Solution to drift phenomenon of prepaid steam flowmeter
Pre-paid steam flowmeters will have different situations when they are used. Flowmeter transmitter drift is a common one, which will affect the normal measurement of the flowmeter. When this phenomenon occurs, we can take the following measures:
1. When the prepaid steam flow meter works normally, the middle valve of the three-valve group is closed, and the two-end valve is open. If you need to drain or condense, close the two-end valve first, then open the middle valve, and then drain the root The valve is opened for draining. If condensation occurs, you want to close the middle valve, and then gradually open the two-end valve, which is the normal working condition of the system.
2. There are two positive and negative signal lines on the differential pressure transmitter. Remove one of them. Adjust the multimeter to the 4-20mA DC range. String the multimeter in. The differential pressure transmitter has a zero adjustment screw, clockwise. When debugging, the current increases, but instead decreases. When the multimeter shows 4mA, clarify the zero point at this moment to adjust.
3. It is necessary to check the prepaid steam flow meter according to the daily inspection requirements for the new replacement ventilation operation for one week.
4. When the measurement medium is steam, online zero adjustment should be performed, because the condensation plate may have a slight height difference during installation, and when the flow velocity of the measurement fluid is small, the height difference will have a greater impact on the flow rate at this time.
5. It is necessary to check the daily protection requirements of the prepaid steam flow meter within one week after the meter is qualified after the periodic verification of the flow meter.
6. The pre-paid steam flow meter filter device with a bleed valve should be bleeded every 6 months. Filter conditions without pressure relief valve should consider open clean barrier filters.
The drift phenomenon of the pre-paid steam flow meter, although it is only a slight change, will have a great impact on the measurement results. Therefore, the flow meter needs to have accurate measurement in the process of use.