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Pipe Tee Dimensions, ASME B16,9 Pipe Tee, Equal Tee, Reducing Tee

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ASME B16.9 Pipe Tee Dimensions

Date:2025-12-18

In industrial piping systems, pipe tees are crucial fittings for achieving media diversion or convergence.

ASME B16.9 is one of the most widely used global standards for buttweld fittings, providing standardized specifications for key geometric dimensions of tees, elbows, reducers, and other fittings.

ASME B16.9 Standard

ASME B16.9 – Factory-Made Wrought Buttwelding Fittings

1. Applicable Pipe Diameter Range

NPS 1/2″ – 48″

2. Applicable Fitting Types Include

90° / 45° Elbows

Equal Tee

Reducing Tee

Concentric/Eccentric Reducers

Pipe Caps, etc.

Common Types of Pipe Tees

1. Straight Tee (Equal Tee)

Three ports with the same nominal size

Main pipe and branch pipe diameters are the same

Suitable for symmetrical flow distribution systems

Common representation:

NPS 6 × 6 × 6 Equal Tee

2. Reducing Tee

Main pipe size is the same, branch pipe size is smaller

Used for systems with different flow rates or pressures

Common representation:

NPS 8 × 8 × 4 Reducing Tee

Straight / Equal Tee Dimensions

ASME B16.9 Pipe Tee Dimensions
NOMINAL PIPE SIZE	OUTSIDE DIAMETER	CENTER TO END	LENGTH
inch.	OD mm	C mm	M mm
1/2	21.3	25	25
3/4	26.7	29	29
1	33.4	38	38
1 1/4	42.2	48	48
1 1/2	48.3	57	57
2	60.3	64	64
2 1/2	73	76	76
3	88.9	86	86
3 1/2	101.6	95	95
4	114.3	105	105
5	141.3	124	124
6	168.3	143	143
8	219.1	178	178
10	273.1	216	216
12	323.9	254	254
14	355.6	279	279
16	406.4	305	305
18	457.2	343	343
20	508	381	381
22	559	419	419
24	610	432	432
26	660	495	495
28	711	521	521
30	762	559	559
32	813	597	597
34	864	635	635
36	914	673	673
38	965	711	711
40	1016	749	749
42	1067	762	711
44	1118	813	762
46	1168	851	800
48	1219	889	838

