閥門的類型繁多，在廢氣治理行業應用最為廣泛的當屬提升閥、平推閥、蝶閥等，閥門泄漏易造成處理超標、運行成本增加、存在安全風險等一系列問題，因此，降低閥門的泄漏率對項目的安全穩定運行至關重要，下面就幾種密封形式及檢驗方法做簡要介紹。

　　There are many types of valves, and the most widely used ones in the exhaust gas treatment industry are lift valves, push valves, butterfly valves, etc. Valve leakage can easily cause a series of problems such as excessive handling, increased operating costs, and safety risks. Therefore, reducing the leakage rate of valves is crucial for the safe and stable operation of projects. Below are several sealing forms and inspection methods briefly introduced.

　　一、廢氣治理行業常用閥門類型

　　1、 Common valve types in the exhaust gas treatment industry

　　常用的閥門密封類型包括軟密封、硬密封、氣密封等，一般根據不同介質和應用場景選擇合適的密封類型。█?

　　The commonly used types of valve seals include soft seals, hard seals, airtight seals, etc. Generally, the appropriate seal type is selected according to different media and application scenarios. █?

　　1.1 ?軟密封結構軟密封的本質是利用彈性材料（如橡膠、聚四氟乙烯等）的變形能力填充金屬密封副間的間隙，實現零泄漏。其技術優勢與局限主要體現在以下方面：

　　1.1 ? The essence of soft sealing structure is to use the deformation ability of elastic materials (such as rubber, polytetrafluoroethylene, etc.) to fill the gaps between metal sealing pairs, achieving zero leakage. Its technological advantages and limitations are mainly reflected in the following aspects:

　?。?）核心優勢1）高密封性彈性材料受壓后自適應填充表面不平整處，可達到Ⅵ氣泡級密封（泄漏量≤0.15mL/min）。彈性材料的補償能夠降低對閥座/閥瓣加工精度的要求（允許±0.2mm偏差），降低制造成本。2）耐腐蝕性聚四氟乙烯（PTFE）、氟橡膠（FKM）等材料可抵抗酸、堿及有機溶劑腐蝕，壽命較金屬密封提升3-5倍。3）維護便捷性模塊化設計可實現快速更換密封圈（如燕尾卡槽結構），大幅縮短現場維修時間。

　　(1) Core advantage 1) High sealing elastic material can adaptively fill uneven surfaces after compression, achieving VI bubble level sealing (leakage rate ≤ 0.15mL/min). The compensation of elastic materials can reduce the requirements for the machining accuracy of valve seats/discs (allowing ± 0.2mm deviation) and lower manufacturing costs. 2) Corrosion resistant materials such as polytetrafluoroethylene (PTFE) and fluororubber (FKM) can resist acid, alkali, and organic solvent corrosion, and have a lifespan 3-5 times longer than metal seals. 3) The modular design for convenient maintenance enables quick replacement of sealing rings (such as dovetail groove structures), greatly reducing on-site repair time.

　?。?）技術瓶頸1）高溫失效橡膠類材料（硅膠/氟橡膠）在200℃以上發生硬化，壓縮永久變形率＞40%，導致密封性驟降。PTFE雖耐260℃高溫，但冷流性導致長期受壓后塑性變形。2）機械損傷介質含固體顆粒時，軟密封面易被沖刷劃傷。閥板啟閉瞬間高速流體沖擊密封邊緣，可能引發材料疲勞剝落。3）過載壓潰傳統結構無過載保護，關閥力超限將導致彈性材料永久變形。█?

　　(2) Technical bottleneck 1) High temperature failure rubber materials (silicone/fluororubber) harden above 200 ℃, with a compression permanent deformation rate greater than 40%, resulting in a sudden drop in sealing performance. Although PTFE can withstand high temperatures of 260 ℃, its cold flowability causes plastic deformation after long-term compression. 2) When the mechanical damage medium contains solid particles, the soft sealing surface is easily eroded and scratched. The high-speed fluid impact on the sealing edge during the opening and closing of the valve plate may cause material fatigue peeling. 3) Overloading and crushing traditional structures without overload protection will result in permanent deformation of the elastic material if the closing force exceeds the limit. █?

　　1.2 ?硬密封結構

　　1.2 ? Hard sealing structure

　　硬密封依賴金屬精密加工與表面強化，解決軟密封的耐壓瓶頸：（1）三偏心蝶閥設計1）結構特征閥桿軸線與密封面雙偏移+錐角偏心，實現閥板旋轉零摩擦接觸。2）自鎖效應錐角小于摩擦角（通常5°~8°），介質壓力越高密封越緊，反向承壓能力達10bar。（2）彈性金屬閥板與表面處理1）采用雙層閥板結構主閥板（例如：316L不銹鋼）+彈性副板（例如：Inconel合金），受壓時副板變形補償密封面不平度。2）表面強化工藝閥板表面滲氮處理。配合面研磨精度≤0.05mm。█?

