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로우 리프트 안전밸브

로우 리프트 안전밸브는 시트 직경의 일부만 개방하여 시트면을 따라 측정된 유체 슬립을 방출합니다 — 풀 보어 팝이 이상 상태를 과도하게 넘어서는 액체 계통 및 임무에 적합한 비례 동작입니다. 범위는 스프링 하중 사양으로 주철, WCB, SS304 또는 SS316 바디, 2Cr13, SS304 또는 SS316의 노즐·조정 링·디스크·가이드 슬리브·스텝 세트, 탄소강 보닛 및 캡, 강재 스프링, 2Cr13 조정 볼트입니다. 작동 압력은 PN1.6~PN4.0 및 Class 150~Class 300에 NPT, RF 또는 RTJ 단자입니다. 설계는 ASME 25.3과 함께 API 520/521/526/527 릴리프 시리즈를 따르며, 페이스 투 페이스는 ASME B16.10, EN 558-1 또는 DIN 3202, 플랜지는 ASME B16.5, DIN 2543/2545 또는 EN 12627, 시험은 API 598 / DIN 323입니다. 리프트 등급이 선택을 프레임합니다: 로우 리프트는 보어의 1/24만 개방(마이크로 리프트 사양은 목 1/40~1/20)하여 방출 면적이 디스크 위치를 따르고 용량이 제한되며, 하이 리프트는 1/12, 풀 리프트는 커튼 면적이 무의미해집니다. ASME 코드 창이 동작을 제한합니다 — 보일러 밸브는 3% 이내 개방, 4% 이내 폐쇄, Section VIII 밸브는 10% 및 7% — 압축성 유체에서는 입구 배관 압력 강하(코드 한계 설정 압력의 3%, GB 12241은 3%와 블로우다운의 1/3 중 작은 값)가 7~10% 블로우다운을 초과하면 채터가 시작되며, 이 양적 안정성 문제는 산업계에서 아직 미해결로 남아 있습니다. 정기 점검에서 75% 이상 설정 압력에서 이징 레버를 작동시켜 응착을 방지하십시오. 선정은 액체 대 압축성 임무, PN/Class 밴드 내 설정 압력, 유체에 대한 트림 재질에 따라 결정됩니다.

다음 패밀리에 속함: 안전밸브 패밀리

최종 업데이트: 2026-11

견적 요청

패밀리 사양

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

범위·출처 비고

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.