Differential pressure flow meter
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There is currently a differential pressure flow meter, with a manual valve in front of it. Process operators manually open and close this valve to control the flow rate; they always set the valve to a very low position, which results in no reading on the flow meter. Need a solution, urgently.
Try compressing the range proportionally； After the reading is available. Calculating the new range based on the data
Use a flow meter with a smaller range.
Based on the circumstances, it is estimated that this is a flow meter used for measurement; the performance of the operating unit is evaluated based on the data collected by this flow meter. As a result, operators are motivated to keep the valves closed tightly so that the flow meter does not record any flow, thereby reducing the costs for the operating unit. If that’s the case, it’s a purely human-related issue, and it’s not easy to resolve. Could we do this: design a minimum flow rate, and if the flow drops to that minimum level, the automatic shut-off valve on the pipeline will close, preventing unauthorized use. This also relates to ensuring the stability of subsequent production, and it needs to be taken into consideration.
Hello. How exactly is it done?
Hello. Your analysis is correct; the operator has now set the valve to a very low position. So it is not displayed.
If that’s the case, there are several methods that can be tried: 1. If the steam consumption of the subsequent process system is not high, the range of the flow meter can be recalculated to lower the threshold for low flow rates. 2. Modify the valve in front of the flow meter to a pneumatic control valve; identify on the DCS system the valve opening degree at which no flow is indicated, and use the DCS system to set this value to close the valve directly. Pneumatic control valves are not equipped with a handwheel mechanism to prevent manual interference. 3. Determine the steam usage based on the requirements of the downstream processes; if continuous and stable steam supply is possible, this stream of steam can be considered as operating in a mode of low-diameter, continuous steam supply. Reducing the valve opening cannot meet the subsequent steam demand. 4. Set an interlock using the zero flow value of the steam flow meter; when the flow meter reads zero, the steam valve is immediately closed via the interlock. Due to a lack of understanding of the actual steam usage, only a few rough suggestions can be offered for reference.
The simplest solution is to lock the manual valve!