Butterfly Valve
Wafer, lug, double-flanged and triple-offset butterfly valves from 2" to 48" in CF8M, CF3M, Duplex and WCB — EPDM, PTFE and metal seats, lever, gear, pneumatic or electric, tested to API 598.
What is Butterfly Valves?
A butterfly valve is a quarter-turn isolation and throttling valve in which a disc rotates within the pipe bore. Steelco supplies wafer, lug, double-flanged and triple-offset butterfly valves from 2" to 48" in CF8, CF8M, CF3M, Duplex CD3MN, Super Duplex CE3MN and WCB cast carbon steel, rated PN 10 to PN 40 and ASME Class 150 to 300, with EPDM, NBR, PTFE and metal seats. Actuation options include lever, gearbox, pneumatic and electric, all tested to API 598 before dispatch.
All grades we stock in butterfly valves.
Click any grade for its full chemical composition, mechanical properties, equivalents and typical applications. Every grade ships with EN 10204 3.1 / 3.2 certification from our Mumbai stockyard.
Why Choose Butterfly Valves
Four body styles
Wafer, lug, double-flanged and triple-offset designs so the valve suits both end-of-line service and full pipeline isolation.
Soft and metal seats
EPDM, NBR, Viton and PTFE liners for bubble-tight shut-off to –20 to 200 °C; laminated metal seats for 425 °C and fire-safe service.
Corrosion-matched trim
Disc and stem in 316, Duplex 2205, Super Duplex or Monel to match the line material — no galvanic mismatch at the seat.
Low operating torque
Offset disc geometry lifts the seat clear on opening, reducing torque, seat wear and actuator size.
Actuation ready
ISO 5211 mounting pads for gearbox, pneumatic and electric actuators, with limit switches and positioners fitted on request.
Tested before dispatch
Shell and seat tests to API 598, with fire-safe qualification to API 607 available on metal-seated valves.
Technical Specifications
| Attribute | Details |
|---|---|
| Valve Types | Wafer · Lug · Double-flanged · Triple-offset (high performance) |
| Size Range | 2" (DN 50) to 48" (DN 1200) |
| Pressure Rating | PN 10 · PN 16 · PN 25 · PN 40 · ASME Class 150 / 300 |
| Body Material | CF8 · CF8M · CF3M · CD3MN Duplex · CE3MN Super Duplex · WCB carbon steel · Ductile iron |
| Disc Material | SS 304 · 316 · 316L · Duplex 2205 · Super Duplex 2507 · Aluminium bronze |
| Seat / Liner | EPDM · NBR · Viton · PTFE · RPTFE · Laminated metal (SS + graphite) |
| Stem Material | SS 410 · 316 · 17-4 PH · Duplex 2205 |
| Temperature Range | –29 °C to 200 °C (soft seat) · up to 425 °C (metal seat) |
| Operation | Lever · Worm gearbox · Pneumatic (double-acting / spring-return) · Electric |
| Standards | API 609 · ASME B16.34 · EN 593 · API 598 (test) · API 607 (fire safe) |
| Face-to-Face | ASME B16.10 · EN 558 Series 20 / 13 |
| Certification | EN 10204 3.1 · 3.2 with witness · NACE MR0175 on request |
Grade availability by size band
| Grade | UNS | 2"–4" | 6"–10" | 12"–20" | 24"–36" | 40"–48" |
|---|---|---|---|---|---|---|
| Wafer, soft seat | PN 16 | — | ||||
| Lug, soft seat | PN 16 / Class 150 | — | ||||
| Double-flanged | PN 10 / PN 16 | — | ||||
| Triple-offset, metal seat | Class 150 / 300 | — | ||||
| Duplex / Super Duplex body | Class 150 / 300 | — | — |
Note: Sizes above 48" and special trims are manufactured to order on a 4–8 week lead time.
Use our free metal weight calculator — bars, sheets, plates, pipes and sections.
Grade chemistry and mechanical properties supplied in butterfly valves.
Chemical composition and mechanical properties are grade properties, not form properties — the same grade keeps the same chemistry whether it is supplied as sheet, plate or coil. The tables below list the specified limits for each grade we stock in butterfly valves. Values are weight percent (maximum unless a range is shown); mechanical values are minima in the annealed condition.
Chemical composition (weight %)
| Grade | C | Mn | Si | P | S | Cr | Ni | Mo | N | Cu |
|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A351 CF8UNS J92600 | 0.08 | 1.50 | 2.00 | 0.040 | 0.040 | 18.0–21.0 | 8.0–11.0 | 0.50 | — | — |
| ASTM A351 CF8MUNS J92900 | 0.08 | 1.50 | 1.50 | 0.040 | 0.040 | 18.0–21.0 | 9.0–12.0 | 2.0–3.0 | — | — |
| ASTM A351 CF3MUNS J92800 | 0.03 | 1.50 | 1.50 | 0.040 | 0.040 | 17.0–21.0 | 9.0–13.0 | 2.0–3.0 | — | — |
| ASTM A890 CD3MN (4A)UNS J92205 | 0.03 | 1.50 | 1.00 | 0.040 | 0.020 | 21.0–23.5 | 4.5–6.5 | 2.5–3.5 | 0.10–0.30 | 1.00 |
| ASTM A890 CE3MN (5A)UNS J93404 | 0.03 | 1.50 | 1.00 | 0.040 | 0.040 | 24.0–26.0 | 6.0–8.0 | 4.0–5.0 | 0.10–0.30 | — |
| ASTM A216 WCBUNS J03002 | 0.30 | 1.00 | 0.60 | 0.035 | 0.035 | 0.50 | 0.50 | 0.20 | — | 0.30 |
Balance iron. Single figures are maximum limits. Mill test certificates to EN 10204 3.1 are issued with every dispatch.
