球閥 · 固定球閥（Trunnion Mounted）
鑄造固定球閥
鑄造固定球閥將浮動原理再推進一步：球體由上下固定軸固定，管線壓力無法將球體推入下游閥座，操作扭矩在大口徑與高等級下保持可預測。基準頁上的鑄造 A216 WCB 與 A351 CF8/CF8M 結構涵蓋 DN100 至 DN700，Class 150 至 2500 並附公制管線的 PN 標識，-30 至 +220 C，端接 RF、RTJ 與對焊，PTFE 閥座。
屬於 固定球閥（Trunnion Mounted） 系列
最後更新： 2026-11
規格
| Valve body material | ASTM A216 WCB, ASTM A351 CF8, ASTM A351 CF8M |
|---|---|
| Stem material | ASTM A182 F304, ASTM A182 F316 |
| Ball material | ASTM A182 F304, ASTM A182 F316 |
| Seat material | PTFE |
| End connection types | RF, RTJ, BW |
| Operation / closure mode | Manual, Gear Operated, Electric Actuated |
| Nominal valve connection size | DN100 to DN700 |
| Pressure class / nominal rating designation | Class 150 to Class 2500, PN1.6 to PN10.0 |
| Service temperature range | -30 to 220 C |
| Design standards | API 6D, API 608 |
| Face-to-face dimensional standard | API 6D |
| Flange standards | ANSI B16.5 |
| Inspection and pressure-test standards | API 6D, API 598 |
應用與選型指引
Trunnion mounting is the answer where a floating ball would need an impractical actuator: from roughly DN100 upward and at the higher classes, prefer this execution. Choose the seat for the medium (PTFE on the benchmark page; confirm metal-seated options for hot or abrasive duty at quotation), the end connection for the piping class, and the operation for torque and fail-safe needs. The declared size range starts at DN100 - smaller bores belong to the floating executions.
常見問題
Trunnion-mounted vs floating ball valve - when does the trunnion matter?
A floating ball seals by line pressure pressing it against the downstream seat, so seat load and actuator torque grow with bore and pressure. A trunnion-mounted ball is fixed at both ends: the seats carry the load and torque stays moderate. As a rule of thumb, large bores (from about DN100 on the benchmark page) and high classes move to trunnion; small-bore low-class lines stay floating.
Why does the benchmark page list both Class and PN ratings?
Class ratings (ASME B16.34) and PN ratings belong to different flange-standard systems, and this execution is offered into both worlds: ANSI Class 150 to 2500 for ASME piping and a PN marking for DIN-style lines. They are not interchangeable labels - pick the rating that matches the mating flanges and confirm the material group rating at the working temperature.
What information is needed to quote a casting trunnion ball valve?
Nominal size (DN100 to DN700 on the benchmark page), pressure class, body material (WCB or stainless CF8/CF8M executions), seat material, end connection (RF, RTJ or butt weld), operation (manual, gear or electric actuated), and the service medium with temperature. Add any fire-safe or anti-static requirement so the execution and documentation are confirmed at quotation.
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。