Pipe and Instrumentation Diagram



 

 
First Letter
Succeeding Letters
  Measured or Initiating Variable Modifier Readout or Passive Function Output Function Modifier
A
 Analysis   Alarm    
B
 Burner, Combustion   User’s Choice User’s Choice User’s Choice
C
 User’s Choice      Control  
D
 User’s Choice Differential      
E
 Voltage   Sensory (Primary)    
F
 Flow Rate Ratio (fraction)      
G
 User’s Choice   Glass, Viewing    
H
 Hand       High
I
 Current   Indicate    
J
 Power Scan      
K
 Time, 
Time Schedule		 Time Rate of Change   Control Station  
L
 Level   Light   Low
M
 User’s Choice Momentary     Middle
N
 User’s Choice   User’s Choice User’s Choice User’s Choice
O
 User’s Choice   Orifice    
P
 Pressure, Vacuum   Point, Test    
Q
 Quantity Integrate, Totalize      
R
 Radiation   Record    
S
 Speed, Frequency Safety   Switch  
T
 Temperature     Transmit  
U
 Multivariable   Multifunction Multifunction Multifunction
V
 Vibration        
W
 Weight, Force   Well    
X
 Unclassified x-axis Unclassified Unclassified Unclassified
Y
 Event, State y-axis   Relay, Compute  
Z
 Position, Dimension z-axis   Driver, Actuator  

 
 




(Adapted from Bruce G. Lovelace, "Piping and Instrument Diagrams", handout given at seminar held at Michigan Technological University, Dept. of Chemical Engineering, November 5, 1992)

This page is maintained by Tomas B. Co (tbco@mtu.edu). Last revised 12/2/1999.

Tomas B. Co
Associate Professor
Department of Chemical Engineering
Michigan Technological University
1400 Townsend Avenue
Houghton, MI 49931-1295

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