Butterfly Valves · Triple Offset Butterfly Valves
VF-8 Series Triple Offset Butterfly Valves
The VF-8 series triple offset butterfly valve: wafer, lug or double-flange body in ANSI Class 150/300/600/900, standard dimensions 4″48″ (100mm1200mm) with lengths to 136″ (3400mm). The three-offset geometry keeps the metal sealing components friction-free through the stroke, contacting only at the final degree of closure; seats are graphite-laminated (bubble-tight, fireproof) or solid metal, with a cobalt-chromium hardfacing alloy 21 hardened disc edge overlay, a one-piece removable shaft-and-disc with internal spline drive, 50,000 cycles without adjustment and a SIL-3 capable rating. Materials span A216 Gr. WCB, A351 Gr. CF8 and A351 Gr. CF8M bodies and discs; fireproofing is certified to ISO 10497 / API 607.
Part of the Triple Offset Butterfly Valves family
Last updated: 2026-11
Specifications
| size range | 4″48″ (100mm1200mm) |
|---|---|
| pressure class | ANSI Class 150/300/600/900 lb |
| temperature range | Laminated Seat: -103 °F to 1022 °F (-75 °C to 550 °C), Solid Metal Seat: -321 °F to 1400 °F (-196 °C to 760 °C) |
| series designation | VF-8 |
| body style | Wafer, Lug, Double Flange |
| maximum length | 136″ (3400mm) |
| body disc materials | A216 Gr. WCB, A351 Gr. CF8, A351 Gr. CF8M |
| seat options | graphite laminated seat, solid metal seat |
| seat overlay | cobalt-chromium hardfacing alloy 21, hardened disc edge overlay |
| cycle life | 50,000 cycles without any adjustments |
| safety integrity level | SIL-3 |
| fire safe | ISO10497, API 607 |
| shaft disc design | one piece removable/repairable shaft and disc with internal spline drive |
| seat fire performance | bubble-tight and fireproof |
| sealing performance | bubble-tight shut-off and zero-leakage performance |
| hostile media design | no elastomers or materials that are prone to corrosion |
Application & selection guidance
Specify the VF-8 series where tight shut-off must survive temperature extremes on metal seats: laminated graphite seats cover -75 to 550 degree C and solid metal seats reach -196 to 760 degree C, so cryogenic through furnace-adjacent duty is one series. Choose wafer or lug for space-critical isolation, double flange where full line-rated end load exists; pick Class 150 for standard process duty and step up through Class 900 as the design margin demands. Where the valve must pass a safety-instrumented-function assessment, the SIL-3 rating with a matched actuator keeps the loop achievable without exotic cost.
Frequently asked questions
What does the third offset actually buy?
The third offset angles the seat cone so the disc touches the seat only at the final degree of closure: the metal sealing components never rub during travel, which removes seat wear from stroking, lets the valve seal bubble-tight metal-to-metal, and allows a lower-torque actuator.
Graphite-laminated seat or solid metal seat?
The graphite-laminated seat is bubble-tight and fireproof and covers -75 to 550 degree C; the solid metal seat extends to -196 to 760 degree C for cryogenic and extreme-temperature duty but is specified where the medium or temperature rules out the laminate. Both carry the cobalt-chromium hardfacing alloy 21 hardened disc edge overlay on the benchmark series.
How maintainable is the series?
The one-piece shaft and disc with internal spline drive is removable and repairable, so seat, disc and stem can be withdrawn for examination without cutting the valve out; the series is rated 50,000 cycles without adjustment.
Ordering & documentation
Documents
Ask for the documentation set you need with the inquiry — typical items for this execution (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
A quotation-ready inquiry states: nominal size and pressure rating, body and seat material preference, end connection, operation, and the service medium with temperature. Typical values on this page are benchmark reference ranges; the binding values are confirmed at quotation.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, keep end-face protectors on until installation, and for elastomer- or PTFE-seated executions avoid prolonged outdoor storage — seat compounds age fastest in direct sunlight and freezing conditions.
Knowledge: selection guides
Request a quote for VF-8 Series Triple Offset Butterfly Valves
Submit the requirement for this execution here — a quotation-ready inquiry states the parameters listed under the message field; the binding values are confirmed at quotation.
What happens to your details is described in our privacy notice.
Get a quotation for VF-8 Series Triple Offset Butterfly Valves
Send size, pressure class and materials for a quotation-ready inquiry — answered with documents and terms.
Request a Quote