蝶閥 · 三偏心蝶閥
VF-8 系列三偏心蝶閥
VF-8 系列三偏心蝶閥：對夾、凸耳或雙法蘭閥體，ANSI Class 150/300/600/900，標準尺寸 4″-48″（100mm-1200mm），長度可至 136″（3400mm）。三偏心幾何使金屬密封部件在全行程中無摩擦，僅在關閉最後一度接觸；閥座為石墨疊層（氣泡級密封、防火）或實心金屬，蝶盤邊緣堆焊鈷鉻合金 21 硬化層、一體式可拆軸盤配內花鍵傳動、免調整 50,000 次循環，並具 SIL-3 能力額定。材料涵蓋 A216 Gr. WCB、A351 Gr. CF8 與 A351 Gr. CF8M 閥體與蝶盤；防火經 ISO 10497 / API 607 認證。
屬於 三偏心蝶閥 系列
最後更新： 2026-11
規格
| series designation | VF-8 |
|---|---|
| body style | Wafer, Lug, Double Flange |
| Pressure Rating | ANSI Class 150/300/600/900 lb |
| Nominal valve connection size | 4″48″ (100mm1200mm) |
| maximum length | 136″ (3400mm) |
| Service 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) |
| 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 |
應用與選型指引
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.
常見問題
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.
訂購與文件
文件
請在詢問時一併說明您需要的文件組合——此結構的常見項目（材質證明、按所列檢驗標準的測試報告、尺寸圖）將於報價時確認並隨附供應。
報價
可直接報價的詢問應說明：公稱口徑與壓力額定、閥體與閥座材質偏好、端部連接、操作方式，以及含溫度的使用介質。本頁的典型值為基準參考範圍；具有約束力的數值於報價時確認。
樣品與供應
供應條件、訂購數量與交期按訂單議定——請在詢問時說明目的地國家與所需時程。
儲存與運輸
閥門儲存時應保護閥座與密封件免受紫外線、臭氧與變形影響，安裝前保留端面保護蓋；彈性體或 PTFE 閥座結構應避免長期戶外存放——閥座材料在陽光直射與冰凍條件下老化最快。