*Q

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

Q: Quantity / Flow / Quick (context dependent)
QA: Quality Alarm / Quantity Alarm
QAC: Quality Alarm Controller / Quantity Alarm Controller
QAM: Quality Alarm Module
QB: Quick Break / Quantity Bus
QBC: Quick Break Controller / Quantity Bus Controller
QC: Quality Controller / Quick Controller
QCA: Quality Control Assembly
QCC: Quality Control Cabinet / Quick Control Cabinet
QCD: Quality Control Device
QCM: Quality Control Module
QCP: Quality Control Panel
QCS: Quality Control System
QD: Quantity Detector / Quick Detector
QDC: Quantity Detector Controller
QDD: Quantity Detection Device
QDS: Quantity Detection System
QE: Quantity Element / Quality Element
QF: Quantity Filter / Quick Filter
QFC: Quantity Flow Controller
QFD: Quantity Flow Device
QFM: Quantity Flow Meter / Quantity Flow Module
QG: Quantity Gauge / Quality Gauge
QH: Quantity High
QI: Quantity Indicator / Quality Indicator
QIC: Quantity Indicating Controller / Quality Indicating Controller
QIM: Quantity Interface Module / Quality Interface Module
QL: Quantity Low / Quality Low
QLA: Quantity Low Alarm / Quality Low Alarm
QLC: Quantity Low Controller / Quality Low Controller
QLI: Quantity Low Indicator / Quality Low Indicator
QLT: Quantity Low Transmitter / Quality Low Transmitter
QM: Quantity Meter / Quality Meter / Quantity Module
QMC: Quantity Module Controller
QN: Quantity Node / Quick Node
QO: Quantity Output / Quick Output
QOC: Quantity Output Controller
QOM: Quantity Output Module
QP: Quantity Point / Quick Point
QPC: Quantity Point Controller
QPD: Quantity Pressure Device
QPI: Quantity Pressure Indicator
QPT: Quantity Pressure Transmitter
QR: Quantity Recorder / Quick Relay
QRC: Quantity Recorder Controller / Quick Relay Controller
QRD: Quantity Relay Device
QS: Quantity Switch / Quick Switch
QSC: Quantity Switch Controller
QSD: Quantity Shutdown Device
QSI: Quantity Status Indicator
QSM: Quantity Signal Module / Quality Signal Module
QT: Quantity Transmitter / Quick Transmitter
QTC: Quantity Temperature Controller
QTD: Quantity Trip Device
QTI: Quantity Temperature Indicator
QTT: Quantity Temperature Transmitter
QV: Quantity Valve / Quick Valve
QVC: Quantity Valve Controller
QVM: Quantity Valve Module