　　Hard sealing relies on metal precision machining and surface strengthening to solve the pressure resistance bottleneck of soft sealing: (1) Three eccentric butterfly valve design 1) Structural features: Double offset of valve stem axis and sealing surface+cone angle eccentricity, achieving zero friction contact of valve plate rotation. 2) The self-locking effect has a cone angle smaller than the friction angle (usually 5 °~8 °), and the higher the medium pressure, the tighter the seal, with a reverse pressure bearing capacity of up to 10 bar. (2) Elastic metal valve plate and surface treatment: 1) Adopting a double-layer valve plate structure, the main valve plate (such as 316L stainless steel) and the elastic secondary plate (such as Inconel alloy) compensate for the unevenness of the sealing surface when the secondary plate deforms under pressure. 2) Surface strengthening process: nitriding treatment on the surface of the valve plate. The grinding accuracy of the mating surface is ≤ 0.05mm?

　　1.3 ?氣密封結構氣密封

　　1.3 ? Sealed structure with airtight seal

　?。ㄈ绺蓺饷芊猓┦且环N非接觸式密封技術，利用氣體動壓效應在動部件與靜止部件間形成穩定氣膜，實現零泄漏隔離。在閥座內部嵌入環形壓縮空氣腔，通入0.6MPa潔凈空氣，從密封端面微孔噴出形成氣幕屏障。該設計實現：1）動態隔離：阻斷廢氣接觸密封面，減少腐蝕。2）自動補償：氣壓自適應密封面磨損，維持恒定密封比壓。

　　Dry gas seal is a non-contact sealing technology that utilizes the gas dynamic pressure effect to form a stable gas film between moving and stationary components, achieving zero leakage isolation. Insert an annular compressed air chamber inside the valve seat, introduce 0.6MPa clean air, and spray it out from the micro holes on the sealing end face to form an air curtain barrier. This design achieves: 1) Dynamic isolation: blocking exhaust gas from contacting the sealing surface and reducing corrosion. 2) Automatic compensation: The air pressure adapts to the wear of the sealing surface, maintaining a constant sealing pressure ratio.

　　二 、閥門泄漏檢驗方法█??

　　2、 Valve leakage inspection method █??

　　2.1 ?檢驗標準與泄漏等級要求根據GB/T 4213-2024、GB/T 13927-2022等標準規范，閥門泄漏等級分6級（Ⅰ-Ⅵ），RTO/RCO切換閥需滿足Ⅳ級（硬密封）或Ⅵ級（軟密封）█ ?

　　2.1 ? According to the inspection standards and leakage level requirements of GB/T 4213-2024, GB/T 13927-2022 and other standard specifications, the valve leakage level is divided into 6 levels (I-VI), and the RTO/RCO switching valve needs to meet level IV (hard seal) or level VI (soft seal) █?

　　2.2 ?測試介質與壓力設定

　　2.2 ? Test medium and pressure setting

　　（1）介質選擇1）軟密封閥：潔凈空氣/氮氣（Ⅵ級氣泡法）或水（Ⅳ級流量法）；2）自動補償：空氣（Ⅳ級）。（2）測試壓力1）靜態保壓：6-10kPa；2）動態模擬：1.5倍工作壓差（最高≤0.35MPa）。

　　(1) Medium selection 1) Soft seal valve: clean air/nitrogen (VI level bubble method) or water (IV level flow method); 2) Automatic compensation: Air (Level IV). (2) Test pressure 1) Static holding pressure: 6-10kPa; 2) Dynamic simulation: 1.5 times the working pressure difference (maximum ≤ 0.35MPa).

　　三、泄漏率計算與判定Ⅵ級

　　3、 Leakage rate calculation and determination level VI

　?。ㄜ浢芊猓┳畲笤试S泄漏量：3×10-3×Δp×K

　　(Soft seal) Maximum allowable leakage: 3 × 10-3 × Δ p × K

　　Δp：閥前后壓差（kPa）

　　Δ p: pressure difference before and after the valve (kPa)

　　K：泄漏率系數（查表3.1-1）

　　K: Leakage rate coefficient (refer to Table 3.1-1)

　　通過最大允許泄漏量換算氣泡數，實際氣泡數低于換算氣泡數合格，高于則不合格。

　　Convert the number of bubbles based on the maximum allowable leakage rate. If the actual number of bubbles is lower than the converted number, it is qualified. If it is higher than the converted number, it is unqualified.

　　閥門低泄漏的本質，是以結構創新結合材料特性，用冗余設計應對工況突變。在環保要求與能效升級的雙重驅動下，閥門密封技術已從單一部件創新邁向“結構+材料”系統化集成，青島西子環保研究院有限公司研制的提升閥通過特殊的結構及材料優化，將閥門的泄漏率控制在（V級/VI級），有效保證廢氣治理設施的安全達標及穩定長周期運行。

　　The essence of low leakage in valves is to combine structural innovation with material characteristics and use redundant design to cope with sudden changes in operating conditions. Under the dual drive of environmental protection requirements and energy efficiency upgrades, valve sealing technology has moved from single component innovation to "structure+material" systematic integration. The lift valve developed by Qingdao Xizi Environmental Protection Research Institute Co., Ltd. controls the valve leakage rate at (V/VI level) through special structural and material optimization, effectively ensuring the safety compliance and stable long-term operation of exhaust gas treatment facilities.