Tees

Tees are pipe fittings used to distribute the flow of liquids or gases. They are T-shaped connectors with three openings: one connects to the main pipeline, and the other two connect to its branches. 

Tee Classification by Design

Tees are divided into two main types based on the diameter of their openings:

Straight Tees (Equal-Diameter Tees)

• All three openings have the same diameter.
• Used to connect pipes of the same cross-section.
• Applied when uniform flow distribution of the working medium is required.

Reducing Tees

• The side branch opening has a different diameter than the other two.
• Allow connection of pipes with different diameters.
• Used to adjust pressure or flow velocity of the working medium.

Tee Classification by Material

The material of a tee is selected based on operating conditions (temperature, pressure) and the type of transported medium (aggressive or neutral). Common materials include:

Metal Tees

• Steel: Carbon steel, stainless steel.
  • Used in industrial systems.
  • Stainless steel tees are suitable for aggressive environments (chemical industry) and food production.
• Cast Iron: Used in low-pressure and low-temperature systems.

Polymer Tees

• PVC (Polyvinyl Chloride): Lightweight and corrosion-resistant; used in sewage systems.
• Polypropylene: Used for water supply and heating systems.
• Polyethylene: Commonly used in irrigation systems.

GOST 17376-2001

GOST 17376-2001 regulates production of seamless welded tees made of carbon and low-alloy steel. This standard aligns with the international ISO 3419-81. It covers two main types of tees: straight (equal-diameter) and reducing.