Service Classification

Written by Jerry Ratzlaff on . Posted in Designer

A service classification or service class is a one to three letter designation that shows what service the line is in.  It is typically shown on a Piping and Instrumentation Diagram as part of the line numbering system.  

Most companies have their own standard or specification of calling out the pressure classification.  However, as an example, some different service classifications are shown below.  This is by no means an all inclusive list.  

Before creating line numbers, check with your own companies specification.  

IDLine Service
AI Instrument Air
BR Brine
CA Caustic
CD Condensate
CI Chemical Injection
CO2 Carbon Dioxide
DE Filter Aid Solution
DR Drain
EM Emulsion
EW Eye Wash Water
FL Flare Line
FG Fuel Gas
GH Gas Hydrocarbon
GL Glycol
IAS Instrument Air Supply
LH Liquid Hydrocarbon
KW Killwater
PW Produced Water
SA Salt
SN Sodium Nitrate
ST Steam
SW Soft Water
UA Utility Air
UW Utility Water
WR Water