Butt-Weld Caps
Wrought butt-weld caps to ASME B16.9 that close the end of a pipe run with a domed, butt-welded closure, in carbon, alloy, stainless, duplex and nickel grades.
Technical specification
| Parameter | Specification |
|---|---|
| Product | Wrought butt-weld fittings (elbows, tees, reducers, caps, stub ends, bends) |
| Dimensional standard | ASME B16.9 (long radius) · B16.28 (short radius) |
| End preparation | Bevel to ASME B16.25 |
| Size range | 1/2" – 48" NPS (larger bends made to order) |
| Wall / schedule | Sch 5S – XXS and custom, per ASME B36.10M / B36.19M |
| Material specifications | ASTM A234, A403, A420, A815, B366 |
| Sour service | NACE MR0175 / ISO 15156 where specified |
| Documentation | EN 10204 3.1 / 3.2, PMI, TPI |
How it is made
Wrought butt-weld fittings are hot- or cold-formed from pipe, plate or forging — hot forming, bulge forming, deep drawing or forging — then heat treated and machined to ASME B16.9/B16.28. Carbon and low-alloy fittings are supplied in the specified heat-treatment condition (as-formed, normalised, normalised & tempered, or quenched & tempered for the higher grades); austenitic stainless is solution annealed and quenched; duplex is solution annealed and rapidly cooled to maintain phase balance. Weld ends are bevelled to ASME B16.25 to match the mating pipe wall, and the wall tolerance is that of the fitting standard, not the pipe −12.5% allowance.
Grades & materials
All grades supplied for this product family, with representative chemistry. Exact grade, class and condition are confirmed per order.
| Material family | Grades | UNS | Standard | Service |
|---|---|---|---|---|
| Carbon steel | A234 WPB, WPC | — | ASME B16.9 / ASTM A234 | General service |
| C-Mo & Cr-Mo alloy | A234 WP1, WP12, WP11, WP22, WP5, WP9, WP91, WP911 | — | ASME B16.9 / ASTM A234 | High-temperature & creep |
| Low-temp carbon | A420 WPL6, WPL9, WPL3 | — | ASME B16.9 / ASTM A420 | Low temperature |
| Austenitic stainless | A403 WP304/304L/304H, 309, 310, 316/316L/316H, 317/317L, 321/321H, 347/347H, 348 | — | ASME B16.9 / ASTM A403 | Corrosion / high temp |
| Duplex / super duplex | A815 S31803/S32205 (2205), S32750 (2507), S32760, S31500, S32550 | — | ASME B16.9 / ASTM A815 | Chloride / sour |
| Nickel alloys | B366 WPNCI (600), WPNCMC (625), WPNIC (800), WPHC276 (C-276), WPHB2 (B-2), WPHC22 (C-22), WPN (Ni 200), WPNC (Monel 400) | — | ASME B16.9 / ASTM B366 | Severe corrosion |
Chemical composition (representative)
| Grade | C | Mn | Si | Cr | Ni | Mo | Other |
|---|---|---|---|---|---|---|---|
| A234 WPB | 0.30 max | 0.29–1.06 | 0.10 min | — | — | — | — |
| A234 WP11 | 0.05–0.15 | 0.30–0.60 | 0.50–1.00 | 1.00–1.50 | — | 0.44–0.65 | — |
| A234 WP22 | 0.05–0.15 | 0.30–0.60 | 0.50 max | 1.90–2.60 | — | 0.87–1.13 | — |
| A234 WP91 | 0.08–0.12 | 0.30–0.60 | 0.20–0.50 | 8.0–9.5 | 0.40 max | 0.85–1.05 | V 0.18–0.25, Nb 0.06–0.10, N 0.03–0.07 |
| A420 WPL6 | 0.30 max | 0.60–1.35 | 0.15–0.30 | — | — | — | — |
