ASME B16.28 was the standard for wrought steel buttwelding short radius elbows and returns. It has been withdrawn, and short radius (SR) fittings are now covered by ASME B16.9, but many drawings, piping specifications and purchase orders still call for "B16.28 elbows", so buyers continue to search for it by name.
Raaj Fittings manufactures 90° short radius elbows and 180° short radius returns to the current ASME B16.9 requirements, which cover the former B16.28 fittings, at our two plants in India in carbon, low-temperature, alloy and stainless steel, duplex and nickel alloys.
A short radius elbow has a centreline radius of 1.0 times the nominal pipe size (1D), against 1.5D for a long radius elbow. A 4" SR 90° elbow therefore has a centre-to-end of about 102 mm, compared with 152 mm for a long radius elbow. 180° returns are made in the same short radius.
Order short radius fittings to ASME B16.9 and give the material grade, size and schedule as for any buttweld fitting, for example: "Elbow 90° SR, 4" SCH 40, ASTM A234 WPB, ASME B16.9". A purchase order that still names B16.28 is met by B16.9 SR fittings.
Every short radius fitting is made from PMI-verified material, dimensionally inspected against the ordered standard and marked with material, size, rating and heat number. Orders are supplied with EN 10204 3.1 certificates; EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request.
No. ASME B16.28 was withdrawn and its short radius elbows and returns were incorporated into ASME B16.9, which is the standard to order to today.
A short radius elbow has a centreline radius equal to the nominal pipe size (1D), compared with 1.5D for a long radius elbow.
Where pressure drop, erosion or pigging are concerns, and where the piping specification restricts them. Long radius elbows are the default choice.
Yes, 180° short radius returns are made alongside 90° short radius elbows, in the same materials and schedules.