Control theory, process concepts, and general industrial-automation terms. This page (4 of 6) covers NFPA 497 (gas/vapor areas) to Safe Fill Level.
Control theory, process concepts, and general industrial-automation terms.
The recommended practice for classifying flammable gas and vapor areas: release sources, area type, and extent.
Read → GlossaryThe NEC as a document: how it is structured, adopted into law, and applied to SCADA panels and field wiring.
Read → GlossaryThe electrical safe-work standard: permits, PPE categories, boundaries and de-energizing.
Read → GlossaryEstimating each producer's liquids from GPM times volume, then scaling to the plant's actual recovered barrels.
Read → GlossaryThe heating value of gas at a flare's flame after assist dilution, kept above a floor and computed live for compliance.
Read → GlossaryMakeup N2 side that adds nitrogen to hold pad pressure as level or temperature falls, split-range with the conservation vent.
Read → GlossaryThe FMEDA categories, no-effect, no-part, annunciation, that are excluded from SFF and PFD math.
Read → GlossaryMaster-polled guarding with a toggle bit versus node-produced heartbeat messages, and why heartbeat is preferred for alarms.
Read → GlossaryA decision guide: when free-space radar's no-touch reliability wins and when a guided probe is needed.
Read → GlossaryThe breathing vent for pumping and thermal flows versus the emergency vent sized for the fire-exposure case.
Read → GlossaryThe upward-facing side of a gateway or SCADA server that exposes field data to enterprise and cloud systems.
Read → GlossaryA closed-loop alert that demands a reply and re-escalates if none comes, so the system knows a human has it.
Read → GlossaryCascading one alarm to the same person across push, SMS, and voice when earlier channels are not confirmed.
Read → GlossaryConfirmation that a notification reached the recipient's device, distinct from merely sent and from acknowledged.
Read → GlossaryScheduled windows that hold low-priority alerts overnight while critical alarms override to reach on-call staff.
Read → GlossaryHow Clean Water Act discharge permits set effluent limits and sampling, and how readings become Discharge Monitoring Reports.
Read → GlossaryThe pressure margin above boiling at a pump inlet, the available-vs-required rule, and how suction trending guards against cavitation.
Read → GlossaryThe cushion between available and required NPSH, why a thin one invites cavitation, and how telemetry alarms it shrinking.
Read → GlossaryThe crossover serial cable that swaps TX and RX so two DTE devices can talk directly.
Read → GlossaryA wobbling-disc PD meter that displaces a fixed volume per cycle; the classic low-cost water meter.
Read → GlossaryThe raw hydrometer reading at sample temperature, corrected to 60F before it lands on a custody ticket.
Read → GlossaryAn iterative API 11.1 loop converts flowing density to base density at 60 degF, feeding CTL and mass-volume conversion.
Read → GlossaryThe profit lost when fuel is blended above the octane minimum, and how closed-loop analysers trim it to a small margin.
Read → GlossaryOGOR-B assigns every barrel and Mcf a disposition code and balances only when gauges and meters reconcile.
Read → GlossaryHow oil to the water leg and water to sales oil signal a treater upset, their causes, and how SCADA monitoring catches them.
Read → GlossaryThe factor that links downhole and surface oil volumes, explaining why a reservoir barrel shrinks to fewer stock-tank barrels.
Read → GlossaryThe subsynchronous journal-bearing instabilities near 0.42 to 0.48X and the resonance lock that turns whirl into whip.
Read → GlossaryThe 360-degree master-station antenna that serves many remotes in a point-to-multipoint network.
Read → GlossaryA silent window where no one is assigned to receive alarms, and how validation catches it before it bites.
Read → GlossaryThe recurring calendar that decides who receives alarm notifications now, and how it feeds escalation.
Read → GlossaryThe cutover when a rotation changes hands and active, unacknowledged alarms transfer to the incoming responder.
Read → GlossaryLightweight checks on the gateway that flag abnormal readings locally, even when the backhaul is down.
Read → GlossaryThe simplest control mode - full open or full closed with a differential gap - on dump valves, heaters, and pumps.
Read → GlossaryEdge-detect logic that pulses for one scan on a transition, for counting once, latching, and snapshots.
Read → GlossaryThe monthly OGOR reports production, disposition, and well data for federal and Indian leases and must reconcile with sales.
Read → GlossaryMeasuring how much light a stack or flare plume blocks as a proxy for smoke - via Method 9 and COMS.
Read → GlossaryA beam of IR or laser light across an open span that catches any gas cloud crossing the line.
Read → GlossaryThe gauged volumes bracketing a period that, with receipts and deliveries, reveal throughput and gain or loss.
Read → GlossaryHow connected pipelines absorb interconnect measurement differences, and how SCADA cuts cash-out exposure.
Read → GlossaryThe hardware and software that monitors and controls physical processes - the world of PLCs, RTUs, and SCADA.
Read → GlossaryHow well an operator detects, diagnoses, and responds - and what drives it.
Read → GlossaryA step-by-step branching guide tied to an alarm, turning experts' tribal knowledge into repeatable response.
Read → GlossaryScheduled walkdowns where operators inspect equipment SCADA cannot see.
