Equal & reducing | EN 10253-2 and EN 10253-4 | DN 15 – DN 1200
A Type B tee to EN 10253-2 or EN 10253-4 is designed to carry the full service pressure of the connecting pipe of the same material and wall thickness. To do that, the tee body is made thicker than the pipe where the branch opening weakens it, while the ends are machined to the wall of your pipe so they weld straight on. Type B is our specialism: we make equal and reducing Type B tees in non-alloy, CrMo, stainless and duplex grades for European PED projects, with EN 10204 3.1 or 3.2 documents.
| Standard | EN 10253-2 (non-alloy, ferritic), EN 10253-4 (austenitic, duplex) |
| Type | Type B (Type A also available) |
| Shapes | Equal and reducing tees |
| Size | DN 15 – DN 1200 |
| Body wall | Increased to the standard for full pressure |
| Ends | Machined to your pipe wall and bore |
| Documents | EN 10204 3.1 std, 3.2 on request |
| Item | Type A tee | Type B tee |
|---|---|---|
| Pressure capacity | Reduced pressure factor: weaker than the straight pipe of the same wall | Full service pressure of the connecting pipe |
| Body wall | Same nominal wall as the pipe | Thicker body (run and branch) as required by the standard |
| Ends | Pipe wall | Machined or tapered to the pipe wall for welding |
| Piping design | Designer must allow for the reduced factor | Can be treated like the connecting pipe |
| Typical use | Low-stress utility lines | Steam, boiler, process and PED piping at full design pressure |
EN 10253 does not link Type A or Type B to a PED category. The piping designer chooses the type. What matters is that the tee supplied matches the type and wall used in the design, and that the order says “EN 10253-2 Type B” or “EN 10253-4 Type B”, not just “EN 10253”.
For a reducing tee, the run and branch body thicknesses are both checked against the standard. Use our free Type B thickness check to compare a tee you have been offered with the requirement, or read the Type A vs Type B guide.
P235GH (1.0345), P265GH (1.0425), P355N, P275NL1 / P355NL1 for low temperature
16Mo3 (1.5415), 13CrMo4-5 (1.7335), 10CrMo9-10 (1.7380), X10CrMoVNb9-1 / P91 (1.4903)
1.4307, 1.4404, 1.4571, 1.4541, 1.4462 duplex, 1.4410 super duplex
It is a buttweld tee made to EN 10253-2 or EN 10253-4 that can carry the full service pressure of the connecting pipe of the same material and wall thickness. To achieve this the tee body is usually thicker than the pipe, and the ends are machined to the pipe wall.
Not automatically. EN 10253 does not tie Type A or Type B to a PED category; the piping designer chooses. Type B is used when the tee must work at the full design pressure of the pipe wall. The tee supplied must match the type used in the design.
The branch opening removes metal from the run, so the body around it needs extra thickness to keep full pressure capacity. A Type B tee therefore has a thicker body than a Type A tee for the same pipe, while the welding ends match the pipe wall.
Yes. We make equal and reducing Type B tees. For a reducing tee both the run and branch body thicknesses are designed to the standard, and both ends are matched to their connecting pipes.
Non-alloy grades such as P235GH and P265GH, CrMo grades such as 16Mo3, 13CrMo4-5, 10CrMo9-10 and P91 to EN 10253-2, and stainless and duplex grades such as 1.4404, 1.4571 and 1.4462 to EN 10253-4.
Reply from our Mumbai sales office, usually within one working day. You can attach drawings by email to marketing@arshyafittings.com.
