Common faults and treatment methods of differential pressure flowmeter
1. Indicates zero or very little movement. The reasons are:
(1) The balance valve is not fully closed or leaks;
(2) The high and low pressure valves at the root of the throttling device are not opened;
(3) The valve and pipeline between the throttling device and the differential pressure gauge are blocked;
(4) The steam pressure guiding tube is not completely condensed;
(5) The liner between the throttling device and the process pipeline is not tight;
(6) Internal failure of the differential pressure gauge.
The corresponding processing method is:
(1) Close the balance valve, repair or replace it with a new one;
(2) open;
(3) Flush the pipeline, repair or replace the valve;
(4) Turn on the watch after it is completely condensed; (5) Tighten the bolts or change the gasket;
(6) Check and repair.
2. The indication is below zero. The reasons are:
(1) Reverse connection of high and low pressure pipelines;
(2) The signal line is reversed;
(3) Serious leakage or rupture of the high-pressure side pipeline.
The corresponding processing method is:
(1) Check and connect correctly;
(2) Check and connect correctly;
(3) Change parts or pipes.
3. The indication is low. The reasons are:
(1) The pipeline on the high pressure side is not tight;
(2) The balance valve is not tight or closed tightly;
(3) The air in the high-pressure side pipeline is not exhausted;
(4) The zero position of the differential pressure gauge or the secondary instrument is out of adjustment or displaced;
(5) The throttling device and the differential pressure gauge are not matched and do not meet the design requirements.
The corresponding processing method is:
(1) Check and eliminate leakage;
(2) inspection, closure or repair;
(3) Exhaust the air;
(4) Check and adjust;
(5) Replace the supporting differential pressure gauge according to the design requirements.
4. The indication is too high. The reasons are:
(1) The pipeline on the low pressure side is not tight;
(2) Air accumulated in the low-pressure side pipeline;
(3) The pressure of steam, etc. is lower than the design value;
(4) Zero drift of differential pressure gauge;
(5) The throttling device and the differential pressure gauge are not matched and do not meet the design requirements.
The corresponding processing method is:
(1) Check and eliminate leakage;
(2) Exhaust 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) Serious leakage of the low-pressure side pipeline;
(3) The signal line is disconnected.
The corresponding processing method is:
(1) Replace the differential pressure gauge with a suitable range;
(2) Exclude leakage;
(3) Check and repair.
6. The indication changes slowly when the flow rate changes. The reasons are:
(1) The connecting pipeline and valve are blocked;
(2) There is a fault inside the differential pressure gauge.
The corresponding processing method is:
(1) Flush the pipeline and dredge the valve;
(2) Check and exclude.
7. The indication fluctuates greatly. The reasons are:
(1) The flow parameter itself fluctuates too much;
(2) The load cell is sensitive to parameter fluctuations.
The corresponding processing method is:
(1) Properly close the high and low pressure valves;
(2) Properly adjust the damping effect.
8. The instruction does not move. The reasons are:
(1) The anti-freezing facilities fail, and the hydraulic pressure in the differential pressure gauge and pressure guiding pipe freezes;
(2) The high and low pressure valves are not open.
The corresponding processing method is:
(1) Strengthen the effect of antifreeze facilities;
(2) Open the high and low pressure valves.
