Stamped Tee

What is a Stamped Tee?

A stamped tee is a branch fitting made by pressing or stamping a branch opening directly into a section of pipe, then welding a short branch neck to the opening. Unlike a fully forged tee, a stamped tee is formed from pipe or plate, making it a cost-effective option for lower pressure and non-critical service. It provides a branch connection where a forged tee would be over-specified.

Standards and Specifications

Stamped tees are manufactured to MSS SP-97 and ASME B16.9, with branch reinforcement per ASME B31.3. They are available in sizes from NPS 2 by NPS 1 to NPS 48 by NPS 24, with wall thicknesses matching the run pipe. The branch neck is beveled for welding. Stamped tees may be used where the branch opening meets the reinforcement requirements of the piping code.

Materials and Grades

Carbon steel A234 WPB and A105 are standard for general service. Stainless steel 304/304L and 316/316L provide corrosion resistance for water and chemical applications. The run pipe and branch neck material should match for compatible welding. Material is traceable by heat number and supplied with mill certificates.

Pressure and Design Considerations

Stamped tees are typically rated for lower pressure classes compared with forged tees, suitable for Class 150 and Class 300 service. The branch opening reinforcement is calculated per ASME B31.3, with either the integral pipe wall providing reinforcement or an external reinforcement pad added. Each tee is hydrostatically tested.

Applications

Stamped tees are used in water supply, HVAC, compressed air, lubrication, fire protection, and general utility piping. They provide branch connections for drains, vents, instrument take-offs, and small branch lines in low to medium pressure systems where economy and quick delivery are priorities.

Advantages

Stamped tees are more economical than forged tees, especially for large sizes where forging would be expensive. They are lighter and easier to handle. The stamped branch can be positioned on the pipe run as needed. They provide a reliable branch connection for non-critical service without the cost of a fully forged fitting.

Installation Guidelines

Cut or stamp the branch opening in the run pipe to the specified diameter. Weld the branch neck to the opening using a full-penetration fillet or groove weld. If a reinforcement pad is required, weld it around the branch. Radiographic or magnetic particle inspection verifies weld quality. Pressure test the completed joint.

Quality Assurance

Each stamped tee is marked with size, grade, heat number, and manufacturer's identification. Inspection includes dimensional checks, visual examination, and NDE when specified. Material test certificates are provided. Fittings are coated with rust-preventive oil and packaged for export.