A Steel tee is a pipeline fitting (part of the pipeline structure) with three connector ends designed to connect side pipe branches to the main line (in addition the flow changes its direction at an angle of 90°).
Straight tees in pipeline structures are used in heating systems, cold and hot water supply systems of steam systems as well as plants of the oil, gas and chemical industry, etc. Tees are manufactured from carbon and low-alloy steels, heat and corrosion-resistant steel grades 15Х5М, 12Х18Н10Т, 10Х17Н13М2Т.
Welded tees - manufacturing methods:
- casting into molds
- hot stamping of a single-piece forging blank including drilling of holes
- gas cutting of parts with welding
- die forging from round bars and sheets followed by machining, etc.
Depending on the manufacturing method, straight tees are divided into: seamless, welded, turned, and stamped and welded tees. For manufacturing stamped and welded tees as per TU102-488-95, steel of the following grades is used: 20; 09Г2С; 12Х18Н10Т. They are operated under pressure up to 2.5 MPa and at temperature varying from -30°С to +300°С.
Welded tees with a weld in the neck as per GOST 17376-2001 are manufactured from the following steel grades: 20; 09Г2С; 12Х18Н10Т. Steel tee with cover plates manufactured pursuant to (Technical Specification) TU 51-29-81 is intended for the regions of the Far North.
Seamless tees as per GOST 17376-2001 are manufactured from the following steel grades: 20; 09Г2С; 12Х18Н10Т. These pipeline elements withstand pressures up to 16 MPa and may be operated at ambient temperatures varying from -70°С to +450°С.
Two types of tees are distinguished: straight and reduced tees
- All outlets of straight welded tees have the same diameter.
- Outlets of reduced tees have different diameters.
Sample conventional notation: