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experts: there is a trick to judge the leakage of vacuum valve
release time:2018/12/15
step 1: gate valve leakage, energy consumption accounting "know". the energy consumption accounting done by the device every day is the same as that of yesterday. if the yield drops, i will preliminarily judge that there may be leakage in the gate valve, resulting in the increase of energy consumption.
step 2: temperature measuring instrument detection "indispensable". gate valve leakage, adjacent to the follow-up pipeline through the thermometer detection temperature will significantly increase or decrease.
step 3: the stethoscope "catches up." we determine the gate valve leakage through the first step, the second step method inspection, but not fully confirmed, then "stethoscope" detection is very important. can choose screwdriver to be "stethoscope", screwdriver head end and pipeline perpendicular, another end clings to his ear closely, listen carefully whether there is "prickle" abnormal sound in the pipeline, if there is, can judge here gate valve leakage.
according to these three steps, basically can accurately determine whether the gate valve leakage!
in addition: attached is a temperature is exactly how to identify the internal leakage.
method determining leakage in the valve is: 4-6 hours after the valve closed, measured with infrared thermometer table (near the body) or downstream of the valve stem, 150 mm metal temperature, such as more than 70 ℃, was identified as "leak". the judgment method for the majority of the leak valve is applicable, but in the practical work, we met some special cases are the following: access hydrophobic side by side, put the jellyfish tube of watergate or discharge door, when the last line of the valve position near the mother tube, as long as any branch within the valve leakage in pipeline, other valve temperature will rise to more than 70 ℃, such as boiler blowdown valve, superheated steam drain, etc. therefore, the determination of the internal leakage of these valves should also be used in other ways, the general measurement of the door wall temperature or a door valve stem temperature to determine the internal leakage.
valve internal leakage criteria (temperature) medium temperature
the temperature of the pipe wall behind the trap is seriously leaking
> 500 ℃
> 250 ℃, and in front of the tube wall temperature is less than 50 ℃
> 200 ℃, and in front of the tube wall temperature is less than 50 ℃
> 150 ℃, and in front of the tube wall temperature is less than 50 ℃
> 120 ℃, and in front of the tube wall temperature is less than 30 ℃
general internal leakage
> 200 ℃, and in front of the tube wall temperature is less than 80 ℃ > 150 ℃, and in front of the tube wall temperature is less than 80 ℃ > 100 ℃, and in front of the tube wall temperature is less than 80 ℃ > 80 ℃, and in front of the tube wall temperature is less than 50 ℃
leakage
> 200 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 150 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 100 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 80 ℃, and in front of the tube wall temperature is greater than 50 ℃
400 ℃ to 500 ℃
300 ℃ to 400 ℃
150 ℃ to 300 ℃
step 2: temperature measuring instrument detection "indispensable". gate valve leakage, adjacent to the follow-up pipeline through the thermometer detection temperature will significantly increase or decrease.
step 3: the stethoscope "catches up." we determine the gate valve leakage through the first step, the second step method inspection, but not fully confirmed, then "stethoscope" detection is very important. can choose screwdriver to be "stethoscope", screwdriver head end and pipeline perpendicular, another end clings to his ear closely, listen carefully whether there is "prickle" abnormal sound in the pipeline, if there is, can judge here gate valve leakage.
according to these three steps, basically can accurately determine whether the gate valve leakage!
in addition: attached is a temperature is exactly how to identify the internal leakage.
method determining leakage in the valve is: 4-6 hours after the valve closed, measured with infrared thermometer table (near the body) or downstream of the valve stem, 150 mm metal temperature, such as more than 70 ℃, was identified as "leak". the judgment method for the majority of the leak valve is applicable, but in the practical work, we met some special cases are the following: access hydrophobic side by side, put the jellyfish tube of watergate or discharge door, when the last line of the valve position near the mother tube, as long as any branch within the valve leakage in pipeline, other valve temperature will rise to more than 70 ℃, such as boiler blowdown valve, superheated steam drain, etc. therefore, the determination of the internal leakage of these valves should also be used in other ways, the general measurement of the door wall temperature or a door valve stem temperature to determine the internal leakage.
valve internal leakage criteria (temperature) medium temperature
the temperature of the pipe wall behind the trap is seriously leaking
> 500 ℃
> 250 ℃, and in front of the tube wall temperature is less than 50 ℃
> 200 ℃, and in front of the tube wall temperature is less than 50 ℃
> 150 ℃, and in front of the tube wall temperature is less than 50 ℃
> 120 ℃, and in front of the tube wall temperature is less than 30 ℃
general internal leakage
> 200 ℃, and in front of the tube wall temperature is less than 80 ℃ > 150 ℃, and in front of the tube wall temperature is less than 80 ℃ > 100 ℃, and in front of the tube wall temperature is less than 80 ℃ > 80 ℃, and in front of the tube wall temperature is less than 50 ℃
leakage
> 200 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 150 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 100 ℃, and in front of the tube wall temperature is greater than 50 ℃ > 80 ℃, and in front of the tube wall temperature is greater than 50 ℃
400 ℃ to 500 ℃
300 ℃ to 400 ℃
150 ℃ to 300 ℃