什么是安全閥以及安全閥的用途是什么？（中英文）
什么是安全閥以及安全閥的用途是什么？
What is a safety valve and what is the purpose of a safety valve?
安全閥可以被視為減壓或卸壓裝置。當(dāng)內(nèi)部流體壓力過(guò)高時(shí)，該閥門將打開(kāi)，以防止系統(tǒng)損壞。這些閥門通常用于燃?xì)夂驼羝芫€。在未受保護(hù)的壓力容器或系統(tǒng)中，如果壓力水平超過(guò)安全壓力水平，則可能對(duì)工廠和人員造成災(zāi)難性影響。安全泄壓閥的主要目的是保護(hù)加壓系統(tǒng)免受超過(guò)其設(shè)計(jì)壓力限制的影響。這些閥門設(shè)計(jì)用于自動(dòng)排出任何承壓系統(tǒng)中的氣壓或液體，從而防止壓力過(guò)大并保護(hù)工廠和人員。為了實(shí)現(xiàn)這一切，應(yīng)確保安全閥的尺寸、選擇、安裝正確。
A safety valve can be considered as a pressure reducing or pressure removing device. When there is any excessive internal fluid pressure then this valve would open so that the damage in the system can be prevented. These valves are commonly used in gas and steam lines. In an unprotected pressure vessel or a system if the pressure level exceeds the safe pressure level, then there could be catastrophic effects on both plant and personnel. The major purpose of a safety relief valve is to protect any pressurized system from the effects of exceeding its design pressure limit. These valves are designed to automatically discharge gas pressure or liquid from any pressure-containing system and thus it prevents excessive pressure and protects plants and personnel. In order to fulfill all this, a safety valve should be properly sized, selected, installed, and maintained.
安全閥有哪些特點(diǎn)？
What are the characteristics of the safety valve?
? 這些閥門主要用于可壓縮流體，例如蒸汽或其他氣體
? 只有當(dāng)壓力降至正常壓力時(shí)，安全閥才會(huì)關(guān)閉，否則它將保持全開(kāi)狀態(tài)。
? 在安全閥中，進(jìn)口比出口更小
? 安全閥采用外部閥桿，位于閥體頂部，用作操作檢查。
? These valves are mostly used for compressible fluids such as steam or other gases
? Only if the pressure drops to the normal pressure, the safety valve would close otherwise it would stay fully open.
? In a safety valve, the inlet port is smaller when compared to the discharge port
? An external valve lever is used in the safety valve and it can be seen at the top of the valve body, which is used as an operational check.
安全閥和溢流閥有什么區(qū)別？
What is the difference between the safety valve and the relief valve?
溢流閥會(huì)釋放液體或按比例打開(kāi)閥門，以便維持一定的系統(tǒng)壓力。如果是安全閥，它會(huì)立即快速升壓和減壓。主要區(qū)別在于容量和設(shè)定點(diǎn)。溢流閥會(huì)在超壓情況下釋放壓力，它有一個(gè)操作器，可以發(fā)出控制信號(hào)來(lái)打開(kāi)閥門。安全閥無(wú)需操作員的幫助即可操作。當(dāng)流體壓力增加時(shí)，溢流閥逐漸打開(kāi)，而當(dāng)達(dá)到設(shè)定壓力時(shí)，安全閥完全打開(kāi)。如果系統(tǒng)達(dá)到開(kāi)啟壓力，安全閥將完全打開(kāi)，并且安全閥沒(méi)有像溢流閥那樣的半開(kāi)或半開(kāi)位置。
A relief valve would release the liquid or open the valve in a proportional manner so that it can maintain some system pressure. In the case of a safety valve, it would quickly lift and reduce the pressure instantly. The major difference is in the capacity and set point. The relief valve would relieve pressure in case of overpressure conditions, it has an operator that would give a control signal to open the valve. Safety valves operate without the help of an operator. The relief valve would open gradually as the fluid pressure increases while the safety valve opens fully when the set pressure is reached. The safety valve will open fully if the system achieves the opening pressure and there is no half or semi-open position for a safety valve like the relief valve.
