TO FL A ME P&ID Reference Guide Based on information from ANSI/ISA-5.1-2009 Instrumentation Symbols and Identification R PI 02 Watch the companion PIC Rev. 01/2021 ESD 01 TC 03 TI 02 TI 01 PILOT FUE L G A S P& ID SA MPL E PCV 02 TO FL AME PCV TI 01 TI 03 C O R RO S IO N COUPON 8 8 ,9 m m O. D. G A S F RO M W E L L H E A D C I RC U L AT I N G OI L H E AT E R ALCOHOL S T O R AG E C O R RO S IO N INHIBITOR TA N K ESD 02 DI A P H R AG M PUMP ALCOHOL PUMP OI L R E S E RVOI R PI 02 P -1 P -2 WELL HEAD ESD 01 TC 01 FR TC 02 P IC TC 03 TI 02 TI 01 CHOKE VA LV E PI 01 PILOT PCV 03 FUEL GAS PCV 02 275 8 k Pa F U E L G A S F RO M P L A N T 8 8 ,9 m m O. D. S O U R G A S F RO M P L A N T 1 PCV TI 01 P F D SA MPL E C O O L I N G T OW E R VAC U U M P U M P P RO D U C T TA N K 1 D RU M F U R N AC E F E E D TA N K COLUMN R E AC T O R S B O T T O M S TA N K B OI L E R 2 P RO D U C T TA N K 2 TAG NUMBERS – L E T T ER SY MBOL S F OR DATA PROCE SSING F UNC T IONS Symbol 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 D User's Choice E Voltage F Flow Rate G User's Choice H Hand I Current (Electrical) J Power Scan K Time, Time Schedule Time Rate of Change L Level M User's Choice N User's Choice User's Choice O User's Choice Orifice, Restriction P Pressure, Vacuum Point (Test) Connection Q Quantity R Radiation S Speed, Frequency T Temperature U Multivariable V Vibration, Mechanical Analysis W Weight, Force X Unclassified X Axis Y Event, State or Presence Y Axis Relay, Compute, Convert Z Position, Dimension Z Axis Driver, Actuator, Unclassified Final Control Element Control Differential Sensor (Primary Element) Ratio (Fraction) Glass, Viewing Device High Indicate Control Station Light Low Momentary Middle, Intermediate User's Choice User's Choice Integrate, Totalize Record Safety Switch Transmit Multifunction Multifunction Multifunction Valve, Damper, Louver Well Unclassified Unclassified Unclassified A “ U s e r’s c h oi c e” let te r is u s e d fo r u nliste d m e a nin g s u s e d re p etitively in a p ro j e c t a n d will b e ex p lain e d o n t h e d ia g r a m o r s u p p o r tin g d o c u m e nt. 3 TAG NUMBERS – OIL & G A S INS T RUMEN T A BBRE V I AT IONS (Adapted From ISA Standard S5.1) A AC AAH AAHL AAL AS ASDH ASDL ASH ASHL ASL AT BC BAH BAHL BAL BDV BPR BS BSH BSHL BSL BS&W CCP CDS CFA COR CSC CSO CV E/I ES ESD ESDV FAL FAH FAHH FAHL FALL FC FC FCV FE FFA FFSD FG FI FIC FIT 4 Analog Signal Analysis Controller Analysis Alarm [High] Analysis Alarm [High/Low] Analysis Alarm [Low] Air Supply Analysis Shutdown [High] Analysis Shutdown [Low] Analysis Switch [High] Analysis Switch [High/Low] Analysis Switch [Low] Analysis Transmitter Burner Controller Burner Alarm [High] Burner Alarm [High/Low] Burner Alarm [Low] Blowdown Valve Back Pressure Regulator Burner Switch Burner Switch [High] Burner Switch [High/Low] Burner Switch [Low] Basic Sediment and Water Central Control Panel Compressor Shutdown Common Fault Alarm Corrosimeter Car Seal Close Car Seal Open Control Valve EMF to Current Converter Electrical Switch Emergency Shutdown Station Emergency Shutdown Valve Flow Alarm Low Flow Alarm High Flow Alarm High For Level Above FAH Flow Alarm [High/Low] Flow Alarm Low For Level Below FAL Flow Controller Fail Close Flow Control Valve Flow Element Flame Failure Alarm Flame Failure Shutdown Flow Gage/Flow Sight Glass Flow Indicator Flow Indicator