Common faults, causes and troubleshooting methods of differential pressure flowmeters

1. Indicate zero or small movement. The reasons are: (1) the balance valve is not fully closed or leaks; (2) the high and low pressure valve at the root of the throttling device is not opened; (3) the valve and pipeline between the throttling device and the differential pressure gauge are blocked; (4) the steam conduction The pressure pipe is not completely condensed; (5) The liner between the throttling device and the process pipeline is not tight; (6) The internal failure of the differential pressure gauge. The corresponding treatment methods are: (1) Close the balance valve, repair or replace it; (2) Open; (3) Flush the pipeline, repair or replace the valve; (4) Open the meter after it is completely condensed; (5) Tighten the bolt Or change the pad; (6) Check and repair. 2. The indication is below zero. The reasons are: (1) High and low pressure pipelines are reversely connected; (2) Signal lines are reversely connected; (3) High-pressure side pipelines are severely leaked or ruptured. The corresponding treatment methods are: (1) Check and connect correctly; (2) Check and connect correctly; (3) Replace parts or pipes. 3. The indication is low. The reasons are: (1) The high-pressure side pipeline is not tight; (2) The balance valve is not tight or not tightly closed; (3) The air in the high-pressure side pipeline is not drained; (4) The differential pressure gauge or the zero position of the secondary instrument Maladjustment or displacement; (5) The throttling device and the differential pressure gauge are not matched and do not meet the design requirements. The corresponding treatment methods are: (1) check and eliminate leakage; (2) check, shut down or repair; (3) drain the air; (4 check and adjust; (5) replace the matched differential pressure gauge according to the design regulations. 4 , The indication is too high. The reasons are: (1) the low-pressure side pipeline is not tight; (2) the low-pressure side pipeline is trapped with air; (3) the pressure of steam, etc. is lower than the design value; (4) differential pressure gauge zero drift (5) The throttling device and the differential pressure gauge are not matched and do not meet the design regulations. The corresponding treatment methods are: (1) Check and eliminate leakage; (2) Drain the air; (3) Correct according to the actual density; (4) ) Check and adjust; (5) Replace the supporting differential pressure gauge as required. 5. The indication exceeds the upper limit of the scale. The reasons are: (1) The actual flow exceeds the design value; (2) The low-pressure side pipeline is seriously leaking; (3) Signal The line is disconnected. The corresponding treatment methods are: (1) Change to a differential pressure gauge with a suitable range; (2) Eliminate leakage; (3) Check and repair. 6. When the flow rate changes, the indication change is slow. The reasons are: ( 1) The connecting pipelines and valves are blocked; (2) There is a fault in the differential pressure gauge. The corresponding treatment methods are: (1) Flush the pipeline and dredge the valve; (2) Check and eliminate. 7. The indication fluctuates greatly. The reason It is: (1) The flow parameter itself fluctuates too much; (2) The pressure measuring element is more sensitive to the parameter fluctuation. The corresponding treatment methods are: (1) The high and low pressure valve is properly closed; (2) The damping effect is appropriately adjusted. 8. The indication does not move. The reasons are: (1) the antifreeze facility fails, and the differential pressure gauge and the hydraulic pressure in the pressure guiding tube are frozen; (2) the high and low pressure valve is not opened. The corresponding treatment methods are: (1) strengthen the effect of the antifreeze facility; (2) Open the high and low pressure valve.