如何選擇安全閥
How to select a safety valve
? 按介質(zhì)分（空氣、氣體、蒸汽、液體）
? 設(shè)定壓力、爆破壓力和泄壓
? 根據(jù)應(yīng)用所需容量
? 必須考慮溫度、背壓、腐蝕性介質(zhì)或環(huán)境等因素
? 根據(jù)經(jīng)營(yíng)特點(diǎn)
? 正常工作壓力是系統(tǒng)在滿負(fù)荷情況下的工作壓力
? 最大允許工作壓力，是正常工作條件下存在的最大壓力
? 設(shè)定壓力，即閥門開(kāi)始提升的壓力
? 過(guò)壓，是超過(guò)設(shè)定壓力的壓力，閥門在此壓力下開(kāi)始升程
? According to the media (air, gas, steam, liquid)
? Set pressure, popping pressure, and relieve pressure
? According to the required capacity for the application
? Factors such as temperature, back pressure, and corrosive media or environment must be considered
? According to the operational characteristics
? Normal working pressure is the operating pressure of the system under full load
? Maximum allowable working pressure, it is the maximum pressure existing normal operating conditions
? Set pressure, it is the pressure at which the valve starts to lift
? Overpressure, it is the pressure that exceeds the set pressure and the valve starts to lift in this pressure
什么是安全泄壓閥
What is a safety relief valve
安全泄壓閥廣泛應(yīng)用于大多數(shù)工藝設(shè)備中。這些閥門可用作泄壓閥或安全閥。這些閥門可在氣體和蒸汽系統(tǒng)中用作安全閥，也可在液體系統(tǒng)中用作泄壓閥。
Safety relief valves are widely used in most of the process equipment. These valves can be used as either a relief valve or a safety valve. These valves can be used in gas and vapor system as safety valves and they can also be used as a relief valve in a liquid system.
壓力安全閥由哪些部件組成
What are the components of a pressure safety valve
上圖為常規(guī)壓力安全閥的主要部件
蓋子 – 它是安全閥的頂部部分，覆蓋調(diào)節(jié)螺釘，調(diào)節(jié)螺釘可以通過(guò)螺紋或螺栓連接到閥蓋上。
閥蓋 – 它是閥門的中間部分，里面裝有閥桿、彈簧、彈簧按鈕和導(dǎo)板。該裝置可以是開(kāi)放式或封閉式的。
主體 – 它是最底部的部分，包含閥瓣支架、閥瓣、噴嘴泄壓環(huán)和鎖緊螺母。
調(diào)節(jié)螺釘 – 該裝置用于在規(guī)定的設(shè)定壓力下校準(zhǔn)壓力安全閥
閥桿 – 該裝置正確對(duì)齊組件并將彈簧的動(dòng)力傳遞到閥瓣組件
彈簧和彈簧按鈕 – 彈簧有助于保持閥門關(guān)閉，彈簧按鈕可以均勻分布彈簧力。
提升桿 – 提升桿用于手動(dòng)泄壓
閥瓣和閥瓣支架 – 閥瓣是會(huì)受到過(guò)程壓力影響的設(shè)備，它們?nèi)菀资艿侥p、腐蝕和點(diǎn)蝕
噴嘴 – 噴嘴是過(guò)程流體進(jìn)入閥門的入口。有多種類型的噴嘴可用，它們有全螺紋可拆卸式、半螺紋可拆卸式、半焊接在閥體上、半壓制式可拆卸式。
The above figure shows the major parts of the conventional pressure safety valve
Cap – it is the top part of the safety valve, which covers the adjustment screw this could be threaded or bolted to the bonnet.
Bonnet – it is the middle part of the valve and it houses the stem, spring, spring buttons, and guide plate. This device could be open or closed type.
Body – it is the bottom-most portion and it encloses disc holder, disc, nozzle blow-down ring, and locking nut.
Adjustment screw – This device is used for the calibration of pressure safety valve in a specified set pressure
Stem – This device properly aligns the components and transmits the power of the spring to the disc assembly
Spring and spring buttons – Spring will help to keep the valve closed and the spring button can uniformly distribute the spring force.
Lift lever – Lift lever is used for manual pressure relief
Disc and disc holder – Disc is the device that would be affected by process pressure and they are vulnerable to galling, erosion, and pitting
Nozzle – Nozzle is the entrance by which the process fluid enters into the valve. There are many types of nozzles available they are fully threaded and removable, semi threaded and removable, semi, welded in the valve body, semi pressed and removable.
