ASME B16.9 Butt Weld Tee

ASME B16.9 butt weld tee is widely used in industrial pipeline systems, occupying a place in industrial pipeline construction with strict production standards, diverse product types, and advanced production processes.

What is ASME B16.9 Standard

ASME B16.9 is a manufacturing standard for forged steel butt welded pipe fittings developed by the American Society of Mechanical Engineers (ASME). This standard has a high degree of recognition and authority worldwide, providing a unified and standardized technical basis for the design, production, inspection, and other aspects of welded pipe fittings.

The ASME B16.9 standard covers a wide range of products, mainly including various specifications of ASME B16.9 butt weld tee, elbows reducers, caps,etc. The size range of these fittings is from 1/2” (12.7 mm) to 48” (1219.2 mm), which can meet the needs of different piping systems.

Specification of ASME B16.9 BW Tee

ASME B16.9 standard covers multiple key elements in the manufacturing of butt weld fittings. In terms of dimensional tolerances, the allowable deviations for the outer diameter, inner diameter, wall thickness, length, angle, and other dimensions of welded pipe fittings are clearly defined to ensure that the fittings can be accurately matched with other components in the pipeline system, ensuring the sealing and stability of the connection.

Shape Type	Equal Tee and Reducing Tee
Size Range	1/2" - 48" / DN15 - DN1200
Thickness Schedule	SCH 10 - SCH 160, XXS
Standard	ANSI / ASME B16.9, MSS SP 43, JIS B2311/2312/2313, DIN2605/2615/2616/2617, EN10253
Carbon Steel	ASTM A234 WPB/WPC, A420 WPL6
API 5L Grades	ASTM A860 WPHY 42 / 46 / 56 / 60 / 65
Alloy Steel	ASTM A234 WP11 / WP12 / WP 5 / WP9 / WP91 / WP92,15CrMoG, 12Cr1MoVG, 12Cr5Mo, 1Cr5Mo, Cr9Mo, 10CrMo910, 12CrMo4-5
Stainless Steel	ASTM A403 WP304/304L/304H, 316/316L, 310S, 317,347, 904L, A815 S32205, S31803, 32750, 32760

Dimension ASME B16.9 Butt Weld Tee

Nominal Size		Outside Diameter at Bevel	Center to End
DN	NPS	OD1×OD2	C	M
15	1/2	21.3	25	25
20	3/4	26.7	29	29
25	1	33.4	38	38
32	11/4	42.2	48	48
40	11/2	48.3	57	57
50	2	60.3	64	64
65	21/2	73.0	76	76
80	3	88.9	86	86
90	31/2	101.6	95	95
100	4	114.3	105	105
125	5	141.3	124	124
150	6	168.3	143	143
200	8	219.1	178	178
250	10	273.0	216	216
300	12	323.8	254	254
350	14	355.6	279	279
400	16	406.4	305	305
450	18	457.0	343	343
500	20	508.0	381	381
550	22	559.0	419	419
600	24	610.0	432	432
650	26	660.0	495	495
700	28	711.0	521	521
750	30	762.0	559	559
800	32	813.0	597	597
850	34	864.0	635	635
900	36	914.0	673	673
950	38	965.0	711	711
1000	40	1016.0	749	749
1050	42	1067.0	762	711
1100	44	1118.0	813	762
1150	46	1168.0	851	800
1200	48	1219.0	889	838

