閥門作為工業管道系統中控制流體介質的關鍵部件，其密封性能直接關系到生產安全與運行效率。在實際應用中，閥門泄漏問題可能由密封面損傷、閥桿密封失效或材質缺陷等多種因素引發。為精準定位泄漏點并評估泄漏程度，行業已發展出多種檢測技術，以下將系統介紹這些方法的原理與操作要點。

　　As a key component for controlling fluid media in industrial pipeline systems, the sealing performance of valves directly affects production safety and operational efficiency. In practical applications, valve leakage problems may be caused by various factors such as damage to the sealing surface, failure of the valve stem seal, or material defects. To accurately locate the leakage point and evaluate the degree of leakage, the industry has developed various detection technologies. The following will systematically introduce the principles and operational points of these methods.

　　氣泡檢測法是基礎檢測手段之一，適用于低壓工況下的閥門外漏檢測。檢測時需將閥門浸入水中或對閥體表面噴涂肥皂水溶液，通過觀察泄漏點形成的氣泡判斷泄漏位置。此方法對微小泄漏的檢測靈敏度可達1×10^-3 Pa·m3/s，但受限于操作環境濕度，且無法量化泄漏速率。

　　Bubble detection method is one of the basic detection methods, suitable for valve leakage detection under low pressure conditions. During the inspection, the valve should be immersed in water or sprayed with soap solution on the surface of the valve body. The leakage location can be determined by observing the bubbles formed at the leakage point. The sensitivity of this method for detecting small leaks can reach1×10^-3 Pa·m3/s， But limited by the humidity of the operating environment and unable to quantify the leakage rate.

　　壓力變化檢測法通過監測系統壓力變化來評估內漏情況。具體操作時，關閉閥門并隔離上下游管道，記錄壓力表讀數隨時間的變化曲線。根據理想氣體狀態方程可推算泄漏量，該方法對緩慢泄漏的檢測周期通常需持續24小時以上，適用于定期檢驗場景。

　　The pressure change detection method evaluates internal leakage by monitoring system pressure changes. During the specific operation, close the valve and isolate the upstream and downstream pipelines, and record the curve of the pressure gauge reading over time. According to the ideal gas state equation, the leakage rate can be calculated. This method usually requires a detection cycle of more than 24 hours for slow leaks and is suitable for regular inspection scenarios.

　　聲學檢測法利用泄漏產生的超聲波信號進行定位。檢測儀器通過高靈敏度傳感器捕捉20kHz以上的超聲波，經濾波放大后轉換為可聽聲信號。實驗數據顯示，該技術對0.1mm微孔泄漏的檢測距離可達5米，但需注意排除流體噪聲干擾，通常在夜間或低背景噪聲環境下進行。

　　Acoustic detection method uses ultrasonic signals generated by leaks for localization. The detection instrument captures ultrasonic waves above 20kHz through a high-sensitivity sensor, filters and amplifies them, and converts them into audible sound signals. Experimental data shows that this technology can detect leaks from 0.1mm micropores up to a distance of 5 meters, but attention should be paid to eliminating fluid noise interference, which is usually carried out at night or in low background noise environments.

　　紅外熱成像檢測法基于泄漏介質與環境的溫差成像原理。當高壓氣體泄漏時，節流效應導致局部溫度驟降，紅外熱像儀可捕捉0.1℃的溫差變化。該方法對蒸汽閥門的檢測效果尤為顯著，但需注意環境風速對溫度場的影響，建議檢測時風速低于2m/s。

　　The infrared thermal imaging detection method is based on the principle of temperature difference imaging between the leaked medium and the environment. When high-pressure gas leaks, the throttling effect causes a sudden drop in local temperature, and the infrared thermal imager can capture a temperature difference of 0.1 ℃. This method has a particularly significant detection effect on steam valves, but attention should be paid to the influence of environmental wind speed on the temperature field. It is recommended that the wind speed during detection be below 2m/s.

