Help needed: inaccurate readings from a pressure transmitter
Thread Content
Dear colleagues, there is a pressure transmitter installed at the outlet of the plunger pump. The normal operating pressure is between 28 and 30 MPa. Everything was normal before the pump was shut down for maintenance. After the maintenance, the current and frequency associated with the pump’s operation were as expected, but the pressure indicated by the pressure transmitter did not match these values, with a significant difference. During the maintenance, only the plunger pump was repaired; no other electrical components were altered. I would like to ask everyone: where could the problem lie? Thank you
Check if the wiring of the pressure transmitter is loose
Remove the pressure transmitter and apply pressure using a calibration bench to see if the output signal matches the actual pressure. If not, adjust the pressure transmitter; another possibility is to check whether the pressure conduit is unobstructed
Because it was normal before the maintenance, but there were problems after it was shut down for maintenance. In such cases, it is necessary to carefully check whether the transmitter and its associated wiring connections are in good condition, as well as to verify that there is no blockage in the sampling valves and pressure guide tubes.
First, calibrate the pressure transmitter and the pressure gauge; if they still don’t match, the problem lies with the pump or the piping, so investigate each one separately...
Does the pressure displayed by the pressure transmitter not match the current and frequency of your pump? It’s likely that the capacity of your pump has changed after the maintenance, so it no longer matches the level before the machine was shut down
However, the production output matches the pump frequency and current.
Close the valve, vent to atmosphere, and check whether the zero point is zero. Use a pressure gauge to roughly calibrate it. I think what was said on the 6th floor makes sense!