Reducing Tee Dimensions

ASME B16.9 Pipe Tee Dimensions
NOMINAL PIPE SIZE	OUTSIDE DIAMETER		CENTER TO END
Inch	D mm	P mm	C mm	M mm
1/2 x 3/8	21.3	17.1	25	25
1/2 x 1/4	21.3	13.7	25	25
3/4 x 1/2	26.7	21.3	29	29
3/4 x 3/8	26.7	17.1	29	29
1 x 3/4	33.4	26.7	38	38
1 x 1/2	33.4	21.3	38	38
1 1/4 x 1	42.2	33.4	48	48
1 1/4 x 3/4	42.2	26.7	48	48
1 1/4 x 1/2	42.2	21.3	48	48
1 1/2 x 1 1/2	48.3	42.2	57	57
1 1/2 x 1	48.3	33.4	57	57
1 1/2 x 3/4	48.3	26.7	57	57
1 1/2 x 1/2	48.3	21.3	57	57
2 x 1 1/2	60.3	48.2	64	60
2 x 1 1/4	60.3	42.2	64	57
2 x 1	60.3	33.4	64	51
2 x 3/4	60.3	26.7	64	44
2 1/2 x 2	73	60.3	76	70
2 1/2 x 1 1/2	73	48.3	76	67
2 1/2 x 1 1/4	73	42.2	76	64
2 1/2 x 1	73	33.4	76	57
3 x 2 1/2	88.9	73	86	83
3 x 2	88.9	60.3	86	76
3 x 1 1/2	88.9	48.3	86	73
3 x 1 1/4	88.9	42.2	86	70
3 1/2 x 3	101.6	88.9	95	92
3 1/2 x 21/2	101.6	73	95	89
3 1/2 x 2	101.6	60.3	95	83
3 1/2 x 1 1/2	101.6	48.3	95	79
4 x 3 1/2	114.3	101.6	105	102
4 x 3	114.3	88.9	105	98
4 x 2 1/2	114.3	73	105	95
4 x 2	114.3	60.3	105	89
4 x 1 1/2	114.3	48.3	105	86
5 x 4	141.3	114.3	124	117
5 x 3 1/2	141.3	101.6	124	114
5 x 3	141.3	88.9	124	111
5 x 2 1/2	141.3	73	124	108
5 x 2	141.3	60.3	124	105
6 x 5	168.3	141.3	143	137
6 x 4	168.3	114.3	143	130
6 x 3 1/2	168.3	101.6	143	127
6 x 3	168.3	88.9	143	124
6 x 2 1/2	168.3	73	143	121
8 x 6	219.1	168.3	178	168
8 x 5	219.1	141.3	178	162
8 x 4	219.1	114.3	178	156
8 x 3 1/2	219.1	101.6	178	152
10 x 8	273.1	219.1	216	203
10 x 6	273.1	168.1	216	194
10 x 5	273.1	141.3	216	191
10 x 4	273.1	114.3	216	184
12 x 10	323.9	273.1	254	241
12 x 8	323.9	219.1	254	229
12 x 6	323.9	168.3	254	219
12 x 5	323.9	141.3	254	216
14 x 12	355.6	323.9	279	270
14 x 10	355.6	273.1	279	257
14 x 8	355.6	219.1	279	248
14 x 6	355.6	168.3	279	238
16 x 14	406.4	355.6	305	305
16 x 12	406.4	323.9	305	295
16 x 10	406.4	273.1	305	283
16 x 8	406.4	219.1	305	273
16 x 6	406.4	168.3	305	264
18 x 16	457	406.4	343	330
18 x 14	457	355.6	343	330
18 x 12	457	323.9	343	321
18 x 10	457	273.1	343	308
18 x 8	457	219.1	343	298
20 x 18	508	457	381	368
20 x 16	508	406.4	381	356
20 x 14	508	355.6	381	356
20 x 12	508	323.9	381	346
20 x 10	508	273.1	381	333
20 x 8	508	219.1	381	324
22 x 20	559	508	419	406
22 x 18	559	457	419	394
22 x 16	559	406.4	419	381
22 x 14	559	355.6	419	381
22 x 12	559	323.9	419	371
24 x 10	559	273.1	419	359
24 x 22	610	559	432	432
24 x 20	610	508	432	432
24 x 18	610	457	432	419
24 x 16	610	406.4	432	406
24 x 14	610	355.6	432	406
24 x 12	610	323.9	432	397
24 x 10	610	273.1	432	384

5 Key Tips During Procurement

1. ASME B16.9 is not the same as wall thickness standard

The wall thickness of the tee is determined by the schedule of the steel pipe it is fitted with (Sch 20 / 40 / 80 / XS / XXS).

2. The default port for a tee is a butt weld bevel (BW)

The common bevel angle is 37.5° (ASME B16.25).

3. Reducing tee ≠ Reducer + Straight tee

It offers superior strength and fluid performance, and is more commonly used in oil and gas projects.

4. For large diameters (≥24″)

Pay attention to manufacturing tolerances and delivery time.

They are usually hot-pressed or molded.

5. Common material and standard combinations

ASTM A234 WPB → Carbon steel tee

ASTM A403 WP304/316 → Stainless steel tee

ASTM A420 WPL6 → Low-temperature tee

FAQ

1. Can ASME B16.9 tees be used in high-pressure systems?

Yes, provided the material, wall thickness, and design pressure meet ASME B31.3 / B31.4 / B31.8 requirements.

2. What is the difference between ASME B16.9 and MSS SP-75?

SP-75 is mainly used for high-strength, large-diameter oil and gas pipelines, while B16.9 is more universal.

3. Can non-standard tee sizes be customized?

Yes, but it must be specified as "Non-standard" and drawings must be provided for confirmation.

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