Controller Flow Indicator Transmitter FO FQ FQI FR FRC FRT FS FSDH FSDL FSH FSL FT FY GS H HMV HOA HS I I/F I/I I/P I/PA KI LA LAH LAHH LAHL LAL LALL LC LCV LG LI LIC LIT LLH LLL LLN LQ LR LS LSDH LSDL LSH LSHL LSL LSHH Fial Open Flow Indicator Totaliser Flow Indicator with Total Counter Flow Recorder Flow Recorder Controller Flow Recorder Transmitter Flow Switch Flow Shutdown [High] Flow Shutdown [Low] Flow Switch [High] Flow Switch [Low] Flow Transmitter Computer, Relay, Amplifier or I/P Converter in Flow Loop Instrument Gas Supply Hydraulic Hydraulic Motor Operated Valve Hand/Off/Auto Switch Hand Switch Current Signal Interface Current Indicator Current to Pneumatic Current to Pneumatic Alarm Clock/Timer Level Alarm Level Alarm [High] Level Alarm High for Level Above LAH Level Alarm [High/Low] Level Alarm [Low] Level Alarm Low for Level Above LAL Level Controller Level Control Valve Level Gauge Level Indicator Level Indicator Controller Level Indicator Transmitter Liquid Level [High] Liquid Level [Low] Liquid Level [Normal] Lock Closed When by a manual Valve Level Recorder Level Switch Level Shutdown [High] Level Shutdown [Low] Level Switch [High] Level Switch [High/Low] Level Switch [Low] Level Switch High for Level Above LSH LSLL LT LY LO MCC MTU NC NO P PAH PAHL PAL PB PC PCV PD PdA PdAH PdAL PdI PdIC PdS PdSH PdSL PG P/I PI PIC PIT PJI PJR POV PR PRC PRT PRV PSDH PSDL PSE PSH PSHH PSHL PSL PSLL PSV PT POS PY Level Switch Low for Level Below LSL Level Transmitter I/P Converter [Level Loop] Lock Open Motor Control Center Master Terminal Unit Normally Closed Normally Open Pneumatic Signal Pressure Alarm [High] Pressure Alarm [High/Low] Pressure Alarm [Low] Pushbutton Pressure Controller Pressure Control Valve Pulsation Dampener Pressure Differential Alarm Pressure Differential Alarm [High] Pressure Differential Alarm [Low] Pressure Differential Indicator Pressure Differential Indicator Controller Pressure Differential Switch Pressure Differential Switch [High] Pressure Differential Switch [Low] Pressure Gage Pneumatic To Current Converter Pressure Indicator Pressure Indicator Controller Pressure Indicator Transmitter Multipoint Pressure Indicator Multipoint Pressure Recorder Pneumatically Operated Valve Pressure Recorder Pressure Recorder Controller Pressure Recorder Transmitter Pressure Regulating Valve Pressure Shutdown [High] Pressure Shutdown [Low] Rupture Disk Pressure Switch [High] Pressure Switch High for Pressure Above PSH Pressure Switch [High/Low] Pressure Switch [Low] Pressure Switch Low for Pressure Below PSL Pressure Safety Valve Pressure Transmitter Positioner Relay, Computer, Amplifier, Converter or I/P Converter etc/ in Pressure Loop RC RTD RTU S SAH SAHL SAL SC SD SI SR SS SSH SSHL SSL TAH TAHL TAL TC TCV TD TE TF TH TI TIC TIT TJI TR TRC TRT TSDH TSDL TSH TSHL TSL TT TW TY US VAH VSDH VSH WS X ZC ZO Ratio Controller Resistance Temperature Detector Remote Terminal Unit Solenoid Speed Alarm [High] Speed Alarm [High/Low] Speed Alarm [Low] Sample Connection Shutdown Panel Speed Indicator Speed Recorder Steam Supply Speed Switch [High] Speed Switch [High/Low] Speed Switch [Low] Temperature Alarm [High] Temperature Alarm [High/Low] Temperature Alarm [Low] Temperature Controller Temperature Control Valve Time Delay Temperature [Measuring] Element/Thermocouple Temperature Gage Thermostat Temperature Indicator