| A403 304L | 0.030 max | 2.00 max | 0.75 max | 18.0–20.0 | 8.0–12.0 | — | — |
| A403 316L | 0.030 max | 2.00 max | 0.75 max | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
| A403 321 | 0.08 max | 2.00 max | 0.75 max | 17.0–19.0 | 9.0–12.0 | — | Ti 5×C–0.70 |
| A815 S32205 | 0.030 max | 2.00 max | 1.00 max | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | N 0.14–0.20 |
| A815 S32750 | 0.030 max | 1.20 max | 0.80 max | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | N 0.24–0.32 |
| B366 625 | 0.10 max | 0.50 max | 0.50 max | 20.0–23.0 | 58.0 min | 8.0–10.0 | Nb 3.15–4.15, Fe 5.0 max |
| B366 C-276 | 0.01 max | 1.00 max | 0.08 max | 14.5–16.5 | bal | 15.0–17.0 | W 3.0–4.5, Fe 4.0–7.0 |
Standards & specifications
Dimensional
- ASME B16.9 factory-made wrought butt-weld fittings
- ASME B16.28 short-radius elbows & returns
- ASME B16.25 welding-end preparation
- MSS SP-75 high-yield (WPHY) pipeline fittings
Material & service
- ASTM A234 carbon & alloy; A420 low-temp
- ASTM A403 austenitic; A815 duplex
- ASTM B366 nickel-alloy fittings
- NACE MR0175 / ISO 15156 sour service
Mechanical properties (representative grades)
Representative grades — full MTC values on request. Values are ASTM/ASME specification minima or ranges at room temperature.
| Grade | Type | Tensile (MPa) | Yield min (MPa) | Elong min (%) |
|---|---|---|---|---|
| A234 WPB | Carbon | 415–585 | 240 | 22 |
| A234 WPC | Carbon | 485–655 | 275 | 20 |
| A234 WP1 | C-½Mo | 380– | 205 | 22 |
| A234 WP12 Cl.1 | 1Cr-½Mo | 415–585 | 220 | 22 |
| A234 WP11 Cl.1 | 1¼Cr-½Mo | 415–585 | 205 | 20 |
| A234 WP22 Cl.1 | 2¼Cr-1Mo | 415–585 | 205 | 20 |
| A234 WP22 Cl.3 | 2¼Cr-1Mo | 515–690 | 310 | 20 |
| A234 WP5 | 5Cr-½Mo | 415–590 | 205 | 20 |
| A234 WP9 | 9Cr-1Mo | 415–590 | 205 | 20 |
| A234 WP91 | 9Cr-1Mo-V | 585– | 415 | 20 |
| A234 WP911 | 9Cr-1Mo-V-W | 620– | 440 | 20 |
| A420 WPL6 | Low-temp C (−46 °C) | 415–585 | 240 | 22 |
| A420 WPL9 | Ni (−73 °C) | 435– | 315 | 22 |
| A420 WPL3 | 3½Ni (−101 °C) | 450– | 240 | 22 |
| A403 WP304 / 304H | Austenitic SS | 515 | 205 | 35 |
| A403 WP304L | Austenitic SS | 485 | 170 | 35 |
| A403 WP309 / 310 | Austenitic SS | 515 | 205 | 35 |
| A403 WP316 / 316H | Austenitic SS | 515 | 205 | 35 |
| A403 WP316L | Austenitic SS | 485 | 170 | 35 |
| A403 WP317 | Austenitic SS | 515 | 205 | 35 |
| A403 WP317L | Austenitic SS | 515 | 205 | 35 |
| A403 WP321 / 321H | Austenitic SS | 515 | 205 | 35 |
| A403 WP347 / 347H | Austenitic SS | 515 | 205 | 35 |
| A403 WP348 | Austenitic SS | 515 | 205 | 35 |
| A815 WPS31803 (2205) | Duplex | 620 | 450 | 25 |
| A815 WPS32205 (2205) | Duplex | 655 | 485 | 25 |
| A815 WPS32750 (2507) | Super duplex | 795 | 550 | 15 |
| A815 WPS32760 | Super duplex | 750 | 550 | 25 |
| A815 WPS32550 | Super duplex | 760 | 550 | 15 |
| B366 WPN (Ni 200) | Nickel | 380 | 105 | 40 |
| B366 WPNC (Monel 400) | Ni-Cu | 480 | 195 | 35 |
| B366 WPNCI (Inconel 600) | Ni-Cr | 550 | 240 | 30 |
