Instrument Naming
From Piping-Designer
On a Piping and Instrumentation Diagram, instruments are designated by an alphanumeric code or tag:
| Letter | First Letter | Second Letter | Third Letter |
|---|---|---|---|
| A | Analyzer | Alarm | |
| B | Burner or Combustor | ||
| C | Available | ||
| D | Available | ||
| E | Voltage | Element | |
| F | Flow Rate | ||
| G | Available | Glass | |
| H | Hand | High | |
| I | Current (Electrical) | Indicator | |
| J | Power | ||
| K | Time, Schedule | ||
| L | Level | Light | Low |
| M | Available | Middle | |
| N | Available | ||
| O | Available | Orifice | |
| P | Pressure | Connection Point (Test) | |
| Q | Quantity | ||
| R | Radiation | Record | |
| S | Speed | Switch | |
| T | Temperature | Transmitter | |
| U | Multivariable | Multi-function | |
| V | Vibration | Valve | |
| W | Weight | Well | |
| X | Unclassified | Unclassified | |
| Y | Event | ||
| Z | Position | Actuator, Driver |
These letters go together to form unique Instrumentation Identification. The typical Instrumentation Matrix is a good starting place for typical instrumentation found in a plant.
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