*U

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

U: Utility / Unit / Ultrasonic (context dependent)
UA: Utility Alarm / Ultrasonic Alarm
UAC: Utility Alarm Controller / Ultrasonic Alarm Controller
UAM: Utility Alarm Module / Ultrasonic Alarm Module
UB: Utility Bus / Unit Bus
UBC: Utility Bus Controller / Unit Bus Controller
UC: Utility Controller / Unit Controller / Ultrasonic Controller
UCA: Utility Control Assembly / Unit Control Assembly
UCC: Utility Control Cabinet / Unit Control Cabinet
UCD: Utility Control Device / Unit Control Device
UCM: Utility Control Module / Unit Control Module
UCP: Utility Control Panel / Unit Control Panel
UCS: Utility Control System / Unit Control System
UD: Utility Device / Ultrasonic Device
UDC: Utility Device Controller / Ultrasonic Device Controller
UDD: Utility Detection Device / Ultrasonic Detection Device
UE: Utility Element / Ultrasonic Element
UF: Utility Filter / Ultrasonic Filter
UFC: Utility Flow Controller / Ultrasonic Flow Controller
UFD: Utility Flow Device / Ultrasonic Flow Device
UFM: Utility Flow Meter / Ultrasonic Flow Meter
UG: Utility Gauge / Ultrasonic Gauge
UH: Utility High / Ultrasonic High
UI: Utility Indicator / Ultrasonic Indicator
UIC: Utility Indicating Controller / Ultrasonic Indicating Controller
UIM: Utility Interface Module / Ultrasonic Interface Module
UL: Utility Low / Ultrasonic Low
ULA: Utility Low Alarm / Ultrasonic Low Alarm
ULC: Utility Low Controller / Ultrasonic Low Controller
ULD: Utility Low Device / Ultrasonic Low Device
ULI: Utility Low Indicator / Ultrasonic Low Indicator
ULT: Utility Low Transmitter / Ultrasonic Low Transmitter
UM: Utility Module / Unit Module / Ultrasonic Module
UMC: Utility Module Controller / Unit Module Controller
UN: Utility Node / Unit Node
UO: Utility Output / Unit Output
UOC: Utility Output Controller / Unit Output Controller
UOM: Utility Output Module / Unit Output Module
UP: Utility Point / Unit Point
UPC: Utility Point Controller / Unit Point Controller
UPD: Utility Pressure Device / Unit Pressure Device
UPI: Utility Pressure Indicator / Unit Pressure Indicator
UPT: Utility Pressure Transmitter / Unit Pressure Transmitter
UR: Utility Recorder / Unit Relay
URC: Utility Recorder Controller / Unit Relay Controller
URD: Utility Relay Device / Unit Relay Device
US: Utility Switch / Ultrasonic Switch
USC: Utility Switch Controller / Ultrasonic Switch Controller
USD: Utility Shutdown Device / Unit Shutdown Device
USI: Utility Status Indicator / Ultrasonic Status Indicator
USM: Utility Signal Module / Ultrasonic Signal Module
UT: Utility Transmitter / Unit Transmitter / Ultrasonic Transmitter
UTC: Utility Temperature Controller / Ultrasonic Temperature Controller
UTD: Utility Trip Device / Unit Trip Device
UTI: Utility Temperature Indicator / Ultrasonic Temperature Indicator
UTT: Utility Temperature Transmitter / Ultrasonic Temperature Transmitter
UV: Utility Valve / Unit Valve / Ultrasonic Valve
UVC: Utility Valve Controller / Ultrasonic Valve Controller
UVM: Utility Valve Module / Ultrasonic Valve Module