API · ASME · DIN · EN 標準工業閥門

微啟式安全閥

微啟式安全閥僅開啟閥座直徑的一小部分，沿閥座面釋放經計量的少量流體——這種比例式行為適合液體系統以及全開排放會過度擾動的任務。產品範圍涵蓋彈簧加載結構，閥體為鑄鐵、WCB、SS304 或 SS316，噴嘴、調節環、閥盤、導向套與閥桿組為 2Cr13、SS304 或 SS316，碳鋼閥蓋與罩帽、鋼彈簧與 2Cr13 調整螺栓。工作壓力涵蓋 PN1.6 至 PN4.0 與 Class 150 至 Class 300，端接 NPT、RF 或 RTJ。設計依 API 520/521/526/527 洩放系列與 ASME 25.3，面距依 ASME B16.10、EN 558-1 或 DIN 3202，法蘭依 ASME B16.5、DIN 2543/2545 或 EN 12627，測試依 API 598 / DIN 323。啟閉等級構成選擇框架：微啟僅開啟孔徑的 1/24（微啟結構為喉部的 1/40-1/20），排放面積隨閥盤位置變化、排量有限，對照 1/12 的高啟與簾面積不再有意義的全啟。ASME 規範窗口限制動作——鍋爐閥 3% 內開啟、4% 內關閉，Section VIII 閥 10% 與 7%——且在可壓縮流體上，當入口管壓降（規範限值為整定壓力的 3%，GB 12241 取 3% 與啟閉壓差 1/3 的較小值）超過 7-10% 的啟閉壓差時即開始顫振，這是業界尚未定論的定量穩定性問題。例行檢查應在 75% 整定壓力以上扳動手動開啟桿以防咬死。選型取決於液體對可壓縮任務、PN/Class 區間內的整定壓力，以及內件材料對介質。

屬於安全閥系列

最後更新： 2026-11

請求報價

系列規格

Set-pressure range	0.1 to 1.6 MPa
Nominal valve connection size	DN32–DN150
Valve body material	Cast Iron, WCB, SS304, SS316
Nozzle Materials	2Cr13, SS304, SS316
Disc Materials	2Cr13, SS304, SS316
End connection types	NPT, RF, RTJ
Service temperature range	-20 to 425°C (ductile iron ≤300°C, WCB ≤425°C)
Design standards	ASME 25.3, API 520, API 521, API 526, API 527
Inspection and pressure-test standards	API 598, DIN 323
Face-to-face dimensional standard	ASME B16.10, EN558-1, DIN 3202
adjusting ring materials	2Cr13, SS304, SS316
guide sleeve materials	2Cr13, SS304, SS316
Bonnet material	Carbon Steel
spring materials	Steel
Stem material	2Cr13, SS304, SS316
adjusting bolt materials	2Cr13
cap materials	Carbon Steel
Working pressure (source-defined)	PN1.6, PN2.5, PN4.0, Class 150 to Class 300
Flange standards	ASME B16.5, DIN 2543, DIN 2545, EN 12627
low lift definition limited opening	Low lift: the disc lifts only 1/24th of the bore diameter, the discharge area is determined entirely by disc position, and capacities are much lower than full- or high-lift valves of the same size
high lift definition between low and full	High lift (the intermediate execution) lifts at least 1/12th of the bore diameter, where the curtain area - and ultimately disc position - still determines the discharge area
full lift definition curtain area	Full lift: the disc lifts sufficiently that the curtain area no longer influences the discharge area - the defining contrast with low-lift valves
asme code opening blowdown windows	ASME code windows: ASME I boiler valves open within 3% overpressure and close within 4%; ASME VIII pressure-vessel valves open within 10% overpressure and close within 7%
proportional action liquid systems	Proportional-type action is characteristic of relief valves used in liquid systems; this proportionate behaviour is what low-lift executions trade against the full-bore pop
easing lever periodic manual lift	Standard safety valves are generally fitted with an easing lever for manual lifting to confirm operation at pressures above 75% of set pressure, done as part of routine safety checks or maintenance to prevent seizing
micro lift opening height gb definition	Chinese micro-lift (微启式) definition: opening height below 1/4 of the flow diameter, typically 1/40-1/20, with proportional action
micro lift used for liquid media	Micro-lift valves are mainly used for liquid service, and only occasionally for very small gas discharge
micro lift throat area definition mihana	Japanese manufacturer definition: micro-lift valves open a small height, usually 1/40-1/20 of the seat (throat) diameter, with the seat flow area only slightly larger than the throat area
inlet pressure drop 3pct rule	Code rule: inlet piping pressure drop between the protected equipment and the safety valve must not exceed 3% of set pressure (API 520; GB 12241 takes the lesser of 3% of set pressure and 1/3 of the maximum blowdown)
chatter mechanism inlet drop vs blowdown	Chatter mechanism on compressible fluids: blowdown is typically 7-10% of set pressure, and when the inlet pressure drop exceeds the blowdown the valve chatters or flutters
inlet pressure drop stability engineering	Stability during relief is a key valve characteristic: inlet piping pressure drop is a recognized major factor behind disc chatter or flutter, but how to evaluate its influence quantitatively remains unsettled
adjusting ring	2Cr13, SS304, SS316
guide sleeve	2Cr13, SS304, SS316
adjusting bolt	2Cr13
end connection	NPT, RF, RTJ
end connection dimension	ASME B16.5, DIN 2543, DIN 2545, EN 12627

範圍與來源備註

gas service positioning	Gas-service positioning: the page presents low-lift as liquid-dominant (proportional action, mainly liquid service, gas only at very small discharge), while the spec list carries the same API 520/526/527 design standards as the full-lift page; gas applications should be scoped to small discharge or referred to full-lift.