ASME B16.9 | Reducing / Unequal Tees | Butt-Welding Pipe Fittings | Carbon Steel, Stainless Steel, Duplex, Alloy & Nickel Alloys
Elite Buttweld Reducing Tees, also known as Unequal Tees, are factory-made pipe fittings used to create a 90° branch connection where the branch outlet is smaller than the main run. They provide a practical transition from a larger pipeline to a smaller branch while maintaining a compact and robust welded connection.
Elite supplies Reducing Tees in seamless, welded and fabricated construction, with carbon steel, stainless steel, duplex, alloy steel, nickel alloy and other materials available according to applicable standards and project requirements.
| Parameter | Specification |
|---|---|
| Manufacturer | Elite |
| Product | Buttweld Reducing Tee / Unequal Tee |
| Primary Standard | ASME B16.9 |
| Configuration | Reducing / Unequal Tee |
| Branch Angle | 90° |
| Size Range | NPS 1/2"–48" |
| Run Size | As specified |
| Branch Size | Smaller than run size |
| Construction | Seamless / Welded / Fabricated |
| End Connection | Butt Weld |
| Wall Thickness | SCH 5S, 10S, 20, 40S, STD, 80S, XS, 100, 120, 140, 160, XXS and custom |
| Dimensions | ASME B16.9 where applicable |
| End Preparation | ASME B16.25 where applicable |
| Material Standards | ASTM / ASME applicable specifications |
| Heat Treatment | According to material and applicable specification |
| Surface Finish | Pickled / Blasted / Polished / Coated / Project Specified |
| Inspection | Visual, dimensional, PMI, UT, RT, MT, PT, hardness and other NDE as specified |
| Documentation | MTC, EN 10204 3.1/3.2, inspection reports and project documentation |
| Configuration | Description | |
|---|---|---|
| Reducing Tee | Smaller branch outlet than the main run | |
| Unequal Tee | Alternative designation for a reducing tee | |
| Seamless Reducing Tee | Seamless construction for applicable sizes/materials | |
| Welded Reducing Tee | Welded construction for selected sizes/materials | |
| Fabricated Reducing Tee | Custom large-diameter or special construction | |
| Note: An Equal Tee has the same run and branch size. A Reducing Tee has a smaller branch size and should be specified as run × branch size. | ||
ASME B16.9
Primary dimensional standard for factory-made wrought buttwelding fittings, including reducing tees.
ASME B16.25
Butt-welding end preparation.
ASTM / ASME Material Specifications
Applicable material standards according to the selected material and grade.
ASME B31.3 / B31.1
Process and power piping requirements, where applicable.
NACE MR0175 / ISO 15156
For sour-service applications when specifically required by the project.
ASME Section II
Material requirements where applicable to pressure equipment and project specifications.
Note: ASME B16.28 should not be listed as the primary standard for Reducing Tees. Current applicable tee dimensions are covered by ASME B16.9.
Carbon Steel
ASTM A234 WPB, WPC and applicable WPHY grades including WPHY 42, WPHY 46, WPHY 52, WPHY 60, WPHY 65 and WPHY 70.
Low Temperature Carbon Steel
ASTM A420 WPL3, WPL6 and other applicable grades.
Stainless Steel
ASTM A403 WP304/304L, WP316/316L, WP321/321H, WP347/347H and other applicable grades.
Duplex & Super Duplex
ASTM A815 grades including UNS S31803, S32205, S32750 and S32760.
Alloy Steel
ASTM A234 WP1, WP5, WP9, WP11, WP12, WP22 and WP91.
Nickel Alloys
ASTM B366 and applicable specifications for Nickel 200/201, Monel 400/K500, Inconel 600/601/625/800/825, Hastelloy C276 and Alloy 20.
Copper-Nickel Alloys
Applicable Cu-Ni grades including UNS C70600 and C71500.
Titanium
Applicable titanium grades manufactured to the relevant ASTM specification, including ASTM B363 where applicable.
Material selection is based on operating pressure, temperature, process fluid, corrosion conditions, mechanical requirements and applicable project specifications.
Standard Reducing Tee
The main run is larger than the branch outlet, providing a 90° connection to a smaller pipeline.
Concentric Reducing Tee
The branch is centrally aligned with the run where the required geometry and project design call for a concentric configuration.
Seamless Reducing Tee
Seamless construction for applicable sizes, materials and wall thicknesses.
Welded Reducing Tee
Welded construction for selected sizes and materials where permitted by the applicable specification.
Fabricated Reducing Tee
Custom-fabricated construction for large diameters, special dimensions or project-specific requirements.
Standard Reducing Tee dimensions are manufactured in accordance with ASME B16.9, where applicable.
Available wall thicknesses include:
SCH 5S, 10S, 20, 40S, STD, 80S, XS, 100, 120, 140, 160 and XXS, together with project-specific wall thicknesses.
Ordering dimensions should identify both the run size and branch size, for example:
6″ × 4″ Reducing Tee
12″ × 8″ Reducing Tee
24″ × 16″ Reducing Tee
For large-diameter, heavy-wall or fabricated Reducing Tees, dimensions can be manufactured according to approved engineering drawings.
Elite Reducing Tees are manufactured using suitable forming, welding and fabrication processes according to material, size and project requirements.
Quality control can include:
Elite can manufacture Reducing Tees according to customer drawings, piping isometrics and project specifications, including:
Depending on project requirements, supply can include:
Elite Buttweld Reducing Tees are used in:
Reducing Tees are particularly suitable where a smaller branch line needs to be connected to a larger main pipeline.
When ordering Buttweld Reducing Tees, please specify:
| Item | Required Information |
| Product | Buttweld Reducing Tee / Unequal Tee |
| Run Size | NPS |
| Branch Size | NPS |
| Material & Grade | ASTM / ASME specified grade |
| Wall Thickness | Schedule or actual thickness |
| Construction | Seamless / Welded / Fabricated |
| Standard | ASME B16.9 or project specified |
| End Preparation | ASME B16.25 or project specified |
| Surface Finish | Standard / Pickled / Blasted / Polished / Coated |
| Inspection | PMI / UT / RT / MT / PT / Hardness etc. |
| Documentation | EN 10204 3.1 / 3.2 and project documents |
| Quantity | Required quantity |
| Special Requirements | Drawing, coating, NACE, testing or other project requirements |
Typical Order Example:
6″ × 4″ Reducing Tee, ASME B16.9, ASTM A234 WPB, SCH 40, Seamless, ASME B16.25 Bevel Ends, EN 10204 3.1, PMI.
