Advertisement
P&ID SYMBOLS - HOW TO READ FOR VESSELS, COMPRESSORS AND PUMPS
Advertisement
Vessels
Storage tanks, drums and process vessels are depicted using the following standard symbols.
Pumps, Fans & Compressors
Blowers, fume exhausters, air compressors, pressure fans and the like are shown using variations of the following symbols.
Sensors, Transmitters & Meters
Instrumentation devices — like sensors, transmitters and meters — measure, record and control different parts of the flow process. In a P&ID, these components are shown using various shapes to represent each instrument and explain how they are connected.
Horizontal lines are also used to define where an instrument is located and if it is accessible.
Tag Numbers
Letters and numbers can be included inside the shapes to further dictate information, such as the property being measured and the function associated with that measurement.
There can be up to 5 letters in a tag:
- The first letter is for the measured value (current, power, pressure, etc.)
- The second letter is a modifier (gas, ratio, difference, etc.)
- The third letter defines the readout/passive function (sensor, indicate, light, etc.)
- The fourth letter is the output/active function (control station, switch, etc.)
- The fifth letter is a function modifier (run, stop, etc.)
The letters are followed by a loop number, which indicates the location and function of the instrument. In the example below, FT is a flow transmitter and the 028 sequence number indicates the location of the device. A sequence number is assigned to all devices within the same function.
Post a Comment