ASME B16.11 forged steel fittings are the small-bore high-pressure workhorses of any process plant — the elbows, tees, couplings, plugs and unions that knit instrument loops, sample lines, chemical-injection branches, and high-pressure utility lines together. RP Sales coordinates B16.11 supply from BIS-licensed Indian forging shops in the full 1/8" to 4" NPS range, across 2000#, 3000#, 6000# and 9000# pressure classes, in A105 carbon steel, F304 / F316 stainless, and F11 / F22 / F91 Cr-Mo alloy. This page is the buyer reference: what each pressure class matches, when to choose socket-weld vs threaded, and what documentation we ship with the order.
What ASME B16.11 covers
ASME B16.11 is the standard for forged steel fittings with socket-welding and threaded end connections in nominal sizes from 1/8" through 4" NPS. The fittings are forged from solid stock (A105, F-grade) and then machined to bore, socket depth, and end profile per the standard's dimensional tables. Pressure classes are 2000, 3000, 6000 (socket-weld and threaded) and 9000 (socket-weld only) — each class corresponds to a maximum working pressure at 38 °C and a matching schedule of pipe the fitting can be welded to.
B16.11 is the dominant spec for small-bore secondary piping in Indian refineries, fertiliser plants, ammonia / urea trains, IOCL / HPCL / BPCL plants, and the small-bore instrument-loop scope on every petrochemical revamp. For larger sizes (above 4" NPS) and the main process lines, the buyer typically moves to ASME B16.9 buttweld fittings instead — see our separate seamless pipe catalogue for the matching pipe stock.
Pressure classes & matching pipe schedule
| Class | End connection | Matching pipe schedule | Typical use |
|---|---|---|---|
| 2000 | Threaded | Sch 80 | Utility air, low-pressure water small-bore |
| 3000 | Socket-Weld / Threaded | Sch 80 | Refinery secondary lines, instrument loops |
| 6000 | Socket-Weld | Sch 160 | High-pressure utility, chemical injection |
| 6000 | Threaded | XXS | Where socket-weld access is impractical |
| 9000 | Socket-Weld | XXS | Ultra-high-pressure small-bore |
Fitting types we supply
- Elbows — 90° and 45°, equal-size both ends.
- Tees — equal and reducing (size run × run × branch).
- Crosses — rare in new design; usually replaced by two tees.
- Couplings — full, half, reducing — pipe-to-pipe joining and reducing the bore for instrument tie-ins.
- Caps, plugs, bushings — end closures, threaded blanks, size adapters.
- Unions — threaded three-piece joints for periodic disassembly on instrument lines.
Material grades
Carbon & alloy steel forged fittings: A105, A350 LF2 (low-temperature carbon), F11, F22, F91. Stainless steel grades: F304, F304L, F316, F316L, F321. Duplex and super-duplex (F51, F53, F55) are available on indent for marine, offshore and aggressive chemical service. Low-temperature service (below −29 °C) shifts to A350 LF2 or F304L with Charpy impact testing per ASME B31.3.
Typical applications
High-pressure instrument piping in refinery distillation units, sample loops in petrochemical plants, chemical-injection lines in oil & gas, hydrogen-service small-bore branches, ammonia-plant manifolds, fertiliser-plant urea lines, power-plant chemical-feed loops. The combination of forged construction, machined sockets, and high pressure class makes B16.11 the default for any small-bore application where the alternative (slip-on or threaded brass / GI parts) would not meet the pressure-temperature envelope.
Related catalogue and reference pages: weld neck flange 150#, seamless pipes, ASTM A106, ASTM A335 alloy pipe, ASTM A312 stainless, MTC & TPI documentation, request a quote.
FAQ — B16.11 fitting selection & procurement
What is the difference between ASME B16.11 forged fittings and B16.9 buttweld fittings?
Which pressure class should I order — 2000#, 3000#, 6000# or 9000#?
Are socket-weld or threaded ends preferred?
What fitting types are covered under ASME B16.11?
Do you supply F11 / F22 / F91 high-temperature alloy forged fittings?
Can you supply NACE MR0175 / ISO 15156 sour-service forged fittings?
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