Temperature Indicator Controller Temperature Indicator Transmitter Multipoint Temperature Indicator/Thermocouple Temperature Recorder Temperature Recorder Controller Temperature Recorder Transmitter Temperature Shutdown [High] Temperature Shutdown [Low] Temperature Switch [High] Temperature Switch [High/Low] Temperature Switch [Low] Temperature Transmitter Thermowell Computer, Relay, Converter, etc. in Temp. Loop Utility Station Vibration Alarm [High] Vibration Shutdown [High] Vibration Switch [High] Water Supply Multiply Position Switch [Closed] Position Switch [Open] TAG NUMBERS – L OOP NUMBER The number below these letters is the numerator to help identify a specific component on a project within the control loop. When there are multiples of the same device used in a diagram, this number helps viewers to reference that specific instrument. TI 01 TC 01 TC 02 If you were looking at a list of the controls, you could look at the control loop number to find that specific device on the P&ID. Companies have different protocols for where these numbers originate. SECOND TEMP. CONTROLLER IN THE CONTROL LOOP FIRST TEMP. CONTROLLER IN THE CONTROL LOOP TAG NUMBERS – INS T RUMEN T L OC AT ION FIRST TEMP. INDICATOR IN THE CONTROL LOOP • Located in field • Not panel, cabinet, or console mounted • Visible at field location • Normally operator accessible • Located in or on front of central or main panel or console • Visible on front of panel or on video display • Normally operator accessible at panel front or console • Located in rear of central or main panel • Located in cabinet behind panel • Not visible on front of panel or on video display • Not normally operator accessible at panel or console • Located in or on front of secondary or local panel or console • Visible on front of panel or on video display • Normally operator accessible at panel front or console ME A SURED OR INI T I AT ING VA RI A BL E MODIF IER T IC 01 MODIF IER RE ADOUT/PASSIVE FUNCTION, OUTPUT FUNCTION, MODIFIER L OC AT ION INDIC AT OR FIELD MOUNTED, PRIMARY LOCATION, AUXILIARY LOCATION IDEN T IF Y ING NUMBER • Located in rear of secondary or local panel • Located in field cabinet • Not visible on front of panel or on video display • Not normally operator accessible at panel or console These symbols may be supplemented with information on the name of the local control room or the local control panel, just outside the symbols, for example, COMPRESSOR, i.e., the local control room or local control panel for a compressor. 5 NUMERATOR IDENTIFICATION WITHIN THE CONTROL LOOP INS T RUMEN T SY MBOL DISCRETE INSTRUMENTS, SHARED DISPL AY/CONTROL, ETC. SY MBOL S – L INE T Y PE S Piping (Major Projcess) 6 Connection to Process (Minor Process) • Functional diagram continuously variable signal. • Electrical schematic ladder diagram signal and power rails. Undefined Signal • Use for Process Flow Diagrams and diagrams where type of signal is not of concern Pneumatic Signal • Filled thermal element capillary tube. • Filled sensing line between pressure seal and instrument. Electric Signal • Electronic or electrical continuously variable or binary signal. • Functional diagram binary signal. Hydraulic Signal • Hydraulic Signal Capillary Tube • Filled thermal element capillary tube. • Filled sensing line between pressure seal and instrument. Electromagnetic or Sonic Signal (Guided) • Guided