*R

Here’s a list of Instrumentation abbreviations starting with the letter “R”, commonly used in P&IDs, datasheets, control systems, and field instrumentation.

R: Relay / Recorder / Remote (context dependent)
RA: Relay Alarm / Remote Alarm
RAC: Relay Alarm Controller / Remote Alarm Controller
RAM: Relay Alarm Module
RB: Relay Bus / Remote Bus
RBC: Relay Bus Controller / Remote Bus Controller
RC: Relay Controller / Remote Controller
RCA: Relay Control Assembly / Remote Control Assembly
RCC: Relay Control Cabinet / Remote Control Cabinet
RCD: Relay Control Device / Remote Control Device
RCM: Relay Control Module / Remote Control Module
RCP: Relay Control Panel / Remote Control Panel
RCS: Relay Control System / Remote Control System
RD: Relay Device / Recorder Device
RDC: Relay Device Controller / Recorder Device Controller
RDD: Relay Detection Device
RE: Relay Element / Remote Element
RF: Radio Frequency / Relay Feedback
RFC: Radio Frequency Controller / Relay Feedback Controller
RFD: Relay Feedback Device
RG: Relay Gauge / Remote Gauge
RH: Relay High / Remote High
RI: Relay Indicator / Remote Indicator
RIC: Relay Indicating Controller / Remote Indicating Controller
RIM: Relay Interface Module / Remote Interface Module
RL: Relay Low / Remote Low
RLA: Relay Low Alarm / Remote Low Alarm
RLC: Relay Low Controller / Remote Low Controller
RLI: Relay Low Indicator / Remote Low Indicator
RLT: Relay Low Transmitter / Remote Low Transmitter
RM: Relay Module / Remote Module
RMC: Relay Module Controller / Remote Module Controller
RN: Relay Node / Remote Node
RO: Relay Output / Remote Output
ROC: Relay Output Controller / Remote Output Controller
ROM: Relay Output Module / Remote Output Module
RP: Relay Panel / Remote Point / Reference Point
RPC: Relay Panel Controller / Remote Point Controller
RPD: Relay Pressure Device / Remote Pressure Device
RPI: Relay Pressure Indicator / Remote Pressure Indicator
RPT: Relay Pressure Transmitter / Remote Pressure Transmitter
RR: Relay Recorder / Remote Recorder
RRC: Relay Recorder Controller / Remote Recorder Controller
RRD: Relay Relay Device / Remote Relay Device
RS: Relay Switch / Remote Switch
RSC: Relay Switch Controller / Remote Switch Controller
RSD: Relay Shutdown Device / Remote Shutdown Device
RSI: Relay Status Indicator / Remote Status Indicator
RSM: Relay Signal Module / Remote Signal Module
RT: Relay Transmitter / Remote Transmitter / Resistance Temperature
RTC: Relay Temperature Controller / Remote Temperature Controller
RTD: Resistance Temperature Detector
RTI: Relay Temperature Indicator / Remote Temperature Indicator
RTT: Relay Temperature Transmitter / Remote Temperature Transmitter
RV: Relay Valve / Remote Valve
RVC: Relay Valve Controller / Remote Valve Controller
RVM: Relay Valve Module / Remote Valve Module