Operation steps for the initial startup of a differential pressure transmitter used to measure steam flow rate after installation
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Operation steps for the initial startup of a differential pressure transmitter used to measure steam flow rate: 1) Check whether all valves, pressure guiding tubes, unions, 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, then close the drain valve ； 5) Loosen the screw plug in the differential pressure chamber to remove the air from it ； 6) The differential pressure transmitter can be started only after the pressure guiding pipe 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.
Two small questions: 1. How to determine whether the pressure guiding pipe is filled with condensed water? 2. The operation of closing the balance valve in Step 7 – when was the balance valve opened?
The original state should refer to all valves being in the closed position, with the balance valve having to be opened first before the positive pressure valve or negative pressure valve is opened.
1. Regarding the method you mentioned for determining whether the pressure tap is filled with condensate water, the approach we generally use is as follows: Method one – after waiting for a certain period of time, such as overnight, the pressure tap will cool down naturally and become filled with water. As for exactly how long this takes, it is determined based on experience, taking into account factors such as weather conditions, process conditions, and the installation status of the instrument pressure taps. Method 2: Before putting the gauge in use (that is, when closing a valve), manually fill it with sealant; this is suitable for those pressure transfer pipes that cannot be cooled, such as those with strong heat tracing. 2. The question of when the balance valve opens: Once the instrument is taken out of use, the balance valve remains open. Do you not open the balance valve when you stop using the instrument? I’m not sure if you’re satisfied with my answer; if you have any questions, please let me know.
It is also necessary to pay attention to whether the transmitter value is zero when the balance valve is opened
Question 1: The throttle device is generally installed in a location that facilitates maintenance. Using a circulating water pipe to rinse it is sufficient; there should be no vaporization outside the pipe (as it’s steam). Question 2: Before it is put into use, all the valves at the base are kept closed, as the process requires purging and pressurizing (to protect your instruments)
I personally think there is a problem with the seventh unit. When using a differential pressure transmitter, one should first open the positive pressure valve and the negative pressure valve, and then close the balance valve. Doing this can reduce the erosive force of the pressure difference on the valve element. Please have the moderator confirm this and get back to me