*L

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

L: Level / Limit / Loop (context dependent)
LA: Level Alarm / Local Alarm
LAC: Level Alarm Controller / Local Alarm Controller
LAM: Level Alarm Module
LB: Level Block / Load Bus
LBC: Level Block Controller
LC: Level Controller / Loop Controller
LCA: Level Control Assembly
LCC: Level Control Cabinet
LCD: Level Control Device / Liquid Crystal Display
LCM: Level Control Module
LCP: Level Control Panel
LCS: Level Control System
LD: Level Detector / Load Detector
LDC: Level Detector Controller
LDD: Level Detection Device
LDS: Level Detection System
LE: Level Element / Line Element
LF: Level Filter / Low Frequency
LG: Level Gauge
LGC: Level Gauge Controller
LGL: Level Gauge Low
LGH: Level Gauge High
LH: Level High
LHA: Level High Alarm
LHC: Level High Controller
LHD: Level High Device
LHI: Level High Indicator
LI: Level Indicator / Local Indicator
LIC: Level Indicating Controller
LIM: Level Interface Module / Limit Module
LL: Level Low / Low Level
LLA: Low Level Alarm
LLC: Low Level Controller
LLD: Low Level Device
LLI: Low Level Indicator
LLS: Low Level Switch
LLT: Low Level Transmitter
LM: Level Meter / Loop Module
LMC: Loop / Level Module Controller
LP: Low Pressure / Loop Point
LPC: Loop / Low Pressure Controller
LPI: Loop / Low Pressure Indicator
LPM: Loop / Level Point Module / Liters per Minute
LPT: Low Pressure Transmitter
LR: Level Recorder / Loop Recorder
LRC: Level Recorder Controller
LS: Level Switch / Limit Switch
LSC: Level Switch Controller
LSD: Level Shutdown Device
LSS: Level Safety Switch
LST: Level Switch Transmitter
LT: Level Transmitter / Loop Transmitter
LTC: Level Transmitter Controller
LTD: Level Trip Device
LTI: Level Transmitter Indicator
LTT: Level Transmitter Transducer
LV: Level Valve / Loop Valve
LVC: Level Valve Controller
LVM: Level Valve Module
LW: Level Warning