Tolerance of Butt Weld Fittings

Nominal  Size		All Fittings		45°&90° Elbows & Tees, Crosses	3D Radius Elbows	Returns			Caps	Reducers & Lap Joint Stub Ends	Lap Joint  Stub Ends
DN	NPS	OD 3) 4)	ID 3)	A   B   C   M	A   B	O	K	U	E,  E1	H   F	G	R	t
15-65	1/2 -21/2	+1.6 -0.8	± 0.8	± 2	± 3	± 6	± 6	±  1	± 3	± 2	0    -1	0    -1	+1.6 0
80-90	3-31/2	± 1.6	± 1.6	± 2	± 3	± 6	± 6	±  1	± 3	± 2	0    -1	0    -1	+1.6 0
100	4	± 1.6	± 1.6	± 2	± 3	± 6	± 6	±  1	± 3	± 2	0    -1	0    -2	+1.6 0
125-200	5-8	+2.4 -1.6	± 1.6	± 2	± 3	± 6	± 6	±  1	± 6	± 2	0    -1	0    -2	+1.6 0
250-450	10-18	+4.0 -3.2	± 3.2	± 2	± 3	± 10	± 6	± 2	± 6	± 2	0    -2	0    -2	+3.2 0
500-600	20-24	+6.4 -4.8	± 4.8	± 2	± 3	± 10	± 6	± 2	± 6	± 2	0    -2	0    -2	+3.2 0
650-750	26-30	+6.4 -4.8	± 4.8	± 3	± 6	---	---	---	± 10	± 5	---	---	---
800-1200	32-48	+6.4 -4.8	± 4.8	± 5	± 6	---	---	---	± 10	± 5	---	---	---
1300-1500	52-60	+6.4 -4.8	± 4.8	± 5	---	---	---	---	---	---	---	---	---
1600-1700	64-68	+6.4 -4.8	± 4.8	± 5	---	---	---	---	---	---	---	---	---
1800-2000	72-80	+6.4 -4.8	± 4.8	± 5	---	---	---	---	---	---	---	---	---

ASME B16.9 standard also specifies requirements for the surface quality and pressure testing of pipe fittings. In terms of surface quality, the inner and outer surfaces of the pipe fittings should be smooth and free from defects such as cracks, folds, scratches, etc; Pressure testing requires pipe fittings to undergo hydrostatic or pneumatic testing at a specified pressure to verify their sealing and pressure resistance performance, ensuring that there will be no leakage or other issues during use.

Types of Butt Weld Tee

ASME B16.9 butt weld tee can be classified into various types according to different classification methods. According to material classification, there are mainly carbon steel, alloy steel, and stainless steel.

Carbon Steel BW Tee

Carbon steel materials have good toughness and weldability, and are relatively inexpensive. They are suitable for general industrial pipeline systems, such as pipelines transporting media such as water, steam, and oil.

Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Cr	Mo	Ni	Cu	Cb	V
ASTM A234 WPB	MIN		0.29			0.10
	MAX	0.30	1.06	0.050	0.058		0.40	0.15	0.40	0.40	/	0.08
ASTM A420 WPL6	MIN		0.50			0.15
	MAX	0.30	1.35	0.035	0.040	0.40	0.40	0.30	0.12	0.40	0.02	0.08

Mechanical Properties

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %	HARDNESS
ASTM A234 WPB	415 min	240 min	22 min	197 max
ASTM A420 WPL6	415-655	240 min	30min

Alloy Steel ASME B16.9 Tee

Alloy steel materials improve the strength, hardness, corrosion resistance, and other properties of welded tees by adding alloying elements such as chromium, nickel, and molybdenum. They are suitable for high-pressure, high-temperature, and highly corrosive working environments, such as high-pressure hydrogenation pipelines in the petrochemical industry and high-temperature steam pipelines in the power industry;

Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Cr	Mo
ASTM A234 WP12	MIN	0.050	0.30				0.80	0.440
	MAX	0.200	0.80	0.045	0.045	0.60	1.25	0.650
ASTM A234 WP11 CL1	MIN	0.050	0.30			0.50	1.00	0.440
	MAX	0.150	0.60	0.030	0.030	1.00	1.50	0.660
ASTM A234 WP22 CL1,CL3	MIN	0.050	0.30				1.90	0.870
	MAX	0.150	0.60	0.040	0.040	0.50	2.60	1.130

Mechanical Properties

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %
ASTM A234 WP11 CL1	415 min	205 min	30min
ASTM A234 WP12 CL1	415 min	220min	30min
ASTM A234 WP12 CL2	485 min	275 min	30min
ASTM A234 WP22 CL1	415 min	205 min	30min
ASTM A234 WP22 CL3	520min	310min	30min

Stainless Steel Butt Weld Tee

Stainless steel butt weld tee have excellent corrosion resistance and beautiful surfaces, suitable for pipelines transporting corrosive media, such as acid and alkali solution pipelines in the chemical industry and sanitary grade pipelines in the food and pharmaceutical industry.

Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Ni	Cr
ASTM A403 WP304	MIN						8.0	18.0
	MAX	0.08	2.00	0.045	0.030	1.00	11.0	20.0
ASTM A403 WP304L	MIN						8.0	18.0
	MAX	0.03	2.00	0.045	0.030	1.00	11.0	20.0

Mechanical Properties

MATERIAL	ASTM A403 WP304	ASTM A403 WP304L
T.S (MPA)	515 min	485 min
Y.S (MPA)	205 min	170 min
EL %	28 min	28 min

According to the ratio of the diameter of the branch pipe to the main pipe, ASME B16.9 butt weld tee can be divided into equal diameter tees and reducing diameter tees.

The three openings of the equal diameter tee have the same diameter and are suitable for connecting three pipes of the same diameter to achieve equal diameter diversion or merging of media;

The three principles of reducing diameter refer to the different diameters of branch pipes and main pipes, which can meet the connection requirements between pipes of different diameters, achieve variable diameter diversion or merging of media in the pipeline system, and improve the flexibility and adaptability of the pipeline system.

Manufacturing Process

The manufacturing process of ASME B16.9 butt weld tee is complex and rigorous, mainly including the following key steps:

Raw Materials

According to the material requirements of the product, select high-quality steel that meets the ASME B16.9 standard as the raw material. Raw materials need to undergo strict inspections, including chemical composition analysis, mechanical property testing, etc., to ensure that their quality meets standard requirements. Only qualified raw materials can enter the subsequent production process, ensuring product quality from the source.

Forming

By hydraulic bulging, the middle part of a pipe with the same diameter as the three-way main pipe is placed into a hydraulic forming mold. Ultra high pressure liquid is injected into the pipe blank, and axial thrust is applied at both ends of the pipe blank to replenish the material. Under the combined action of liquid pressure and axial thrust, the metal of the tube blank flows towards the mold cavity (branch direction), ultimately forming a three-way blank. The three-way blank still needs to undergo preliminary cleaning to remove surface oxide scale and impurities.

Heat Treatment

In order to eliminate the internal stress generated during the forging process and improve the mechanical properties of the tee, it is necessary to perform heat treatment on the forged tee blank. The heat treatment process depends on different materials and usually includes three stages: heating, insulation, and cooling. During the heat treatment process, it is necessary to precisely control the heating temperature, holding time, and cooling rate to ensure that the tee can achieve the expected mechanical performance indicators, such as hardness, strength, toughness, etc.

Machining

After heat treatment, the three-way blank needs to be machined to meet the size and accuracy requirements specified by the standard. Mechanical processing mainly includes turning, milling, drilling and other processes, through which the various openings, end faces, inner and outer surfaces of the tee are machined to ensure that the dimensional tolerances and surface roughness of the tee comply with the provisions of ASME B16.9 standard.

Inspection and Testing

Inspection and testing are carried out throughout the production process of ASME B16.9 butt welded tees. In addition to raw material inspection, intermediate inspection during forging process, performance inspection after heat treatment, and dimensional inspection after mechanical processing, finished products also need to undergo final inspection and testing, including appearance inspection, dimensional review, pressure testing, non-destructive testing, etc.

Advantages

ASME B16.9 butt weld tee have many significant characteristics.

Firstly, reliable quality is one of its core characteristics. Due to strict adherence to ASME B16.9 standards in production and manufacturing, there are strict specifications and requirements for the selection of raw materials, control of production processes, and inspection and testing of products, ensuring that every product meets high-quality standards and can operate stably in various harsh working environments, reducing the risk of pipeline system failures.

Secondly, it has excellent performance. ASME B16.9 butt weld tee have high strength and stiffness, can withstand significant pressure and temperature changes, and are not easily deformed or damaged during long-term use. At the same time, its good sealing performance can effectively prevent medium leakage, ensure the safe operation of pipeline systems, and reduce economic losses and environmental hazards caused by leakage.

In addition, it has strong universality. The butt welded tee specifications under this standard are complete and can meet the needs of different pipeline systems. It has been widely recognized and applied worldwide, facilitating cooperation and communication in pipeline engineering between different countries and regions, and reducing the troubles and costs caused by inconsistent standards.

Scope of Application

ASME B16.9 butt weld tee have a wide range of applications due to their excellent performance and reliable quality, covering multiple important industries:

Petrochemical Industry

Power and Energy Industry

Metallurgical Industry

Shipbuilding Industry

Urban Infrastructure Construction