P&ID symbols Flashcards
define the term tag numbers
letters and numbers placed within or near the instrument to identify the type and function of the device
The first letter of the tag is used
to designate the measured variable
What the four common measured variables for the first letter
Flow Temperature Pressure Level
Other 6 measured variables for the first letter
Current Hand Position Analysis
with Quantity Vibration
First letter modifiers
differential ratio safety totalizer
The succeeding letter(s) are used to
designate the function of the component or to modify the meaning of the first letter
What the four most succeeding letters
Controller
Recorder
Indicator
Transmitter
What are the other succeeding letters
Switch valve actuator
what are the succeeding modifiers
high and low
No line in a tag means
the instrument is mounted in the field near the process aka in plant
(close to operator)
Solid line in tag means
Mounted in control room and is accessible to the operator
Dotted line in tag
mounted out of sight and is not accessible to operator
Circle tags alone
distinct elememnts
Circle tag in square
Shared Display
Shared Control in DCS
Hexagon tag instead of circle tag
Computer logic function