安全閥是如何構(gòu)造的以及構(gòu)造所用的材料有哪些
How safety valves are constructed and what are the materials used for the construction
有時(shí)安全閥必須在低溫、腐蝕性流體等惡劣條件下工作，因此采用特殊材料進(jìn)行構(gòu)造。壓力閥的承壓部件大多采用青銅、鑄鐵或不銹鋼制成。青銅用于小型螺紋閥門，這些閥門用于低和中級(jí)行業(yè)。高壓閥門采用鑄鋼制成。
安全閥的內(nèi)部部件，如作為運(yùn)動(dòng)部件的主軸或?qū)к?，必須采用不易腐蝕的材料制成。閥座和閥瓣必須能夠耐腐蝕，因此其結(jié)構(gòu)采用不銹鋼。有時(shí)，噴嘴盤采用哈氏合金或蒙乃爾合金等特殊合金制成。
Sometimes safety valves must operate under severe conditions like low temperatures, corrosive fluids, etc. So special materials are used for the construction. Mostly the pressure containing components of the pressure valves are constructed by using bronze, cast iron, or stainless steel. Bronze is used for small screwed valves and these valves are used for the low and medium sectors. Higher pressure valves are constructed by using cast steel.
The internal components of safety valves such as spindle or guides which is the moving part must be constructed by using materials that will not easily corrode. The seats and discs must be able to resist corrosion, so stainless steel is used for their construction. Sometimes nozzle discs are constructed by using special alloys such as Hastelloy or monel.
系統(tǒng)中如何發(fā)生超壓以及系統(tǒng)中出現(xiàn)的嚴(yán)重狀況
How excess pressure takes place in a system and How severe condition arises in a system
? 瞬態(tài)壓力波動(dòng)
? 工廠火災(zāi)暴露
? 熱交換器管故障
? 環(huán)境溫度變化
? 冷卻系統(tǒng)故障會(huì)導(dǎo)致蒸汽膨脹
? 化工廠中不受控制的放熱反應(yīng)
? Transient pressure surge
? Plant fire exposure
? Heat exchanger tube failure
? Ambient temperature changes
? Failure of the cooling system and it would cause the vapor to expand
? Uncontrolled exothermic reactions in a chemical plant
安全泄壓閥如何工作
How does a safety relief valve work
如果壓力升至系統(tǒng)中的設(shè)定壓力以上，閥瓣將開(kāi)始升離其底座。彈簧將開(kāi)始?jí)嚎s，彈簧力也會(huì)增加。因此，只有當(dāng)壓力再次增加時(shí)才會(huì)發(fā)生升程，之后才會(huì)發(fā)生通過(guò)閥門的流動(dòng)。超壓是安全閥以其額定容量泄放之前所需的額外壓力升高。超壓取決于設(shè)定壓力和特定應(yīng)用的標(biāo)準(zhǔn)。安全閥中的閥瓣的布置方式是，壓力稍微高于設(shè)定壓力就會(huì)導(dǎo)致閥門打開(kāi)。當(dāng)系統(tǒng)中的壓力達(dá)到安全水平時(shí)，閥門將返回到關(guān)閉位置。
If the pressure rises above the set pressure in a system, the disc will begin to lift off its seat. The spring will start to compress and the spring force also increases. So the lift will happen only if the pressure is increased again and after that, the flow through the valve occurs. Overpressure is the additional pressure rise needed before the safety valve will discharge at its rated capacity. Overpressure is dependent upon the set pressure and the standard for the particular application. The disc in the safety valve is arranged in a way that a slight increase in pressure than the set pressure could cause the valve to open. When the pressure reaches a safe level in the system the valve would return to its closed position. The disc is arranged for rapid opening in order to achieve this most safety valves have a secondary chamber formed by a shroud, skirt, or hood around the outside diameter of the disc.
安全閥有哪些類型
What are the types of safety valves
常規(guī)安全閥
Conventional safety valve
這種類型的閥門有一個(gè)彈簧外殼，該彈簧外殼通向閥門的排放側(cè)。閥門的操作特性受閥門背壓變化的影響。這是較簡(jiǎn)單的安全閥類型，用于背壓且非常小。
This type of valve, it has a spring housing that is vented to the discharge side of the valve. The operational characteristic of the valve is affected by the changes in the backpressure of the valve. This is the simplest type of safety valve and they are used in the backpressure and are very small.
