Describe the " in the vacuum valve

The first step: the internal leakage of the gate valve, the energy consumption is first "know". The device does energy consumption calculation every day. Today, compared with yesterday, the raw materials are the same. If the yield is reduced, in addition to eliminating the process and instrumentation reasons, it may be judged that there may be leakage of the gate valve, resulting in increased energy consumption.

        The second step: the thermometer detects "indispensable". The gate valve leaks, and the adjacent subsequent pipelines are detected by the thermometer to detect a significant increase or decrease in temperature.

        The third step: the stethoscope "follow up". We judged the internal leakage of the gate valve through the first step and the second step method, but it is still not fully confirmed. At this time, the "stethoscope" is very important. You can choose the screwdriver as the "stethoscope", the end of the screwdriver head is perpendicular to the pipeline, and the other end is close to your own ear. Listen carefully to whether there is a "sting" abnormal sound in the pipeline. If so, you can judge that the gate valve is leaking.

        According to these three steps, it is basically possible to accurately determine whether the gate valve is leaking.

        In addition, attach a temperature in the end how to identify the endoleak.

        The method for judging the inner leakage of the valve is: after the valve is closed for 4-6 hours, the infrared temperature measuring instrument is used to measure the metal temperature of the valve stem (near the valve body) or 150 mm downstream of the valve body, and if it is greater than 70 ° C, it is considered as "internal leakage". ". This method of judging is applicable to most internal leakage valves, but in actual work, we have encountered the following special cases: side-by-side intervention of the draining or draining door of the water main pipe, when the rear valve position is close In the case of the mother pipe, as long as any branch valve in the pipeline leaks inside, the temperature of other valves will rise to exceed 70 °C, such as boiler blowdown valve, superheated steam and so on. Therefore, the internal leakage of these valves must be determined in other ways. Generally, the temperature of the front wall of the door is measured, and the temperature of the valve stem is used to determine the internal leakage.

        Valve internal leakage determination standard (temperature) medium temperature

        Serious leaking of pipe wall temperature after trapping valve

        >500°C
        >250°C and the temperature difference from the front wall is less than 50°C
        >200°C and the temperature difference from the front wall is less than 50°C
        >150°C and the temperature difference from the front wall is less than 50°C
        >120°C and the temperature difference from the front wall is less than 50°C

        General endoleak

        >200°C and the temperature difference from the front wall is less than 80°C
        >150°C and the temperature difference from the front wall is less than 80°C
        >100°C and the temperature difference from the front wall is less than 80°C
        >80°C and the temperature difference from the front wall is less than 50°C

        leakage

        >200°C and the temperature difference from the front wall is greater than 50°C
        >150°C and the temperature difference from the front wall is greater than 50°C
        >100°C and the temperature difference from the front wall of the door is greater than 50°C

        >80°C and the temperature difference from the front wall is less than 50°C