ASME B16.9 Butt Weld Concentric Eccentric Reducer

ASME B16.9 Butt Weld Reducer Manufacturer & Supplier

We are a trusted manufacturer and supplier of ASME B16.9 Butt Weld Reducers, offering both Concentric Reducers and Eccentric Reducers for seamless pipeline transitions. Designed according to ASME B16.9 standards, our reducers are available in carbon steel, stainless steel, alloy steel, duplex, and nickel alloys, ensuring durability and reliability in oil & gas, petrochemical, power generation, and marine industries.

ASME B16.9 Butt Weld Reducers are important pipe fittings used to connect pipes of different diameters in process piping systems. They help maintain proper fluid flow and reduce turbulence or cavitation by gradually changing the pipe size.

These reducers are designed and manufactured according to ASME B16.9, which covers factory-made wrought butt-weld fittings for pressure piping systems.

What is a reducer?

Reducers are designed to change from pipe diameter in one direction. Standard there are 2 types the concentric reducer, is usually used in vertical pipe lines, and the eccentric reducer that is used in horizontal pipe lines.

Standard Overview

• Standard: ASME B16.9 – Factory-Made Wrought Buttwelding Fittings
• Type: Concentric Reducer,Eccentric Reducer
• Sizes: ½” NB to 48” NB (DN15 – DN1200)
• Schedule/Thickness: SCH 10S, 20, 40, 80, 160, XXS

Types of reducer

• Concentric Reducer – Symmetrical design, keeps pipe centerline consistent, ideal for vertical piping.
• Eccentric Reducer – Offset design, maintains bottom or top pipe level, prevents air pockets, widely used in horizontal piping.

Butt Weld Reducer Material for ASME B16.9

Wrought fittings covered by this Standard shall be in accordance with ASTM A234, ASTM A403, ASTM A420, ASTM A815, ASTM B361, ASTM B363, ASTM B366, or the corresponding specification listed in ASME BPVC, Section II. The term “wrought” denotes fittings made of pipe, tubing, plate, or forgings. For purposes of determining proof testing requirements of section 9, the materials are grouped by similar properties as shown in below table

Group No.	Material	Standards
1	Carbon and low – alloy steels	ASTM A234/A234M and ASTM A420/A420M
2	Austenitic and duplex stainless steels	ASTM A403/A403M and ASTM A815/A815M
3	Nickel alloys	ASTM B366/B366M
4	Aluminum alloys	ASTM B361
5	Titanium alloys	ASTM B363

Butt weld Reducer Materials Gade

• Carbon Steel: ASTM A234 WPB Reducer, WPC Reducer
• Alloy Steel: ASTM A234 WP5 WP9, WP11,WP12,WP22,WP91,WP92
• Stainless Steel: ASTM A403 WP304, WP304L, WP316, WP316L, WP321, WP347
• Nickel Alloys: Inconel, Monel, Hastelloy
• Duplex & Super Duplex Stainless Steel:ASTM A815 WPS31803 Reducer,ASTM A815 WPS32750 Reducer

Standard Marking Requirement for ASME B16.9 Butt Weld Reducer

Each elbow marks permanently , indicating the following content:
The name or trademark of the manufacturer
Material identification mark (ASTM or ASME level symbol)
Wall thickness serial number or nominal wall thickness
Specifications – Engineering pipe diameter (NPS) related to end connection should be used
Compliance – standard and special pipe fittings

Dimensions Butt Weld Reducers Con. & Ecc. ASME B16.9

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
26 – 18	660	457	610
26 – 20	660	508	610
26 – 22	660	559	610
26 – 24	660	610	610
28 – 18	711	457	610
28 – 20	711	508	610
28 – 24	711	610	610
28 – 26	711	660	610
30 – 20	762	508	610
30 – 24	762	610	610
30 – 26	762	660	610
30 – 28	762	711	610
32 – 24	813	610	610
32 – 26	813	660	610
32 – 28	813	711	610
32 – 30	813	762	610
34 – 24	864	610	610
34 – 26	864	660	610
34 – 30	864	762	610
34 – 32	864	813	610
36 – 24	914	610	610
36 – 26	914	660	610
36 – 30	914	762	610
36 – 32	914	813	610
36 – 34	914	864	610
38 – 26	965	660	610
38 – 28	965	711	610
38 – 30	965	762	610
38 – 32	965	813	610
38 – 34	965	864	610
38 – 36	965	914	610
40 – 30	1016	762	610
40 – 32	1016	813	610
40 – 34	1016	864	610
40 – 36	1016	914	610
40 – 38	1016	965	610

Dimensions are in millimeters unless otherwise indicated. Wall thickness (t) must be specified by customer.

Dimensional Tolerances of Concentric and Eccentric Reducers ASME B16.9

Nominal Pipe Size	1/2 to 2.1/2	3 to 3.1/2	4	5 to 8
Outside Diameter at Bevel (D)	+ 1.6 – 0.8	1.6	1.6	+ 2.4 – 1.6
Inside Diameter at End	0.8	1.6	1.6	1.6
Overall Length (H)	2	2	2	2
Nominal Pipe Size	10 to 18	20 to 24	26 to 30	32 to 48
Outside Diameter at Bevel (D)	+ 4 – 3.2	+ 6.4 – 4.8	+ 6.4 – 4.8	+ 6.4 – 4.8
Inside Diameter at End	3.2	4.8	+ 6.4 – 4.8	+ 6.4 – 4.8
Overall Length (H)	2	2	5	5
Wall Thickness (t)	Not less than 87.5% of Nominal Wall Thickness

Dimensions Butt Weld Tee ASME B16.9 Tolerance

NPS	DN	O.D	I.D	Off Angle, Q	Off Plane, P
1/2~2-1/2	15~65	+1.6, -0.8	±0.8	±1	±2
3~3-1/2	80~90	±1.6	±1.6	±2	±4
4	100	±1.6	±1.6	±3	±5
5~8	125~200	+2.4, -1.6	±1.6	±3	±6
10~18	250~450	+4.0, -3.2	±3.2	±4	±10
20~24	500~600	+6.4, -4.8	±4.8	±5	±10
26~30	650~750	+6.4, -4.8	±4.8	±5	±13
32~48	800~1200	+6.4, -4.8	±4.8	±5	±19

Technical Specifications

• Dimensions: As per ASME B16.9 & ANSI standards
• End Connections: Butt Weld Ends (beveled as per ASME B16.25)
• Manufacturing Process: Seamless, Welded, or Fabricated
• Testing & Certification:
  • Non-destructive testing (NDE)
  • PMI (Positive Material Identification)
  • EN 10204 3.1 / 3.2 certification
  • Third-party inspection (TÜV, SGS, BV, LR, DNV)

As a manufacturer and exporter of ASME B16.9 Butt Weld Reducers including Concentric and Eccentric types, made from carbon steel, stainless steel, alloy steel, duplex, and nickel alloys.
All fittings are supplied with EN 10204 3.1 or 3.2 MTC, and comply with NACE MR0175 / PED / AD2000 standards.

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