Pipe Tee

What is a Pipe Tee?

A pipe tee is a T-shaped fitting used to branch a pipe run at 90 degrees, available in equal and reducing configurations. It is one of the most common fittings in industrial piping, allowing flow to be split, combined, or routed to a branch line. Pipe tees are manufactured in a wide range of materials, sizes, and pressure ratings to suit virtually any piping application.

Standards and Specifications

Pipe tees are manufactured to ASME B16.9 and ASME B16.28, conforming to MSS SP-75 and ASTM A234. Equal tees have all ends the same size; reducing tees have a smaller branch. Sizes range from NPS 1/8 to NPS 48, with wall schedules from SCH 10 to SCH XXS. Socket weld and threaded ends are also available for small-bore high-pressure service per ASME B16.11.

Materials and Grades

Carbon steel A234 WPB and A105 are standard for oil, gas, water, and steam. Stainless steel 304/304L and 316/316L provide corrosion resistance for chemical, food, and marine applications. Alloy steel WP11, WP22, and WP91 handle high-temperature refinery and power service. Low-temperature A420 WPL6 serves cryogenic systems. All material is traceable by heat number.

Pressure and Temperature Ratings

Pipe tees are rated for pressure classes 150 through 2500. The branch junction is reinforced by the tee geometry, with wall thickness designed per ASME B31.3. Temperature range depends on material: carbon steel to 425 degrees Celsius, alloy steel to 600 degrees Celsius, stainless steel from cryogenic to 800 degrees Celsius. Each tee is hydrostatically tested.

Applications

Pipe tees are used in refineries, petrochemical plants, oil and gas production, chemical processing, power generation, water treatment, HVAC, fire protection, and general industrial piping. They create branch connections for instruments, safety valves, drains, vents, sampling points, and utility take-offs from process headers.

Advantages

Pipe tees provide a reliable, code-compliant branch connection in a single fitting. Butt-welded tees create permanent, leak-free joints. Standard dimensions ensure interchangeability. The wide range of materials, sizes, and pressure ratings means a tee is available for virtually any piping specification.

Installation Guidelines

Bevel all ends for butt-welded tees, or prepare socket/thread ends accordingly. Align the tee with the run and branch, tack weld, and complete full-penetration welds with matching filler metal. Apply preheat and post-weld heat treatment as required. Radiographic inspection verifies weld integrity. Provide support near the branch.

Quality Assurance

Each pipe tee is marked with size, grade, heat number, wall thickness, and manufacturer's stamp. Inspection includes dimensional checks, wall thickness verification, visual examination, and NDE when specified. Material test certificates to EN 10204 3.1 are provided. Tees are coated with rust-preventive oil and ends are protected for shipping.