平衡式安全閥
Balanced safety valve
平衡安全閥能夠借助波紋管或其他設(shè)備消除背壓影響。這些閥門是彈簧加載的安全泄壓閥，當(dāng)排氣系統(tǒng)中的累積背壓百分比允許超過(guò)適用于安全閥的超壓百分比時(shí)安裝這些閥門。平衡式安全閥有活塞式和波紋管式兩種。
Balanced safety valves are capable to remove back pressure effects with the help of bellows or other equipment. These valves are spring-loaded safety relief valves, these valves are installed when the percentage build-up back pressure in the exhaust system is allowed to exceed the percentage overpressure applicable to the safety valve. Balanced safety valves are of two types, piston type, and bellow type.
先導(dǎo)式安全閥
Pilot operated safety valves
先導(dǎo)式安全閥是一種泄壓閥，其主要泄壓裝置是帶有自力式輔助泄壓閥。泄壓裝置由輔助泄壓閥控制。先導(dǎo)式安全閥有隔膜式和活塞式兩種類型。隔膜式用于低壓應(yīng)用。就活塞式閥門而言，它有一個(gè)使用活塞形關(guān)閉裝置的主閥和一個(gè)外部先導(dǎo)閥。
A pilot-operated safety valve is a pressure relief valve, in which the major relieving device is with a self-actuated auxiliary relief valve. The relieving device is controlled by the auxiliary relief valve. Pilot operated safety valves are of two types they are diaphragm and piston type. The diaphragm type is used for low-pressure applications. In the case of the piston-type valve, it has a main valve that uses a piston-shaped closing device and an external pilot valve.
基于噴嘴的安全閥類型
Types of safety valves on the basis of the nozzle
全噴嘴式安全閥
Full nozzle safety valve
在這種類型中，噴嘴是法蘭的凸面部分，用于釋放液體和蒸汽，并且還具有封閉的閥蓋。
In this type the nozzle is the raised face portion of the flange, it is used for liquid and vapor relief and also has a closed bonnet.
半噴嘴式安全閥
Semi nozzle safety valve
這些閥門還用于液體和蒸汽釋放。噴嘴由擰入基座連接的嵌件組成，可以是法蘭連接、焊接端連接或螺紋連接
These valves are also used for liquid and vapor relief. Nozzle consist of insert screwed into base connection can be flanged, weld ended or screwed
底座噴嘴式安全閥
Base nozzle safety valve
在這種類型中，噴嘴由閥門的底座形成，大多數(shù)閥門具有螺紋連接，但也有法蘭或焊接端，這些閥門在百分之二十五的過(guò)壓下完全打開(kāi)，并且具有封閉的閥蓋。
In this type, the nozzle is formed from the base of the valve, mostly these valves have a screwed connection but they are also available in flanged or weld-ended and these valves would fully open at twenty-five percent overpressure and they have closed bonnet.
什么是電動(dòng)安全閥
What is an electromatic safety valve
該閥是壓力開(kāi)關(guān)啟動(dòng)的安全閥，它被設(shè)置為在特定壓力下提升，但常規(guī)安全閥僅在壓力累積后才會(huì)提升。
This valve is a pressure switch initiated safety valve and it is set to lift on a particular pressure but a regular safety valve will only lift after the accumulation of pressure.
安全閥的安裝方法
How to install the safety valve
在工廠調(diào)試過(guò)程中，閥門會(huì)被提升，如果有碎片或污垢，就會(huì)損壞閥座。因此，在安裝安全閥之前應(yīng)沖洗系統(tǒng)，以免異物通過(guò)閥門。閥門必須安裝在不會(huì)積聚灰塵和碎屑的地方。安全閥應(yīng)垂直安裝在壓力容器內(nèi)。閥門入口管道的壓降不得超過(guò)設(shè)定壓力的百分之三。在蒸汽應(yīng)用中，安全閥必須安裝在蒸汽管道上方。不宜安裝在下方，因?yàn)檎羝麜?huì)凝結(jié)，充滿管道，弄濕安全閥閥座的上游側(cè)。
During the plant commissioning procedure, the valve would be lifted and there would be seat damage if there is debris or dirt. So the system should be flushed out before installing a safety valve if done so foreign matter won’t pass through the valve. The valve must be installed in a place where dirt and debris must not collect. The safety valve should be mounted vertically in a pressure vessel. The pressure drop in the valve inlet piping must not exceed more than three percent of the set pressure. In steam applications, the safety valve must be installed above the steam pipe. It should not be installed below because, the steam will condense, fill the pipe, and wets the upstream side of the safety valve seat.