| B366 WPNIC (Incoloy 800) | Ni-Fe-Cr | 450 | 170 | 30 |
| B366 WPNCMC (Alloy 625) | Ni-Cr-Mo | 760 | 345 | 30 |
| B366 WPHC276 (C-276) | Ni-Mo-Cr | 690 | 283 | 40 |
| B366 WPHB2 (B-2) | Ni-Mo | 760 | 350 | 40 |
| B366 WPHC22 (C-22) | Ni-Cr-Mo | 690 | 310 | 45 |
Testing, inspection & documentation
| Test / document | Detail |
|---|---|
| Chemical / PMI | Product-analysis chemistry to the ASTM spec; PMI (XRF/OES) on alloy, stainless & nickel grades |
| Tensile | Tensile strength, yield and elongation per grade; specimens per ASTM A370 |
| Impact (Charpy) | For low-temp grades (A420 WPL6 −46 °C, WPL9 −73 °C, WPL3 −101 °C) and where specified |
| Hardness | Brinell/Rockwell; NACE MR0175 hardness limits for sour service |
| Corrosion | IGC per ASTM A262 (austenitic); ferrite & phase check for duplex |
| NDE | UT / RT / MPI (ferromagnetic) / DPT as specified; 100 % visual |
| Certification | EN 10204 3.1 mill certificate as standard; 3.2 with third-party endorsement |
Applications & industries served
Available forms, sizes & range
Cap length E is controlled standard geometry; wall follows the ordered schedule and weight is quoted per item.
| NPS (DN) | Length E (mm) | E (in) | Availability | Enquiry |
|---|---|---|---|---|
| 1" (DN25) | 38 | 1.5 | Regular stock | |
| 1 1/2" (DN40) | 38 | 1.5 | Regular stock | |
| 2" (DN50) | 38 | 1.5 | Regular stock | |
| 2 1/2" (DN65) | 38 | 1.5 | Regular stock | |
| 3" (DN80) | 51 | 2.01 | Regular stock | |
| 4" (DN100) | 64 | 2.52 | Regular stock | |
| 5" (DN125) | 76 | 2.99 | Regular stock | |
| 6" (DN150) | 89 | 3.5 | Regular stock | |
| 8" (DN200) | 102 | 4.02 | Regular stock | |
| 10" (DN250) | 127 | 5.0 | Regular stock | |
| 12" (DN300) | 152 | 5.98 | Regular stock | |
| 14" (DN350) | 165 | 6.5 | Made to order | |
| 16" (DN400) | 178 | 7.01 | Made to order | |
| 18" (DN450) | 203 | 7.99 | Made to order | |
| 20" (DN500) | 229 | 9.02 | Made to order | |
| 24" (DN600) | 267 | 10.51 | Made to order |
Frequently asked questions
How is a cap fitted?
It is butt-welded to the pipe end with a qualified WPS, matching the bevel and wall to the pipe for a full-penetration weld.
How is the length set?
Cap length E is standard geometry per ASME B16.9, independent of wall; weight is quoted per item by schedule.
Which grades are available?
Carbon (A234), low-temp (A420), Cr-Mo (WP11/22/91), stainless (A403), duplex (A815) and nickel (B366), confirmed per order.
Request a quote
Send your requirement to Sagiant Piping Industries and our team responds with grade, material selection, availability and pricing for butt-weld cap. Attach a BOQ, line list or drawing for a faster, more accurate quotation.
- Fast RFQ response with grade & material-selection support
- EN 10204 3.1 / 3.2 certification, PMI & third-party inspection
- BOQ & line-list project supply — India & export
Mechanical & chemical values shown are ASTM/ASME specification figures; certified heat-specific values appear on the MTC. Availability is confirmed with the quotation.
