Instrumentation: [Weekly Question] Week 16 of 2011: Startup steps for a differential pressure transmitter for flow measurement

1. Fill with cooling liquid. 2. First, open the balance valve. 3. Then, open the secondary valve. 4. Close the balance valve

This post was last edited by denghl on 2012-12-21 08:22. Operating steps for the initial startup after installing a differential pressure transmitter for measuring steam flow: 1) Check whether all valves, pressure guiding tubes, union joints, etc. are firmly connected； 2) Check whether the secondary valve and the drain valve are closed, and whether the balance valve is closed ； 3) Open the valve slightly once, then check the pressure guide tube, valve, union, etc.; if there is no leakage, open the valve fully ； 4) Open the drain valve, discharge the waste fluid, and then close the drain valve ； & p0 h$ ]+ }1 U* D1 d5 |6 \ 5) Loosen the screw plug in the differential pressure chamber to remove the air from it ； * U, P- {. ]$ b/ A- s 6) The differential pressure transmitter can be started only after the pressure guiding tube is filled with condensed water ； 7) To start the differential pressure transmitter, follow these steps: open the positive pressure valve, close the balance valve, and open the negative pressure valve. At this point, the instrument has finished starting up.

1. Pour in the isolation fluid with the balance valve open: Open the positive pressure valve, close the balance valve, and open the negative pressure valve

This post was last edited by denghl on 2012-12-20 at 18:00: 1. Fill with condensate fluid. 2. First, open the balance valve. 3. Then, open the shut-off valve on the positive pressure side and the shut-off valve on the negative pressure side in sequence. 4. Close the balance valve

After confirming that all the instrument valves newly installed on this instrument are in the closed state (with condensate already filled), 1. First, open the balance valve. 2. Then, open the positive pressure valve. 3. Open the drain valves for the positive pressure chamber and the negative pressure chamber. 4. Close the drain valves for the positive pressure chamber and the negative pressure chamber. 5. Close the balance valve. 6. Open the negative pressure valve

This post was last edited by denghl on 2012-12-21 08:22. The following steps should be followed: 1. Check whether all valves, pressure guide tubes, union joints, etc. are firmly connected； 2. Check whether the secondary valve and the drain valve are closed, and whether the balance valve is open ； 3. Open the valve slightly once, then check the pressure guide tube, valve, union, etc.; if there is no leakage, open the valve fully ； 4. Open the drain valves separately, drain the waste fluid, and then close the drain valves ； 5. Loosen the plug in the differential pressure chamber to remove the air from it ； 6. The differential pressure transmitter can be activated only after the pressure guiding pipe is filled with condensed water ； 7. To start the differential pressure transmitter, it should be done in the order of opening the positive pressure valve, closing the balance valve, and opening the negative pressure valve.

1) Fill with isolation fluid. 2) Close the positive and negative pressure chambers as well as the balance valve. 3) Open the needle valve for steam introduction. 4) Open the drain valve and exhaust valve of the three-valve assembly. 5) Close the drain and exhaust valves. 6) Open the positive pressure chamber. 7) Close the balance valve. 8) Open the negative pressure chamber. OK

This post was last edited by denghl on 2012-12-21 08:23. After calibration and installation, first flush the pipe and fill it with condensate； Then close the valves on the positive and negative pressure sides, and open the balance valve ； During operation, first open the valve on the positive pressure side or the negative pressure side, close the balance valve, then open the valve on the negative pressure side or the positive pressure side, and the operation is complete. Note: It is strictly prohibited to have the three-valve assembly in the open position during operation~

Re* it, haven’t used it in a long time

This post was last edited by denghl on 2012-12-21 08:23. Reply 1# Baghdad: (1) Check whether all valves, pressure guiding pipes, unions, etc. are firmly connected. (2) Ensure that the secondary valve and the drain valve are closed, as well as the balance valve. (3) Open the primary valve slightly, then check the valves, pressure guiding pipes, unions, etc.; if there is no leakage, open the primary valve fully. (4) Open the drain valve one by one, drain the fluid, and then close the drain valves. (5) Loosen the screw plug in the differential pressure chamber to remove any air from it. (6) The differential pressure transmitter can be started only after the pressure guiding pipes are filled with condensate water. (7) To start the differential pressure transmitter, follow these steps: open the positive pressure valve, close the balance valve, and open the negative pressure valve. At this point, the instrument has been fully started up.