Regarding the representation of level gauges on P&IDs
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As shown in the figure, in a magnetic flap level gauge (indicated as LI in the figure), when the liquid level reaches a certain height, it triggers the solenoid valve to activate, causing the pneumatic valve to open and allow drainage. So how can a level gauge with such a control mechanism be represented in a P&ID? The customer believes the drawing in the picture is incorrect; please give some advice, master
The level gauge is set too high~~~ It’s insanely high. It would be sufficient to place it on a part of the tank; with your design, wouldn’t it be necessary to fill the tank to a high level in order to be able to measure the level? Can it only be measured with an empty tank at a low level? Is there also an issue with the drawing scale? The valve proportion is too large; some of them are almost as big as one-third of the tank’s size~~~
I suggest looking at a few sets of finished drawings. I’m not familiar with the regulations, but this is clearly very different from the drawings I’ve seen before. The design of the level gauge exceeds my understanding~~~
Take a look at HG/T 20505-2014 \"Functional Indicators and Graphic Symbols for Process Measurement and Control Instruments\"
Take a look at HG/T 20505-2014 \"Functional Indicators and Graphic Symbols for Process Measurement and Control Instruments\"
The LS for the liquid level is indicated on the level gauge; what’s the reason you’ve drawn it on the valve? A dashed line should be drawn from LS to represent the control line, leading to the solenoid valve
This post was last edited by wzd871224 on 2017-6-14 09:23. Take a look at this.............Thought the reply didn’t succeed; please delete it
Take a look at this; I hope it can help you
When the control is represented by a wire connection, how is it possible that connecting it directly results in a hard link?
Draw the interlock lines, and indicate the high/low alarm markers
Does the magnetic flap gauge have remote data transmission? If remote transmission is available, an alarm value must also be set in the system after the liquid level is detected in order to control the operation of the solenoid valve. If this magnetic flip switch is not used for control, a float switch can be installed directly, with this digital signal being used to control the solenoid valve.