　　氦質譜檢漏法是精密檢測的首選方案，檢測靈敏度可達1×10^-9 Pa·m3/s。操作時在閥門一側充入氦氣混合氣體，另一側用質譜儀檢測氦離子濃度。該方法需配備真空泵組，單點檢測時間約3分鐘，適用于核電、航天等高安全等級領域。

　　Helium mass spectrometry leak detection method is the preferred solution for precision detection, with a detection sensitivity of up to 1 × 10 ^ -9 Pa · m3 /s. Fill one side of the valve with helium gas mixture during operation, and use a mass spectrometer to detect helium ion concentration on the other side. This method requires a vacuum pump unit and a single point detection time of about 3 minutes, which is suitable for high safety level fields such as nuclear power and aerospace.

　　在實施檢測時，需根據閥門類型、介質特性及工藝要求選擇適宜方法。對于常規維護，氣泡法與壓力法組合使用可滿足基本需求；關鍵閥門建議采用聲學與熱成像雙重檢測；超標泄漏案例則需啟動氦質譜檢漏程序。檢測周期方面，常開閥門建議每年檢測一次，調節閥等易損件應縮短至半年。

　　When conducting testing, appropriate methods should be selected based on valve type, medium characteristics, and process requirements. For routine maintenance, the combination of bubble method and pressure method can meet basic needs; It is recommended to use acoustic and thermal imaging dual detection for key valves; For cases of excessive leakage, the helium mass spectrometry leak detection program needs to be initiated. In terms of inspection cycle, it is recommended to inspect normally open valves once a year, and shorten the inspection of vulnerable parts such as regulating valves to six months.

　　值得注意的是，檢測數據需結合閥門設計參數綜合研判。例如，API 622標準規定軟密封閥門允許的最大泄漏率為0.1%泡痕/分鐘，而硬密封閥門執行API 598標準，殼體試驗泄漏量不得超過50cm3/分鐘。檢測報告應詳細記錄環境溫濕度、介質壓力等邊界條件，確保檢測結果的可追溯性。

　　It is worth noting that the detection data needs to be comprehensively analyzed and judged in conjunction with the valve design parameters. For example, the API 622 standard stipulates that the maximum allowable leakage rate for soft sealed valves is 0.1% bubble marks per minute, while hard sealed valves comply with the API 598 standard, and the shell test leakage rate shall not exceed 50cm3/minute. The testing report should record in detail the boundary conditions such as environmental temperature and humidity, medium pressure, etc., to ensure the traceability of the testing results.

　　隨著技術發展，基于機器視覺的智能檢測系統正逐步應用。該系統通過高速攝像機捕捉泄漏瞬間的介質噴射形態，結合圖像處理算法可自動計算泄漏孔徑及流量。某石化企業實際應用顯示，該技術使泄漏檢測效率提升40%，誤報率降低至0.5%以下。

　　With the development of technology, intelligent detection systems based on machine vision are gradually being applied. The system captures the medium jet shape at the moment of leakage through a high-speed camera, and combines image processing algorithms to automatically calculate the leakage aperture and flow rate. The actual application of this technology in a petrochemical enterprise shows that it improves the efficiency of leak detection by 40% and reduces the false alarm rate to below 0.5%.

　　閥門泄漏檢測需遵循“預防為主、檢測為輔”的原則。通過建立閥門健康檔案，記錄每次檢測數據與維修記錄，可實現全生命周期管理。對于高頻泄漏閥門，建議采用根因分析方法，從設計選型、安裝工藝、操作規程等多維度制定改進方案，而非簡單重復檢測維修。

　　Valve leakage detection should follow the principle of "prevention first, detection as a supplement". By establishing a valve health record, recording each inspection data and maintenance record, full lifecycle management can be achieved. For high-frequency leakage valves, it is recommended to use root cause analysis method to develop improvement plans from multiple dimensions such as design selection, installation process, and operating procedures, rather than simply repeating testing and maintenance.

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