Instrumentation P&ID Legend
• A
• AH - Alarm High
• AI - Alarm Indicator
• AL - Alarm Low
• AO - Analog Output
• AAH - Analyzer Alarm High
• AAL - Analyzer Alarm Low
• AY - Analyzer Computer
• AC - Analyzer Controller
• AE - Analyzer Element
• AI - Analyzer Indicator
• AIC - Analyzer Indicator Controller
• AIT - Analyzer Indicator Transmitter
• AW - Analyzer Probe
• AR - Analyzer Recorder
• ARC - Analyzer Recorder Controller
• ART - Analyzer Recorder Transmitter
• ASH - Analyzer Switch High
• ASHL - Analyzer Switch High Low
• ASL - Analyzer Switch Low
• AP - Analyzer Test Point
• AT - Analyzer Transmitter
• ATM - Atmosphere
• AOJ - Auto-Off-Jog Selector Switch
• AWT - Automatic Well Test
• B
• BPV - Back Pressure Valve
• BDV - Blow Down Valve
• B - Burner
• BY - Burner Computer
• BC - Burner Controller
• BE - Burner Element
• BG - Burner Glass
• BI - Burner Indicator
• BIC - Burner Indicator Controller
• BIT - Burner Indicator Transmitter
• BW - Burner Probe
• BR - Burner Recorder
• BRC - Burner Recorder Controller
• BRT - Burner Recorder Transmitter
• BSH - Burner Switch High
• BSHL - Burner Switch High Low
• BSL - Burner Switch Low
• BT - Burner Transmitter
• C
• CS - Car Seal
• CSC - Car Seal Closed
• CSO - Car Seal Open
• CAH - Conductivity Alarm High
• CAL - Conductivity Alarm Low
• CE - Conductivity Element
• CIT - Conductivity Indicating Transmitter
• CSH - Conductivity Shutdown High
• CSL - Conductivity Shutdown Low
• CS - Conductivity Switch
• CC - Corrosion Coupon
• CP - Cut Probe
• DE - Density Element
• DR - Density Recorder
• DT - Density Transmitter
• DPSH - Differential Pressure Shutdown High
• DPSL - Differential Pressure Shutdown Low
• DTT - Differential Temperature Transmitter
• DI - Discrete Input (Digital Input)
• DO - Discrete Output (Digital Output)
• E
• ESD - Emergency Shutdown
• EY - Voltage Computer
• EC - Voltage Controller
• EE - Voltage Element
• EI - Voltage Indicator
• EIC - Voltage Indicator Controller
• EIT - Voltage Indicator Transmitter
• ER - Voltage Recorder
• ERC - Voltage Recorder Controller
• ERT - Voltage Recorder Transmitter
• ESH - Voltage Switch High
• ESHL - Voltage Switch High Low
• ESL - Voltage Switch Low
• ET - Voltage Transmitter
• F
• FC - Fail Closed
• FO - Fail Open
• FP - Fail Position
• FA - Fire Alarm
• FA - Flame Arrestor
• F - Flow
• FY - Flow Computer
• FCV - Flow Control Valve
• FC - Flow Controller
• FE - Flow Element
• FG - Flow Glass
• FI - Flow Indicator
• FIC - Flow Indicator Controller
• FIT - Flow Indicator Transmitter
• FM - Flow Meter
• FO - Flow Orifice
• FQY - Flow Quality Computer
• FQE - Flow Quality Element
• FQI - Flow Quality Indicator
• FQIC - Flow Quality Indicator Controller
• FQIT - Flow Quality Indicator Transmitter
• FQR - Flow Quality Recorder
• FQRC - Flow Quality Recorder Controller
• FQSH - Flow Quality Switch High
• FQSL - Flow Quality Switch Low
• FQT - Flow Quality Transmitter
• FFC - Flow Ratio Controller
• FFI - Flow Ratio Indicator
• FFIC - Flow Ratio Indicator Controller
• FFR - Flow Ratio Recorder
• FFRC - Flow Ratio Recorder Controller
• FFSH - Flow Ratio Switch High
• FFSL - Flow Ratio Switch Low
• FR - Flow Recorder
• FRC - Flow Recorder Controller
• FRT - Flow Recorder Transmitter
• FSV - Flow Safety Valve
• FS - Flow Switch
• FP - Flow Test Point
• FT - Flow Transmitter
• G
• GDE - Gas Detector Element
• H
• HC - Hand Controller
• HIC - Hand Indicator Controller
• HS - Hand Switch
• HOA - Hand-Off-Automatic Selector Switch
• I
• IY - Current Computer
• IE - Current Element
• II - Current Indicator
• IIC - Current Indicator Controller
• IIT - Current Indicator Transmitter
• IR - Current Recorder
• IRC - Current Recorder Controller
• IRT - Current Recorder Transmitter
• ISH - Current Switch High
• ISHL - Current Switch High Low
• ISL - Current Switch Low
• IT - Current Transmitter
• IA - Instrument Air
• J
• JY - Power Computer
• JE - Power Element
• JI - Power Indicator
• JIC - Power Indicator Controller
• JIT - Power Indicator Transmitter
• JR - Power Recorder