安全閥的故障排除和維護(hù)方法
How to troubleshoot and maintain a safety valve
系統(tǒng)工作壓力不得太接近閥門設(shè)定壓力。安全閥的工作壓力和設(shè)定壓力之間需要有百分之五到百分之十的差異。安全閥不得設(shè)置低于15PSI。根據(jù)容器能夠承受的壓力，它應(yīng)該在20-25的范圍內(nèi)。安全閥不能水平安裝，安全閥只能在垂直位置工作，否則將無(wú)法正常工作。安全閥必須存放在干燥的環(huán)境中并免受天氣影響，直到安裝前才應(yīng)將其從墊木或板條箱中取出。閥門必須保持入口朝下，以防止損壞。安全閥必須進(jìn)行年度定期檢查。如果安全閥安裝在室外，那么它們會(huì)暴露在風(fēng)中，空氣、雪、污垢，因此必須采取某些安全措施。安全閥的入口頸部和閥體必須絕緣，并且絕緣的外部部分必須防風(fēng)雨。安全閥必須需要某些備件，它們是平坦的研磨板、高溫潤(rùn)滑劑、粒度研磨劑。
The system operating pressure must not be too close to the valve set pressure. A safety valve needs a five to ten percent difference between the operating and set pressure. Safety valves must not be set to less than 15PSI. It should be in the range of 20-25 according to the pressure that the vessels could handle. We must not install safety valves horizontally safety valves are meant to work only in a vertical position, if not it won’t work properly. Safety valves must be stored in a dry environment and protected from weather, they should not be removed from the skids or crates until immediately prior to installation. The valve must be kept in a way that the inlet is down so that damage can be prevented. Safety valves must be subjected to an annual periodic inspection. If the safety valves are installed outdoor then they would be exposed to wind, air, snow, dirt, so certain safety features must be done. The inlet neck of the safety valve and the valve body must be insulated and the exterior part of the insulation must be weatherproof. Certain spares must be needed for the safety valve they are flat lapping plate, high-temperature lubricant, a lapping compound of grit size.
安全閥泄漏的原因有哪些
What can be the cause of safety valve leakage
如果底座表面有污垢或水垢，則可能會(huì)發(fā)生泄漏。抬起控制桿即可清除污垢。泄漏大多是在初次制造和測(cè)試后造成的，這種問(wèn)題是由于運(yùn)輸過(guò)程中的損壞而產(chǎn)生的。如果安裝不當(dāng)，可能會(huì)導(dǎo)致閥門泄漏。聚四氟乙烯涂層或管道涂料會(huì)導(dǎo)致閥門泄漏。因此，安裝閥門時(shí)必須進(jìn)行檢查，必須確保螺紋不會(huì)太低，如果螺紋進(jìn)入閥門，它會(huì)粘在閥座表面上并可能導(dǎo)致泄漏。
Leakage can happen if there is dirt or scale sitting on the seating surface. Lifting of the lever can remove the dirt. Mostly the leakage can be caused after the initial manufacture and test, this problem occurs from the damage during transit. If the installation is not proper it can cause valve leakage. Teflon coat or pipe dope can cause valve leakage. So it must be checked when the valve is installed we must ensure that it is not too low on threads if this gets into the valve it can stick on the seating surface and can cause a leak.
安全閥的應(yīng)用有哪些
What are the applications of safety valves
發(fā)電廠和熱交換器循環(huán)
減壓及空氣系統(tǒng)
煉油廠和造紙廠
水、空氣增壓系統(tǒng)
化工廠和制藥廠
離岸應(yīng)用
蒸汽及工業(yè)鍋爐系統(tǒng)
Power plants and heat exchangers cycle
Pressure reduction and air system
Refineries and paper mills
Pressure booster system of water and air
Chemical and pharmaceutical plants
Offshore application
Steam and industrial boiler system
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