Common faults and treatment of Differential pressure flow meter

Common faults and treatment of Differential pressure flow meter

Fault phenomenon	Reason	Treatment measures
Indicates zero or very small movement	1. Balance valve is not fully closed or leaking. 2.The stop valve of high pressure side and low pressure side at the root of the throttle device is not opened. 3.The valve and pipeline between throttling device and differential pressure gauge are blocked. 4.The steam tube is not fully condensed. 5.The gasket between throttling device and process piping is not pressed tightly. 6.The differential pressure gauge is faulty.	1. Close balance valve and repair or replace. 2. Open the stop valve of the high pressure side and low pressure side. 3. Flush the pipeline and repair or replace the valve. 4. Open the meter after complete condensation. 5. Tighten bolts or replace pads. 6. Check and repair.
Indicating below zero	1. The pipelines at high pressure side and low pressure side are reverse connected. 2. The signal line is connected reversely. 3. Pipe on the high-pressure side has a serious leak or crack.	1-2. Connect correctly. 3. Replace the part or the pipe.
Indicating is lower than the standard value	1. Pipe on the high-pressure side is not tight. 2. Balance valve is loose or not closed. 3. Air accumulates in the high-pressure side pipe. 4. Zero point of Differential pressure gauge or secondary instrument misalign or displace. 5. Throttling device and differential pressure gauge are not matched.	1. Check and eliminate the leakage. 2. Inspect, close or repair. 3. Exhaust the air completely. 4. Check and adjust. 5. Replace the differential pressure gauge.
Indicating is higher than the standard value	1. Pipe on the low-pressure side is not tight. 2. Air accumulates in the low-pressure side pipe. 3. The vapor pressure is below the design value. 4. Zero point of Differential pressure gauge drifts. 5.Throttling device and differential pressure gauge are not matched.	1. Check and eliminate the leakage. 2. Exhaust the air completely. 3. Supplement the vapor pressure according to the actual density. 4. Check and adjust. 5. Replace the differential pressure gauge.
Indicating have large fluctuation	1. The flow parameters themselves fluctuates too much. 2. Pressure measuring cells are sensitive to parameter fluctuation.	1. Adjust the valve opening of the high pressure side and the low pressure side appropriately. 2. Adjust the damping effect appropriately.
Indicating does not move	1. Antifreeze facilities fail, hydraulic of Differential pressure gauge and pressure tube freezes. 2. Valves of the high pressure side and the low pressure side are not opened.	1. Strengthen the effect of anti-freezing facilities. 2. Open the valves of the high pressure side and the low pressure side