Problems with orifice plate flowmeters
Thread Content
There is a orifice plate flow meter, with variable frequency control for the transfer pump. The frequency conversion control was around 50, with a flow rate of 300 standard liters per hour. After flushing the pipes in the process, the frequency conversion control is still around 50, but there is no flow rate display. The meter head was disassembled (and has now been replaced); the orifice plates are in good condition with no scratches on them. The frequency conversion control is around 70, and the flow rate shows around 90; the process conditions remain the same as before flushing. What is the reason for such a large change in traffic before and after? I suspect that this is indeed the actual process flow rate
The flange of the orifice plate has annular groove channels formed together with the orifice plate; should it be checked whether these channels are blocked as a result of purging? Generally, the purge procedure requires that the orifice plate be removed, which not only affects the quality of the purge but also makes it easy for dust to accumulate. For reference.
The orifice plate itself generally does not have problems. Mainly, the pressure tap needs to be checked.
1. Check the pressure guide tube and transmitter section. 2. Check the orifice plate and its orientation. 3. Determine whether there are valves or bypass systems for flow restriction or diversion before and after the flow meter. 4. Check for process-related issues or problems with the pump
It is necessary to carefully check whether the pressure tapping holes on both sides of the orifice plate are blocked; if these holes are blocked, it will cause changes in the pressure difference, affecting the calculations.
Are there control valves on the pipeline? If so, what parameters are used to control it?
Check whether the orifice plate is clogged??
When purging pipes, it is necessary to remove the orifice plates to prevent wear caused by sharp edges; also, allow more waste to be discharged for a while
That’s a detail issue that we often overlook in our daily lives! Thank you for sharing!
The positive pressure side might be blocked; the flow rate has decreased significantly compared to before, and it is suspected that there are deposits on the positive pressure side, with the pipeline appearing partially blocked! Use a pressure pump to give it a try and see if the volume can increase
If possible, check the accuracy of differential pressure measurement for the removed headers, and use the elimination method to identify the problem.