Mechanical properties (annealed, minimum)
| Grade | Tensile Strength (min) | Yield Strength (min) | Elongation (min) | Condition | Tensile Strength | Service Temperature |
|---|---|---|---|---|---|---|
| ASTM A351 CF8 | 485 MPa (70 ksi) | 205 MPa (30 ksi) | 35% | Solution annealed, 1040 °C min, water quenched | — | — |
| ASTM A351 CF8M | 485 MPa (70 ksi) | 205 MPa (30 ksi) | 30% | Solution annealed, 1040 °C min, water quenched | — | — |
| ASTM A351 CF3M | 485 MPa (70 ksi) | 205 MPa (30 ksi) | 30% | Solution annealed, 1040 °C min, water quenched | — | — |
| ASTM A890 CD3MN (4A) | 620 MPa (90 ksi) | 415 MPa (60 ksi) | 25% | Solution annealed, 1120 °C min, water quenched | — | — |
| ASTM A890 CE3MN (5A) | 690 MPa (100 ksi) | 515 MPa (75 ksi) | 18% | Solution annealed, 1120 °C min, water quenched | — | — |
| ASTM A216 WCB | — | 250 MPa (36 ksi) | 22% | — | 485 – 655 MPa (70 – 95 ksi) | −29 °C to 425 °C |
Typical annealed values; actual results are stated on the heat-specific mill test certificate.
Application Sectors
Water & Wastewater
Double-flanged EPDM-seated valves on treatment plant headers and pumping mains.
Chemical Processing
PTFE-lined CF8M valves on acid, solvent and slurry lines.
Oil & Gas
Triple-offset metal-seated valves for fire-safe isolation to API 607.
Power Plants
Cooling-water, condenser and ash-handling isolation up to 48".
Marine & Desalination
Duplex and Super Duplex bodies on seawater intake and brine service.
HVAC
Lug-type valves on chilled and hot-water circuits with gear operators.
Pharmaceutical
Hygienic 316L valves with PTFE seats for CIP and clean utility lines.
Pulp & Paper
Metal-seated valves on stock, bleach and steam service.
Cut, finished and certified to your drawing.
Material leaves our Mumbai facility finished to your specification — not as raw stock.
Why buy from Steelco.
Steelco Metal & Alloys is a Mumbai-based stockist, importer and exporter of stainless steel and nickel alloys, shipping certified material worldwide.
Quality & testing on every dispatch
- EN 10204 3.1 mill test certificate on every dispatch
- 3.2 certification with TÜV / SGS / BV / Lloyd's / IRS / IBR witness on request
- Positive Material Identification (PMI) with portable XRF / OES
- Dye-penetrant (DPT), ultrasonic (UT) and hydro testing on request
- NACE MR0175 / ISO 15156 compliance for sour service
- PED 2014/68/EU compliance for pressure equipment
- Heat-number stencilling and marking for full traceability
Deep ready stock
Butterfly valves stocked from 2" to 24" in CF8M, CF3M and Duplex bodies with EPDM, PTFE and metal seats — most sizes dispatched from Mumbai within 3–7 working days, actuated or manual.
Mill-direct sourcing
Approved supply from Jindal, JSL, Outokumpu, Aperam, Acerinox, Sandvik and leading Japanese and Korean mills — every item traceable to a named producer.
Full certification
EN 10204 3.1 mill test certificate as standard, 3.2 with TÜV, SGS, BV, Lloyd's, IRS or IBR witness, plus PMI, DPT and UT reports on request.
On-time worldwide delivery
Regular export shipments to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA via Nhava Sheva (JNPT), Mundra and Mumbai ports.
How your material is packed and shipped.
Every consignment leaves our Mumbai facility protected for transit and documented for customs, whether it moves by road within India or by sea to an overseas port.
Domestic & export packing
- Valves supplied in closed position with disc protected
- Flange faces covered with plastic protectors
- Individually bubble-wrapped and boxed up to 8"
- Wooden crates with bolting and chocking for larger valves
Global shipments
- HS Code: 8481 80 · 8481 90 (parts)
- FOB / CFR / CIF terms via Nhava Sheva (JNPT), Mundra and Mumbai ports
- Documentation: commercial invoice, packing list, MTC, bill of lading, COO, insurance
- Regular exports to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA
Ready to price your requirement?
Share grade, size and quantity — our Mumbai desk responds with pricing, stock position and lead time, usually the same working day.
Frequently asked questions.
Answers to the questions our Mumbai desk is asked most often.
What is the difference between a wafer and a lug butterfly valve?
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A wafer valve is clamped between two flanges by through bolts and cannot be used at the end of a line. A lug valve has threaded inserts, so each flange bolts to the valve independently and downstream pipework can be removed with the valve holding pressure.
Which seat material should I choose?
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EPDM suits water, steam and mild chemicals to 130 °C; NBR suits oils and hydrocarbons; PTFE and RPTFE handle aggressive chemicals to 200 °C; laminated metal seats are used above 200 °C and where fire-safe performance to API 607 is required.
What is a triple-offset butterfly valve?
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It offsets the stem behind the disc, offsets the stem from the pipe centreline, and inclines the seat cone axis. The result is a frictionless, torque-seated metal seal giving bubble-tight, fire-safe shut-off usable up to 425 °C.
Can butterfly valves be used for throttling?
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Yes, within roughly 20° to 70° of disc opening. Outside that band control authority is poor and disc flutter or seat damage can occur, so a control valve is preferred for tight modulating duty.
Do you supply actuated valves ready to install?
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Yes. We size and mount worm gearboxes, pneumatic and electric actuators on ISO 5211 pads, add limit switches, solenoids and positioners, and function test the assembly before dispatch.