Is it possible to calibrate differential pressure transmitter, which is used to measure steam, and we are not going to take it out of the process
Force its value from DCS, then isolate it and remove it, install the spare one, and normalize it, after its reading and mA are stable on its display and on HART, Normalize it from DCS as well, now the system is running smoothly, calibrate the removed transmitter on the test bench.
If there’s a 3 or 5 valve manifold, then the transmitter can be isolated from the process using the manifold valves.
The manifold’s equalizing valve allows for checking zero.
The calibration pressure source can be applied through the plugs or vents on the backside of each process head (3 valve manifold) or through ports on the 5 valve manifold.
For Example: in our system of measure (Metering), we put the stream in mode maintenance and open the connection of DPT, after that we connect our Dead Weight Tester (DWT hydrolic or pneumatic) to the transmitter and do the calibration with weight.(give a pressure and read it in the HMI).