electromagnetic signal / sonic signal. • Fiber optic cable. Electromagnetic or Sonic Signal (Not Guided) • Unguided electromagnetic signals, light, radiation, radio, sound, wireless, etc. • Wireless instrumentation signal / communication link. Internal System Link (Software or Data Link) • Communication link and system bus, between devices and functions of a shared display, shared control system. (DCS, PLC, or PC communication link and system bus.) Internal System Link (Software or Data Link) • Communication link or bus connecting two or more independent microprocessor or computer-based systems. (DCS-to-DCS, DCS-to-PLC, PLC-to-PC, DCS-to-Fieldbus, etc.) Mechanical Link • Mechanical Link SY MBOL S – CON T ROL VA LV E S 1 a. b. 2 12 Generic damper Generic louver Generic two-way angle valve Angle globe valve Safety angle valve 13 Parallel blade damper Parallel blade louver Generic three-way valve Three-way globe valve 14 Opposed blade damper Opposed blade louver Generic four-way valve Four-way four-ported plug or ball valve 15 Two-way on-off solenoid valve 5 Butterfly valve 16 Angle on-off solenoid valve 6 Ball valve 17 Three-way on-off solenoid valve Arrow indicates de-energized flow path 7 Plug valve 18 Four-way plug or ball on-off solenoid valve Arrows indicates de-energized flow paths 3 Arrow indicates failure or unactuated flow path 4 Arrows indicates failure or unactuated flow paths Eccentric rotary disc valve 19 Four-way five-ported on-off solenoid valve Arrows indicates de-energized flow paths Diaphragm valve 20 Permanent magnet variable speed coupling 10 Pinch valve 21 11 Bellows sealed valve 8 9 7 Generic two-way valve Straight globe valve Gate valve a. b. Electric motor Represents a motor that manipulates or controls a process variable. Symbols 1-14, when combined with actuator symbols 1-16, represent process control valves. Symbol 2, when combined with actuator symbols 20 and 21, represent pressure safety valves. Symbols 1 and 9, users design standards will document which symbols have been selected. Symbols 15-19, when combined with actuator symbols 13-15, represent on-off solenoid valves. Symbol 21, when combined with actuator symbols 1-16, represents a variable speed control unit. SY MBOL S – AC T UAT ORS 1 Generic actuator Spring-diaphragm actuator 12 Actuator with top-mounted handwheel 2 Spring-diaphragm actuator with positioner 13 Manual actuator Hand actuator 3 Pressure-balanced diaphragm actuator 14 4 Linear piston actuator Single acting spring opposed Double acting. 15 5 Linear piston actuator with positioner 16 6 Rotary piston actuator May be single acting spring opposed or double acting 17 7 Rotary piston actuator with positioner 18 8 Bellows spring opposed actuator 19 Rotary motor operated actuator Electric, pneumatic, or hydraulic Linear or rotary action 20 Modulating solenoid actuator Solenoid actuator for process on-off valve 21 9 10 11 8 M S Actuator with side-mounted handwheel E H Electrohydraulic linear or rotary actuator Actuator with manual actuated partial stroke test device S Automatic reset on-off solenoid actuator Non-latching on-off solenoid actuator S S R Manual or remote reset on-off solenoid actuator Latching on-off solenoid actuator R Manual and remote reset on-off solenoid actuator Latching on-off solenoid actuator S R Actuator with remote actuated partial stroke test device Spring