A tee is named by its run size first and branch size second: a 6 x 6 tee is equal, a 6 x 4 tee reduces at the branch. The branch outlet is the structurally hardest part of any fitting — it is formed by pulling or pressing the branch out of the run wall, then sizing and bevelling all three ends. Getting that crotch area right, at full wall thickness, is what separates a pressure-rated tee from a fabrication.
Crosses (four-way fittings) are the four-outlet form of the same fitting family, used on instrument and utility manifolds.
| Item | Range / Options |
|---|---|
| Types | Equal tees (catalogue executions) |
| Standards | ASME B16.9 (catalogue tee records) |
| Size range | Confirmed per product at enquiry — catalogue executions: seamless equal tees in A234 WPB, Sch 80 and Sch 160 |
| Wall thickness | Ordered to the run and branch schedules of your line — state both on the enquiry |
| Materials | ASTM A234 WPB in the executions above, including the NACE execution; further grades are assessed against your enquiry for the specific product |
| Options | NACE executions (SSC Region 3 + HIC, per the catalogue tee records) listed for sour service — confirm on enquiry |
Equal or Reducing?
If the branch line keeps the run size, an equal tee is the fitting. If the branch steps down — the common case for take-offs to equipment, vents, drains and instruments — a reducing tee does it in one piece, without a separate reducer and an extra weld. Reducing tees are ordered as run size x branch size, each with its own schedule where they differ: the branch outlet is formed and bevelled for its own line, not assumed to follow the run wall.
Heavy-Wall and Sour Service
Tees are often the highest-stressed item on a line list. The catalogue includes heavy-wall executions such as Schedule 160 in A234 WPB for high-pressure runs, and NACE tee executions (SSC Region 3 and HIC tested) for sour oil and gas service — state the sour-service requirement explicitly on the enquiry so the correct execution is quoted.
Matching the Rest of the Line
A tee order usually travels with elbows and reducers in the same grade and schedule set. Send the whole line list with the enquiry: the grade and schedule of each item are assessed and confirmed for the specific product before order, and the packing is agreed item by item at quotation.
Frequently Asked Questions
How do I specify a reducing tee?
A reducing tee is specified by run size, then branch size, then the schedule for each — for example 8 x 6, Schedule 80 run / Schedule 80 branch. The catalogue executions on this site are equal tees; state a reducing requirement on the enquiry and it will be assessed for the specific product before order.
Do you supply tees for sour (NACE) service?
The catalogue includes A234 WPB tee executions listed to NACE, with SSC Region 3 and HIC requirements. Mark the requirement on your enquiry; it changes the material route and testing, so it must be agreed at quotation stage.
Can tees be supplied in stainless steel?
The catalogue tee executions on this site are carbon steel A234 WPB. If your specification calls for a stainless tee, name the grade on the enquiry and it will be assessed for the specific product before order. The stainless steel fittings page gives the family overview.
Related Products
Butt Weld Elbows
Elbow executions in A234 WPB and A403 WP304L, each listed on its own page.
Send Your Specification
Tell us the size, schedule or pressure class, material grade and quantity for the butt weld tees you need. MOQ and lead time are confirmed in the quotation for your exact specification.