Triple Offset Butterfly Valve – Wafer Type
Description
Triple Offset Butterfly Valve – Wafer Type
High Temperature Service, with Cooling Fins
Product Technical Data Sheet
1. General Description
This product is a triple offset butterfly valve of wafer type design, specifically engineered for high temperature service. The valve body is equipped with integral cooling fins to dissipate heat and protect the stem packing and actuator mounting area. It is supplied ready for actuator (pneumatic, electric, or hydraulic) with an ISO 5211 top mounting pad.
The triple offset geometry ensures metal‑to‑metal zero leakage, bi‑directional sealing, and virtually frictionless operation. Hardfaced seat and disc sealing surfaces provide excellent resistance to high temperature erosion, corrosion, and wear.
2. Triple Offset Principle (Quick Reference)
| Offset | Description |
|---|---|
| 1st | Stem axis offset from seat centreline |
| 2nd | Stem axis offset from body centreline |
| 3rd | Seat cone axis offset from body axis |
Result: Cam‑controlled conical sealing, no rubbing during opening/closing, low torque, long service life.
3. Main Technical Parameters
| Parameter | Specification |
|---|---|
| Product Type | Triple offset butterfly valve, wafer type |
| Design Standard | API 609 Category B, ASME B16.34, ISO 10631 |
| Nominal Diameter (DN) | DN50 ~ DN1200 (2″ ~ 48″); larger on request |
| Pressure Rating | ASME Class 150 / 300 / 600 (PN10 ~ PN64 / PN100) |
| Temperature Range | Up to +650°C (depending on material selection) |
| Suitable Media | High‑temperature steam, hot gases, thermal oil, superheated water, refinery process fluids, flue gas |
| Leakage Rate | API 598 Rate A / ISO 5208 Rate A – zero leakage |
| Sealing | Metal‑to‑metal (Stellite hardfacing on seat; laminated metal + graphite on disc) |
| Fire Safe | API 607 / API 6FA |
| Body Type | Wafer (lugged optional) |
4. High Temperature Design Features
| Feature | Description |
|---|---|
| Cooling Fins | Cast or welded fins on upper body / neck area; reduce heat transfer to packing and actuator mounting flange |
| Extended Bonnet / Neck | Provides thermal barrier; protects stem packing from extreme heat |
| Stem Packing | High‑temperature flexible graphite (low emission grade) |
| Bearing Material | High‑temperature self‑lubricating alloy (e.g., Inconel 718 + graphite composite) |
| Disc / Seat Hardfacing | Cobalt‑based Stellite alloy (≥ 0.5 mm thickness) for erosion and wear resistance at high temperature |
| Body Material | High‑temperature capable: WCB (≤425°C), WC6 (≤540°C), WC9 (≤570°C), C12A (≤650°C), or stainless steel 310H / Inconel |
5. Actuator Interface (Ready for Actuator)
| Parameter | Specification |
|---|---|
| Mounting Pad | ISO 5211 top flange (F05 / F07 / F10 / F12 / F14 / F16 / F25 as per valve size) |
| Drive Connection | Square / keyed drive bushing per ISO 5211 |
| Bracket | No gearbox – direct actuator mounting bracket available as optional accessory |
| Actuator Types | Pneumatic (double acting / spring return), electric, hydraulic – customer supplied |
| Stem Extension | Provided if required for thermal isolation |
| Handwheel Override | Optional (side‑mounted or declutchable) |
| Valve Position | Indicated via ISO 5211 top flange (limit switches / positioner to be mounted by customer) |
Note: The valve is supplied without actuator but fully prepared for quick actuator attachment. Top flange dimensions, drive details, and stem height conform to ISO 5211.
6. Connection Type – Wafer
| Parameter | Specification |
|---|---|
| Connection | Wafer type (fits between ASME B16.5 / EN 1092 flanges) |
| Centering | Self‑centering via line flange bolts |
| Gasket Surface | Smooth finish; accepts standard spiral wound or graphite gaskets |
| Face‑to‑Face Length | Per API 609 Category B (short pattern) |
| Installation | No nuts on body – only bolts through line flanges |
Optional: Lugged ends with cooling fins also available upon request.
