When a drawing calls up ASME B16.9, it is fixing the geometry of the joint: centre-to-end dimensions of elbows and tees, face-to-face lengths of reducers and caps, outside diameters at the bevel, wall tolerances and the marking each fitting must carry. Two B16.9 fittings from two different makers fit the same line because the standard leaves no room for house styles. Two things must be kept apart on this page. As general standard knowledge, B16.9 sits alongside companion standards: B16.25 for the weld bevel details at fitting ends. Short-radius elbows and returns were the province of B16.28 in earlier editions of the series; current editions of B16.9 have absorbed them. That is what those standards cover, whoever makes the fitting. Separately, the ASME B16.9 catalogue records on this site are the ones named on the elbow, tee and reducer pages; the cap, stub end and pipe bend pages state the patterns recorded for their own types, which are not B16.9 records. Compliance for a specific product is confirmed against your specification before order.
Pressure design under B16.9 is tied to the pipe: a fitting made from a given material grade and marked for a given schedule is designed to be used with pipe of the same grade and schedule, whose allowable stresses come from the piping code. That is why fittings are ordered by grade plus schedule, never by size alone.
| Item | Range / Options |
|---|---|
| Standard scope | Factory-made wrought butt-welding fittings, NPS 1/2 - 48 (standard's scope) |
| Butt weld pages on this site | Elbows, tees, reducers, caps, stub ends and pipe bends — each type has its own page in the range below, and each page states the executions recorded for that type |
| Companion standards (general knowledge) | ASME B16.28 covered short-radius elbows and returns in earlier editions of the series (current B16.9 editions include them); ASME B16.25 covers weld bevel ends. These are the companion standards buyers reference alongside B16.9 — they are not executions recorded on this site |
| Wall series | The standard does not fix a schedule series: it covers fittings in any wall thickness that can be produced. That is the standard's basis, not a stock range on this site; order by the schedule of your connecting pipe |
| Materials | A234 WPB and A403 WP304L in the catalogue executions referenced on this site; further grades are confirmed per product at enquiry |
What to State When Ordering to B16.9
- Type and angle — elbow 90° LR, reducing tee, eccentric reducer, cap, stub end.
- Nominal size — and for reducers and reducing tees, both end sizes.
- Schedule or wall — per end where they differ.
- Material grade — for example A234 WPB, A403 WP304L.
- Construction — seamless or welded, where the size allows a choice.
The Range on This Site
Each butt weld family has its own page: butt weld elbows, tees, reducers, caps, stub ends and pipe bends. The B16.9 catalogue records on this site are the ones named on the elbow, tee and reducer pages; the cap, stub end and pipe bend pages state the patterns recorded for their own types, which are not B16.9 records. Forged socket weld and threaded fittings are standardised separately under ASME B16.11 — see the forged fittings range; flanges are covered by ASME B16.5 in the flange range.
Marking and Traceability
B16.9 fittings carry the marking the standard requires — maker, material grade, size and schedule — so a fitting can be identified at goods-in against the order and the mill documentation. Keep the schedule marking visible until installation: it is the fastest check a welding inspector has.
Frequently Asked Questions
Does ASME B16.9 give pressure ratings directly?
Not as a table of numbers. B16.9 ties the fitting's design to straight pipe of the same material and schedule under the applicable piping code — so a Schedule 80 WPB fitting is used with Schedule 80 pipe at that pipe's rated conditions.
What is the difference between B16.9 and B16.28?
Historically the two split the family: B16.9 covered the main butt weld fitting types including long radius elbows, while B16.28 covered wrought steel short radius elbows and 180 degree returns. Current editions of B16.9 have absorbed the short-radius elbows and returns that B16.28 used to cover, so drawings written against older editions may still cite B16.28 for those pieces. Both are dimensional standards from the same ASME series.
Can fittings be supplied to DIN or JIS dimensions instead?
One catalogue bend listing follows the DIN 2605 pattern; beyond that example, name the standard on the enquiry — dimensions differ between systems and are not interchangeable — and whether it can be met is assessed for the specific product before order.
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Send Your Specification
Tell us the size, schedule or pressure class, material grade and quantity for the ASME B16.9 fittings you need. MOQ and lead time are confirmed in the quotation for your exact specification.