Knowledge sharing of stainless steel tees

The following is a comprehensive knowledge sharing of stainless steel tees, covering classification, characteristics, applications and selection points:

1. Overview of stainless steel tees

Stainless steel tees are pipe fittings used for diversion or convergence in pipeline systems. According to the interface form, they are divided into equal-diameter tees (three ports with the same diameter) and reducing tees (one port with different diameters). The materials are mainly 304, 316, and 316L, with the characteristics of corrosion resistance, high pressure resistance, and long life.

2. Main classification

According to the manufacturing process

Welded tees: welded from steel pipes, low cost, suitable for low-pressure scenarios.

Seamless tees: integral forging and forming, strong pressure bearing capacity, used in high-pressure/high-purity systems (such as chemicals and medicine).

Hydraulic expansion tee: formed by hydraulic expansion, uniform wall thickness, and low flow resistance.

According to the connection method

Butt welding (BW): welding connection, good sealing, used for high-temperature and high-pressure pipelines.

Socket welding (SW): pipe inserted into the tee welding, easy installation.

Threaded (TH): threaded connection, easy to disassemble, suitable for small-diameter pipelines.

Flange type: fixed by bolts, commonly used in large-diameter pipelines.

By branch angle

45° tee: gentle diversion angle, reducing turbulence.

90° tee: right-angle diversion, small space occupation.

III. Core features

Corrosion resistance: 316L contains molybdenum, resistant to chloride ion corrosion, suitable for seawater and chemical transportation.

High strength: stainless steel can withstand pressure above 16MPa (depending on wall thickness).

Sanitary: smooth surface without dead corners, in line with food grade (GB4806.1) and medical standards.

Temperature adaptability: -196℃~800℃ (austenitic stainless steel).

IV. Application areas

Petrochemical: resistant to acid and alkaline media (such as 316L for sulfur-containing oil and gas).

Food and beverage: 304 material meets hygiene requirements and is used for dairy and beer pipelines.

Pharmaceutical industry: purified water and water for injection systems under sterile environment.

Shipbuilding: 316 tee is resistant to seawater corrosion.

Nuclear power energy: Ultra-thick wall tees are used for high-pressure steam pipelines.

V. Key parameters for selection

Material

304: General type, suitable for weak corrosion environment.

316/316L: Contains molybdenum, pitting resistance, used in acidic and salt spray environments.

904L: High corrosion resistance, used for strong acids such as sulfuric acid and phosphoric acid.

Pressure level

Reference standard: ANSI B16.9 (American standard), GB/T 12459 (national standard).

Common grades: Sch10, Sch40, Sch80 (the larger the value, the thicker the wall thickness).

Size standard

Diameter range: DN15~DN1200 (or 1/2"~48").

End surface treatment: groove (welding), thread accuracy (imperial/metric).

Certification requirements

Food grade: FDA, EC1935.

Industrial certification: ISO9001, PED (EU Pressure Equipment Directive).

VI. Installation and maintenance precautions

Welding process: Use argon arc welding (TIG) to reduce oxidation, and pickling and passivation treatment is required after welding.

Flow direction design: Branch pipelines need to consider fluid resistance and avoid sharp turns at right angles.

Regular inspection: Chloride ion environment needs to detect stress corrosion cracking (SCC).

Seal test: After installation, a pressure test of 1.5 times the working pressure is required.

VII. Common problems

Question 1: Is the tee branch prone to leakage?

Countermeasures: Choose seamless tees or increase the height of the weld feet to avoid cold welding.

Question 2: Is the stainless steel tee rusting?

Countermeasures: Confirm whether the material meets the standard (such as the Ni content of 304 ≥8%) to avoid contact with carbon steel to cause electrochemical corrosion.

VIII. Mainstream market standards

International: ASTM A403 (American standard), DIN 2605 (German standard).

Domestic: GB/T 12459-2017, HG/T 21635 (Ministry of Chemical Industry Standard).

Cangzhou Aosendik Pipe Fittings Manufacturing Co., Ltd. is a large manufacturer specializing in the production of elbows, tees, reducers, elbows and caps. We can implement ASTM, ANSI, JIS, DIN, GB and other standards, basically covering all types of steel.

If you have any purchasing needs or questions, please contact us.

Mobile: 86-13668807131

Website: https://www.authenticfitting.com/

Address: Mengcun Hui Autonomous County, Cangzhou City, Hebei Province

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