7. Materials of Construction (High Temperature Service)
| Part | Standard Material (≤540°C) | High‑Grade Material (≤650°C) |
|---|---|---|
| Body | Cast steel WCB | WC6 (1¼Cr‑½Mo), WC9 (2¼Cr‑1Mo), C12A (9Cr‑1Mo‑V), SS310H, Inconel |
| Disc | F22 alloy steel + Stellite hardfacing | Inconel 625 / 718 + Stellite |
| Seat Ring | Integral with body, Stellite hardfaced | Same, or replaceable seat in high‑temp alloy |
| Stem | 17‑4PH (H1150) | Inconel 718, Nimonic 90 |
| Packing | Flexible graphite rings (high density) | Flexible graphite with anti‑extrusion rings |
| Bearings | High‑temp bronze (Al‑bronze) | Graphite‑impregnated nickel alloy |
| Cooling Fins | Cast integral with body / bonnet (same material as body) | Same |
| Fasteners | ASTM A193 B7 / B16 | ASTM A193 B8T Class 2 / B8M |
8. Applicable Standards
| Category | Standard |
|---|---|
| Design | API 609 Cat. B, ASME B16.34, ISO 10631, EN 593 |
| Face‑to‑Face | API 609, ASME B16.10, ISO 5752 |
| Flange connection (wafer) | ASME B16.5, ASME B16.47, EN 1092 |
| Testing | API 598, ISO 5208, EN 12266 |
| Fire safety | API 607, API 6FA |
| High temperature materials | ASME Section II, ASTM specifications |
| Actuator mounting | ISO 5211 |
9. Dimensions & Weights (Wafer Type – Indicative)
Class 150, standard pattern, without actuator. Contact factory for exact dimensional drawings.
| DN | NPS | Face‑to‑Face L (mm) | Height (top of ISO flange) (mm) | Weight (kg) |
|---|---|---|---|---|
| 50 | 2″ | 108 | 120 | 8 |
| 80 | 3″ | 114 | 135 | 12 |
| 100 | 4″ | 127 | 155 | 18 |
| 150 | 6″ | 140 | 190 | 30 |
| 200 | 8″ | 152 | 235 | 48 |
| 250 | 10″ | 165 | 280 | 75 |
| 300 | 12″ | 178 | 325 | 110 |
| 350 | 14″ | 190 | 370 | 150 |
| 400 | 16″ | 216 | 420 | 210 |
| 500 | 20″ | 229 | 510 | 320 |
| 600 | 24″ | 267 | 600 | 480 |
Heights are approximate for Class 150; higher classes increase dimensions and weight. Cooling fins add 50–150 mm to overall height depending on size.
10. Cooling Fins Detail
| Parameter | Description |
|---|---|
| Material | Same as body (carbon steel, alloy steel, stainless steel) |
| Configuration | Longitudinal radial fins cast or welded around the neck |
| Surface area | Optimised for natural air convection |
| Effect | Reduces stem packing temperature by 50–100°C vs. non‑finned design |
| Standard | Fins provided for all sizes when operating temperature exceeds 350°C (662°F) |
11. Testing & Inspection (High Temperature Service)
| Test | Condition | Requirement |
|---|---|---|
| Shell (hydrostatic) | 1.5× pressure rating at ambient | No leakage, no deformation |
| High‑pressure seat (hydrostatic) | 1.1× pressure rating at ambient | Zero leakage (Rate A) |
| Low‑pressure seat (air) | 0.6 MPa | Zero visible bubbles |
| High temperature functional test | Optional (at customer request) | Verify torque and sealing at operating temperature |
| Material verification | Positive material identification (PMI) | As required |
| NDE | Liquid penetrant (PT) or radiography (RT) | Per ASME B16.34 |
12. Applications
-
Refineries – hot oil, FCCU flue gas, regenerator lines
-
Power plants – superheated steam, boiler circulation, turbine bypass
-
Heat recovery steam generators (HRSG)
-
Chemical plants – high temperature thermal fluids, process heaters
-
Incinerators / waste heat recovery
-
Steam distribution networks (high temperature & high pressure)
13. Ordering Information
To ensure correct valve selection, please provide:
-
Valve size (DN / NPS) and pressure class
-
Operating temperature (max / min) and medium
-
Body / disc / seat material required
-
Required connection type: wafer (or lugged if preferred)
-
Cooling fins – required if temperature > 350°C (standard for high temp service)
-
Actuator ready – ISO 5211 top flange size and drive details (or specify actuator to be supplied by customer)
-
Any additional tests (high temperature functional test, NDE, PMI, etc.)
-
Special coatings for high temperature (e.g., high‑temp paint up to 650°C)
Note: This valve is designed for high temperature service and is supplied without actuator. The ISO 5211 mounting pad and drive are machined precisely for direct actuator mounting. Cooling fins are mandatory for applications above 400°C (752°F) to protect stem packing and actuator components.