• JRC - Power Recorder Controller
• JRT - Power Recorder Transmitter
• JSH - Power Switch High
• JSHL - Power Switch High Low
• JSL - Power Switch Low
• JT - Power Transmitter
• K
• KY - Time Computer
• KCV - Time Control Valve
• KC - Time Controller
• KE - Time Element
• KI - Time Indicator
• KIC - Time Indicator Controller
• KIT - Time Indicator Transmitter
• KR - Time Recorder
• KRC - Time Recorder Controller
• KRT - Time Recorder Transmitter
• KSH - Time Switch High
• KSHL - Time Switch High Low
• KSL - Time Switch Low
• KT - Time Transmitter
• L
• LACT - Lease Automatic Custody Transfer
• L - Level
• LAD - Level Alarm Device
• LAHI - Level Alarm High Interface
• LY - Level Computer
• LCV - Level Control Valve
• LCVI - Level Control Valve Interface
• LC - Level Controller
• LCI - Level Controller Interface
• LD - Level Differential
• LE - Level Element
• LEI - Level Element Interface
• LG - Level Glass
• LI - Level Indicator
• LIC - Level Indicator Controller
• LICI - Level Indicator Controller Interface
• LIT - Level Indicator Transmitter
• LW - Level Probe
• LR - Level Recorder
• LRC - Level Recorder Controller
• LRT - Level Recorder Transmitter
• LSHI - Level Shutdown High Indicator
• LSL - Level Shutdown Low
• LSLI - Level Shutdown Low Indicator
• LS - Level Switch
• LSHH - Level Switch High High
• LSL - Level Switch Low
• LSLL - Level Switch Low Low
• LT - Level Transmitter
• LTI - Level Transmitter Interface
• LL - Liquid Level
• LLC - Liquid Level Controller
• LLG - Liquid Level Gauge
• LC - Lock Closed
• LO - Lock Open
• N
• NOC - Net Oil Computer
• NC - Normally Closed
• NO - Normally Open
• O
• OWD - Oil Water Detector
• OM - Orifice Meter
• P
• PAD - Pressure Alarm Device
• PY - Pressure Computer
• PCV - Pressure Control Valve
• PC - Pressure Controller
• PDAH - Pressure Differential Alarm High
• PDY - Pressure Differential Computer
• PDCV - Pressure Differential Control Valve
• PDC - Pressure Differential Controller
• PDI - Pressure Differential Indicator
• PDIC - Pressure Differential Indicator Controller
• PDIT - Pressure Differential Indicator Transmitter
• PDR - Pressure Differential Recorder
• PDRC - Pressure Differential Recorder Controller
• PDRT - Pressure Differential Recorder Transmitter
• PDS - Pressure Differential Switch
• PDSH - Pressure Differential Switch High
• PDSL - Pressure Differential Switch Low
• PDT - Pressure Differential Transmitter
• PE - Pressure Element
• PIT - Pressure Indicating Transmitter
• PI - Pressure Indicator
• PIC - Pressure Indicator Controller
• PR - Pressure Recorder
• PRC - Pressure Recorder Controller
• PRT - Pressure Recorder Transmitter
• PSE - Pressure Safety Element
• PSV - Pressure Safety Valve
• PSH - Pressure Shutdown High
• PSL - Pressure Shutdown Low
• PS - Pressure Switch
• PP - Pressure Test Point
• PT - Pressure Transmitter
• PV - Pressure Valve
• PLC - Programmable Logic Controller
• Q
• QY - Quality Computer
• QE - Quality Element
• QI - Quality Indicator
• QIC - Quality Indicator Controller
• QIT - Quality Indicator Transmitter
• QR - Quality Recorder
• QRC - Quality Recorder Controller
• QRT - Quality Recorder Transmitter
• QSH - Quality Switch High
• QSHL - Quality Switch High Low
• QSL - Quality Switch Low
• QT - Quality Transmitter
• R
• RY - Radiation Computer
• RC - Radiation Controller
• RE - Radiation Element
• RI - Radiation Indicator
• RIC - Radiation Indicator Controller
• RIT - Radiation Indicator Transmitter
• RW - Radiation Probe
• RR - Radiation Recorder
• RRC - Radiation Recorder Controller
• RRT - Radiation Recorder Transmitter
• RSH - Radiation Switch High
• RSHL - Radiation Switch High Low
• RSL - Radiation Switch Low
• RT - Radiation Transmitter
• R - Recorder
• RTD - Resistance Temperature Detector
• RO - Restriction Orifice
• S
• SRV - Safety Relief Valve
• SP - Set Point
• SD - Shutdown
• SDV - Shutdown Valve
• SP - Spare
• SAH - Speed Alarm High
• SY - Speed Computer
• SCV - Speed Control Valve
• SC - Speed Controller
• SE - Speed Frequency Element
• SI - Speed Indicator
