual reducer weight depends on:

• wall thickness
• manufacturing type
• reducer dimensions

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Concentric Reducer vs Eccentric Reducer

Property	Concentric Reducer	Eccentric Reducer
Centerline	Aligned	Offset
Typical Use	Vertical Pipelines	Horizontal Pipelines
Flow Characteristics	Symmetrical Flow	Prevents Air Pockets
Common Applications	Pump Discharge	Pump Suction

Choosing the correct reducer type improves:

• piping performance
• operational safety
• system efficiency

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Seamless vs Welded Reducers

Property	Seamless Reducer	Welded Reducer
Manufacturing Method	Formed from seamless pipe	Fabricated from plate
Size Range	Smaller Sizes	Large Diameters
Pressure Resistance	Higher	Good
Cost	Higher	Lower
Typical Applications	High Pressure Systems	Large Pipeline Systems

Seamless reducers are commonly used in:

• high-pressure service
• critical piping systems

Welded reducers are widely used for:

• large diameter pipelines
• lower cost piping projects

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ASTM A234 WPB Chemical Composition

Element	Requirement (%)
Carbon (C)	≤ 0.30
Manganese (Mn)	0.29 – 1.06
Phosphorus (P)	≤ 0.050
Sulfur (S)	≤ 0.058
Silicon (Si)	≥ 0.10
Chromium (Cr)	≤ 0.40
Molybdenum (Mo)	≤ 0.15
Nickel (Ni)	≤ 0.40
Copper (Cu)	≤ 0.40
Vanadium (V)	≤ 0.08

The balanced chemistry provides:

• good weldability
• reliable mechanical strength
• pressure piping performance

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Mechanical Properties of ASTM A234 WPB Reducers

Property	Requirement
Tensile Strength	415 – 585 MPa
Yield Strength	≥ 240 MPa
Elongation	≥ 20%

These mechanical properties ensure reliable performance in industrial pressure piping systems.

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Heat Treatment of ASTM A234 WPB Reducers

ASTM A234 WPB reducers are commonly supplied in:

• normalized condition
• normalized and tempered condition

Heat treatment improves:

• toughness
• weldability
• structural consistency

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Beveled Ends of ASTM A234 WPB Reducers

Reducers are commonly supplied with:

• 37.5° beveled ends
• ASME B16.25 welding preparation

Proper bevel machining ensures:

• easier welding
• reliable joint penetration
• high-quality butt weld connections

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Is ASTM A234 WPB Reducer NACE MR0175 Compliant?

ASTM A234 WPB reducers can be manufactured for sour service applications according to:

• NACE MR0175
• ISO 15156
• NACE MR0103

Additional sour service requirements may include:

• hardness control
• HIC testing
• PMI inspection
• low sulfur chemistry control

NACE compliant reducers are widely used in:

• oil & gas pipelines
• refinery systems
• H₂S service environments

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NACE MR0175 Hardness Requirements

For sour service applications:

• hardness control may be required
• HRC limits depend on project specifications

Additional testing can be supplied according to:

• customer requirements
• refinery specifications
• oil & gas project standards

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Manufacturing Method of Concentric Reducers

Typical manufacturing process includes:

• raw material cutting
• hot forming
• cold forming
• welding
• heat treatment
• bevel machining
• sand blasting
• dimensional inspection
• surface coating

Strict quality control ensures:

• dimensional accuracy
• wall thickness consistency
• reliable welding performance

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Surface Coating Options

ASTM A234 WPB reducers can be supplied with:

• black painting
• anti-rust oil
• hot dip galvanizing
• sand blasting

Surface coating depends on:

• transportation requirements
• storage conditions
• project specifications

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Marking of ASTM A234 WPB Reducers

Typical reducer marking includes:

• size
• wall thickness
• ASTM material grade
• heat number
• ASME standard
• manufacturer logo

Full traceability can be supplied according to project requirements.

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Inspection and Testing

ASTM A234 WPB concentric reducers can be supplied with:

• PMI testing
• UT (Ultrasonic Testing)
• RT (Radiographic Testing)
• MT (Magnetic Particle Testing)
• PT (Penetrant Testing)
• dimensional inspection
• visual inspection

Third-party inspection is available from:

• SGS
• BV
• TUV
• DNV

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Export Packing of Reducers

Reducers are packed in:

• plywood cases
• fumigation-free wooden cases
• export pallets

Pipe fitting ends can be protected using:

• plastic caps
• beveled end protectors

Suitable for international export transportation.

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Applications of ASTM A234 WPB Concentric Reducers

Oil & Gas Industry

Used in:

• transmission pipelines
• refinery piping
• offshore platforms

Petrochemical Plants

Suitable for:

• chemical transfer systems
• process piping

Power Generation

Applied in:

• steam systems
• cooling water piping

Industrial Piping Systems

Used in:

• water treatment plants
• compressed air systems
• utility piping

Their excellent weldability and cost efficiency make WPB reducers one of the most widely used carbon steel pipe fittings worldwide.

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Example Ordering Information

Example 1

Type: Concentric Reducer
Material: ASTM A234 WPB
Manufacturing Type: Seamless Butt Weld
Size: 8” × 6”
Wall Thickness: SCH 80
Ends: Beveled Ends
Standard: ASME B16.9

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Example 2

Type: Eccentric Reducer
Material: ASTM A234 WPB
Manufacturing Type: Seamless Butt Weld
Size: 10” × 8”
Wall Thickness: SCH 40
Ends: Beveled Ends
Standard: ASME B16.9

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ASTM A234 WPB vs ASTM A860 WPHY Reducers

Property	ASTM A234 WPB	ASTM A860 WPHY
Material Type	Carbon Steel	High Yield Carbon Steel
Yield Strength	≥ 240 MPa	Higher
Typical Application	General Pressure Piping	High Pressure Pipelines
Cost	Lower	Higher

WPB reducers are generally selected for standard industrial piping applications.

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Frequently Asked Questions

What is ASTM A234 WPB reducer?

ASTM A234 WPB reducer is a carbon steel butt weld fitting used to connect pipes of different diameters in pressure piping systems.

What is the difference between concentric and eccentric reducer?

Concentric reducers maintain centerline alignment, while eccentric reducers feature offset design for horizontal pipelines.

What is seamless reducer?

A seamless reducer is manufactured from seamless pipe material and is commonly used for high-pressure piping applications.

Can reducers be galvanized?

Yes. ASTM A234 WPB reducers can be supplied with hot dip galvanized coating.

What is SCH40 reducer?

SCH40 refers to the wall thickness schedule of the reducer.

How do you measure a concentric reducer?

Concentric reducers are measured by:

• large end size
• small end size
• wall thickness
• reducer length

Can ASTM A234 WPB reducers meet NACE MR0175 requirements?

Yes. NACE compliant reducers can be manufactured for sour service applications.

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Why Choose Our ASTM A234 WPB Reducers?

We provide:

• full material traceability
• strict dimensional inspection
• NACE compliant fittings
• custom dimensions
• export seaworthy packing
• fast delivery
• worldwide export support

Our ASTM A234 WPB concentric reducers are manufactured according to international standards for reliable industrial piping performance.