閘閥 · 刀型閘閥（knife gate）
單向刀型閘閥
單向刀型閘閥僅單側密封：薄刀形閘板推入為單一流向定尺寸的彈性密封（基準頁為聚氨酯、EPDM、NBR 或 Viton）。依 MSS SP-81 建造，基準結構涵蓋 DN50 至 DN450，對夾與凸耳端，PN10 / Class 150 任務，閥體碳鋼、球墨鑄鐵或 SS316，刀板 SS304/SS316，PTFE 填料——紙漿、漿料與乾固體管線的標準截斷閥。
屬於 刀型閘閥（knife gate） 系列
最後更新： 2026-11
規格
| Valve body material | Carbon Steel, Ductile Iron, SS316 |
|---|---|
| Disc Materials | SS304 (knife), SS316 (knife) |
| Trim material | SS304 (disc), SS316L (disc) |
| Packing Materials | PTFE |
| Seat material | Polyurethane, EPDM, NBR, VITON |
| Nominal valve connection size | DN50 to DN450 |
| Pressure class / nominal rating designation | Class 150, Class 30, PN10 |
| End connection types | Wafer Type, Lug Type |
| Operation / closure mode | Handwheel, Electric Actuated, Pneumatic Actuated |
| Design standards | MSS SP-81 |
| Face-to-face dimensional standard | MSS SP-81 |
| Flange standards | DIN, JIS |
| Inspection and pressure-test standards | API 598 |
| Service temperature range | -29°C to 538°C |
| media | Pulp, Coal ash, Sewage, Food |
Pressure class is shown as collected: "Class 150, Class 30, PN10". The source text's "Class 30" is retained verbatim as a recorded source difference — it is commonly read as a typographical variant of Class 300, but that reading is not asserted here; the governing class is confirmed at quotation.
應用與選型指引
Use for one-direction isolation of pulps, sludges, dry solids and other media a full-bore wedge would trap: the thin blade cuts through the column and seats into the elastomer seal. Direction matters - install with flow against the sealed side, because the unsealed side does not shut off. Choose the body (carbon steel for general duty, SS316 for corrosive media) and the seal compound against the medium; wafer ends save weight, lug ends allow downstream dismantling. This is an isolation valve, not a throttle valve.
常見問題
Unidirectional vs bidirectional knife gate valve - what changes in practice?
A unidirectional knife gate seals on one face only and must be installed with the flow against the sealing side; a bidirectional execution seals either way and suits lines where flow reverses or the installation orientation could be mistaken. Unidirectional valves are simpler and more economical; the cost is a mandatory correct orientation - verify the flow direction on the piping drawing before ordering.
Why does MSS SP-81 appear on the specification alongside API 598?
MSS SP-81 is the industry standard for bonnetless knife gate valves - it defines the thin wafer and lug body envelope, the face-to-face dimensions and the construction for this valve type. API 598 on the benchmark page is the inspection and test standard applied to it. The two are complementary: one defines the product, the other how it is tested, so both appearing on a knife gate specification is normal.
What information is needed to quote a unidirectional knife gate valve?
Nominal size (DN50 to DN450 on the benchmark page), pressure (PN10 / Class 150 on the benchmark page), end type (wafer or lug), body material (carbon steel, ductile iron or SS316), blade and seal compound against the medium, packing, and the operation (handwheel, electric or pneumatic actuated). Describe the medium precisely - solids content and temperature decide the seal compound.
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。