or weight actuated relief or safety valve actuator P Pilot actuated relief or safety valve actuator Pilot pressure sensing line deleted if sensing is internal Symbols 1-16, when combined with element symbols 1-14, represent process control valves and with element symbol 21 represents a variable speed control unit. Symbols 17-19, when combined with element symbols 15-19, represent on-off solenoid valves. Symbols 20-21, when combined with element symbol 2, represent pressure safety valves. SY MBOL S – COMMON VA LV E SY MBOL S A ND COMBIN AT IONS + Combining control valve symbols with actuators symbols can yield a variety of results. Below are some final control elements with actuators and a variety of other common instrument symbols. GATE VALVES Gate Hand Operated (Manual) Pneumatic (Diaphragm) Globe Valve = Hand Actuator Hand-Operated Globe Valve FAIL-SAFE POSITION M H Motor Hydraulic Pneumatic (Rotary Piston) Balance Diaphragm Pressure Regulator Back Pressure Regulator Fail Closed GLOBE VALVES OTHER VALVES H M S Fail Open Globe Hand Operated Pneumatic Motor ANGLE VALVES Hydraulic Bleeder Integrated Block Solenoid Closed Knife Slide M END CONNECTION Flanged Angle Hand Operated BALL VALVES Ball Pneumatic PLUG VALVES H Plug Hydraulic DIAPHRAGM VALVES Motor M Angle Blowdown M Motor SAFETY RELIEF Piston-Operated Float-Operated BUTTERFLY VALVES Butterfly Rotary Pinch Needle CHECK VALVES Pneumatic QUARTER TURN Check Valve Treaded Stop Check Welded EQUIPMENT Socket Weld Diaphragm 9 Motor PSV PRV Quarter Turn Valve Double Acting Quarter Turn Valve Spring Acting Rotameter Gauge Orifice SY MBOL S – EQ UIPMEN T C EN T R I F UG A L P U MP S P OSI T I V E DISP L AC E M EN T P U MP S C OOL ING T O W E R S Positive Displacement Centrifugal Pumps Positive Displacement Induced Draft Crossflow Gear Pump Forced Draft Counterflow Vertical Can Pump Natural Draft Counterflow Progressive Cavity Vertical Screw Pump Horizontal Screw Pump Vertical Vacuum Pump Sump Pump Reciprocating Pump S T OR AGE 10 Bin Drum External Floating Roof Tank Internal Floating Roof Tank Sphere Dome Roof Tank Double Wall Tank Onion Tank Open Top Tank Cone Roof Tank Hyperbolic Chimney Tower SY MBOL S – EQ UIPMEN T C EN T R I F UG A L C OMP R E S SOR S T P D C OMP R E S SOR S R E AC T OR SY MBOL S Centrifugal Compressor Reciprocating Compressor Centrifugal Compressor (Turbine Driven) Liquid Ring Vacuum Centrifugal Compressor Reciprocating Compressor Axial Compressor Rotary Compressor Centrifugal Blower Rotory Compressor & Silencers MO T OR S Hydrocracking Fluid Coking Reformer Hydrodesulfurization Tubular Reactor Fluidized Reactor Fluid Catalytic Cracking Alkylation Mixing Reactor Rotary Screw Compressor Motor Positive Displacement Blower Diesel Motor S T E A M T U R BINE Agitator or Mixer F U R N AC E A ND BOI L E R Turbine Driver Furnace Doubleflow Turbine 11 Boiler SY MBOL S – EQ UIPMEN T HE AT E XCH A NGE R S Plate and Frame Heat Exchanger Spiral Heat Exchanger Heater Air Cooled Exchanger (Louvers Optional) U-Tube Heat Exchanger Condenser Double-Pipe Heat Exchanger Single Pass Heat Exchanger C C Shell and Tube Heat Exchanger Hairpin Exchanger Reboiler DIS T I L L AT ION SY MBOL S Single Pass Demister Spray Nozzle Chimney Two Pass Packed Section Draw Off Generic Tray Plate Tower Bubble-cap, Sieve, Valve 12 Packed Tower Saddle, Ring, Sulzer, Rosette Manway Vortex Breaker