• SIC - Speed Indicator Controller
• SIT - Speed Indicator Transmitter
• SR - Speed Recorder
• SRC - Speed Recorder Controller
• SRT - Speed Recorder Transmitter
• SSH - Speed Switch High
• SSHL - Speed Switch High Low
• SSL - Speed Switch Low
• ST - Speed Transmitter
• SLO - Station Lock Out
• SSV - Surface Safety Valve
• S - Switch
• T
• TY - Temperature Computer
• TCV - Temperature Control Valve
• TC - Temperature Controller
• TDI - Temperature Differential Indicator
• TDR - Temperature Differential Recorder
• TD - Temperature Differential
• TDY - Temperature Differential Computer
• TDCV - Temperature Differential Control Valve
• TDC - Temperature Differential Controller
• TDIC - Temperature Differential Indicator Controller
• TDIT - Temperature Differential Indicator Transmitter
• TDRC - Temperature Differential Recorder Controller
• TDRT - Temperature Differential Recorder Transmitter
• TDT - Temperature Differential Transmitter
• TE - Temperature Element
• TI - Temperature Indicator
• TIC - Temperature Indicator Controller
• TIS - Temperature Indicator Switch
• TISHL - Temperature Indicator Switch High Low
• TIT - Temperature Indicator Transmitter
• TW - Temperature Probe
• TR - Temperature Recorder
• TRC - Temperature Recorder Controller
• TRS - Temperature Recorder Switch
• TRT - Temperature Recorder Transmitter
• TSE - Temperature Safety Element
• TS - Temperature Switch
• TP - Temperature Test Point
• TT - Temperature Transmitter
• TW - Thermo well
• T - Transmitter
• U
• UY - Multivariable Computer
• UI - Multivariable Indicator
• UR - Multivariable Recorder
• ULO - Unit Lock Out
• USD - Unit Shut Down
• V
• VFD - Variable Frequency Drive
• V - Vent
• VTA - Vent to Air
• VAHH - Vibration Alarm High High
• VY - Vibration Computer
• VE - Vibration Element
• VI - Vibration Indicator
• VIT - Vibration Indicator Transmitter
• VR - Vibration Recorder
• VRT - Vibration Recording Transmitter
• VS - Vibration Switch
• VT - Vibration Transmitter
• W
• WY - Weight Computer
• WCV - Weight Control Valve
• WC - Weight Controller
• WDC - Weight Differential Computer
• WDCV - Weight Differential Control Valve
• WDC - Weight Differential Controller
• WDI - Weight Differential Indicator
• WDIC - Weight Differential Indicator Controller
• WDIT - Weight Differential Indicator Transmitter
• WDR - Weight Differential Recorder
• WDRC - Weight Differential Recorder Controller
• WDRT - Weight Differential Recorder Transmitter
• WDSH - Weight Differential Switch High
• WDSL - Weight Differential Switch Low
• WDT - Weight Differential Transmitter
• WE - Weight Element
• WI - Weight Indicator
• WIC - Weight Indicator Controller
• WIT - Weight Indicator Transmitter
• WR - Weight Recorder
• WEC - Weight Recorder Controller
• WRT - Weight Recorder Transmitter
• WSH - Weight Switch High
• WSHL - Weight Switch High Low
• Y
• YY - Event Computer
• YC - Event Controller
• YE - Event Element
• YI - Event Indicator
• YIC - Event Indicator Controller
• YR - Event Recorder
• YSH - Event Switch High
• YSL - Event Switch Low
• YT - Event Transmitter
• Z
• ZDY - Gauge Deviation Computer
• ZDCV - Gauge Deviation Control Valve
• ZDC - Gauge Deviation Controller
• ZDE - Gauge Deviation Element
• ZDI - Gauge Deviation Indicator
• ZDIC - Gauge Deviation Indicator Controller
• ZDIT - Gauge Deviation Indicator Transmitter
• ZDR - Gauge Deviation Recorder
• ZDRC - Gauge Deviation Recorder Controller
• ZDRT - Gauge Deviation Recorder Transmitter
• ZDSH - Gauge Deviation Switch High
• ZDSL - Gauge Deviation Switch Low
• ZDT - Gauge Deviation Transmitter
• ZY - Position Computer
• ZCV - Position Control Valve
• ZC - Position Controller
• ZE - Position Element
• ZI - Position Indicator
• ZIC - Position Indicator Controller
• ZIT - Position Indicator Transmitter
• ZR - Position Recorder
• ZRC - Position Recorder Controller
• ZRT - Position Recorder Transmitter
• ZS - Position Switch
• ZSC - Position Switch Closed
• ZSO - Position Switch Open
• ZSHL - Position Switch High Low
• ZT - Position Transmitter