規格
| Design standards | MSS SP-117 |
|---|---|
| Nominal valve connection size | Sizes through 4" |
| Pressure Rating | Through ASME Class through 2500 # |
| Valve body material | SA 105, SA 182-F22, SA 182-F91, SA 182-F92, SA 182-F316 |
| actuator options | Actuators - Electric, Pneumatic or Hydraulic |
| body styles | Y-pattern, Angle-pattern, T-pattern |
| bellows design | 6-ply nickel-chromium alloy welded bellows stem seal |
| leakage test | Every bellows assembly is tested for zero leakage using a helium gas mass spectrometer |
| seat disc materials | Solid cobalt-chrome seats and discs, cobalt-free option for nuclear and chemical applications |
| stem design | Rising, non-rotating stem system |
| bonnet design | Pressure seal bonnet |
| material guidance | Stainless steel and nickel-based super alloys |
| pressure rating class range | ASME 150 to 2500 class |
| design qualifications | EPRI, MSS, API, or ISO |
應用與選型指引
Select this execution where fugitive emissions or toxic media rule out packed stems: the 6-ply nickel-chromium alloy welded bellows plus a pressure-actuated backseat give a double barrier, and solid cobalt-chrome seats and discs hold shut-off through high cycle and high-velocity duty (a cobalt-free option exists for nuclear and chemical service). Forged SA 182 F91/F92 bodies carry the high-temperature steam end of the envelope; the in-line renewable Clampseal gland keeps lifecycle cost down where access is frequent.
常見問題
Why a bellows seal instead of a packed stem?
Packed valves need two sliding seal boundaries on the stem; the bellows execution removes both leak paths with a welded 6-ply nickel-chromium alloy bellows, verified by helium mass spectrometer to zero detectable leakage beyond Method 21 protocol - the benchmark choice for light gases and hazardous fluids where fugitive emissions are unacceptable.
What sizes, classes and materials does the execution cover?
The benchmark page lists sizes through 4 inch NPS (from 1/4 inch) with ASME Class ratings through 2500, in standard forgings SA 105, SA 182-F22, SA 182-F91, SA 182-F92 and SA 182-F316 - other materials on request. Bodies come in Y-pattern, Angle-pattern and T-pattern executions with pressure seal bonnets.
How is bellows integrity verified?
Every bellows assembly is tested for zero leakage with a helium gas mass spectrometer before shell and seat leakage testing, and the bellows set meets MSS SP-117 longevity requirements - beyond Method 21 fugitive emissions protocol. The stem is rising and non-rotating so stroke motion never twists the bellows.
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。