Read → GlossaryHow many assets one operator can effectively watch, and how exception-based SCADA expands the ratio.
Read → GlossaryHow an infrared camera makes hydrocarbon plumes visible as a fast alternative to component screening.
Read → GlossaryThe millivolt measurement of water's oxidizing state that controls biocide and chemical dosing.
Read → GlossaryHow analysts enrich, deduplicate, and prioritize a flood of OT alerts by process impact so a real intrusion is not buried.
Read → GlossaryA living record of every device on the OT network, because you cannot protect what you cannot see.
Read → GlossarySeeding a control network with fake PLCs, honeytokens and credentials so any interaction proves an intruder is present.
Read → GlossaryA decoy emulating a PLC or Modbus device to lure and record attackers, sitting safely off the real control network.
Read → GlossaryLearn who-talks-to-whom on which protocol, then flag deviations, using the determinism of control traffic.
Read → GlossaryHypothesis-driven search for a hidden intruder, using the deterministic nature of control traffic to shrink dwell time.
Read → GlossaryLogical segmentation on shared switches to split PLC, HMI, camera, and vendor traffic, and its limits versus a firewall.
Read → GlossaryAdministering OT network gear over a separate dedicated channel so admin traffic never shares the production data path.
Read → GlossaryHow SCADA pins a value at its range limit and flags Uncertain, hiding how far the process went, and why re-ranging is the fix.
Read → GlossaryAn as-found calibration failure and the impact review of every measurement since the last good check.
Read → GlossaryDevice-initiated links that reach cloud SCADA with no open inbound ports - and their security upside - explained.
Read → GlossaryHow high and low limits cap the manipulated variable, and how they must cooperate with anti-windup.
Read → GlossaryWhy switching a coil destroys output contacts, and how flyback diodes, RC snubbers, and MOVs suppress the spike.
Read → GlossaryRemotely updating field-device firmware with staged rollouts, A/B partitions, signed images, and rollback.
Read → GlossaryThe full API 2350 management system - procedures, alarms, AOPS vs MOPS, and risk categories - not just a switch.
Read → GlossaryThe independent high-high level layer required by API 2350 that trips an automatic shutoff before a tank overflows.
Read → GlossaryHow a high or low selector lets a constraint loop take over the valve to protect equipment without a full shutdown.
Read → GlossaryRedundant speed pickups slam the trip valve shut on excess speed to keep a bladed rotor from bursting.
Read → GlossaryWhen engineers deliberately drop to proportional-only or integral-only control, and the tradeoffs of each.
Read → GlossaryThe downhole seal that plugs the tubing-casing annulus - zonal isolation, permanent vs retrievable, and leak signs.
Read → GlossaryThe low-voltage distribution panel with main and branch breakers on a bus that feeds lighting, instruments, and small loads.
Read → GlossaryThe magnetic, non-consuming sensor that gives a highly accurate O2 measurement.
Read → GlossaryHow a PGS counts free spaces per zone, drives wayfinding signs, and aggregates occupancy for operators and apps.
Read → GlossaryComparing ultrasonic, camera, magnetometer and ramp-count methods and how detections roll up to the guidance controller.
Read → GlossaryClassic shaped-channel primary device that measures open channel flow from upstream depth, sized by its throat width.
Read → GlossaryEnergizes half a dual-winding motor first, then the rest after a short delay, cutting inrush with no transformer.
Read → GlossaryThe online test that moves an ESD valve partway to prove it is not stuck, without shutting the process down.
Read → GlossaryBuilding an OT inventory by listening to traffic instead of probing devices that active scans can crash.
Read → GlossaryThe algorithm that locates a taught model in a live image and reports its position, angle, scale, and match score.
Read → GlossaryReshaping a message between systems: renaming fields, converting units and format, and restructuring data to fit a target schema.
Read → GlossaryHow aromatics, CO2, heat, and run-dry attack a stator's elastomer, and the torque and temperature signs of it.
Read → GlossaryThe helical steel rotor and elastomer stator that form a PCP's progressing cavities, and how torque and rpm read them.
Read → GlossaryThe fixed diamond-cutter bit that shears rock instead of crushing it and drives modern drilling ROP.
Read → GlossaryThe rack or floor device that distributes, meters, and remotely switches power to control-room and server equipment.
Read → GlossaryThe share of controllers operators have flipped off automatic, the most telling number in a loop assessment.
Read → GlossaryThe dimensionless 0-100 percent view of a signal in its span, why HMIs use it, and span versus reading accuracy.
Read → GlossaryA processing deal where the producer takes a share of residue and NGL sales proceeds, not the physical product.
Read → GlossaryPunching flow paths through casing and cement with shaped charges - shot density, phasing, and plug-and-perf.
Read → GlossaryA short group of perforations within a stage, the entry point where fractures initiate - and a focus of limited-entry design.
Read → GlossaryThe head-versus-flow chart with speed lines bounded by the surge line and stonewall choke line.
Read → GlossaryPOTT and PUTT send a trip permit while DCB sends a hold-off, trading security against dependability.
Read → GlossaryThe formal written authorization gate before hazardous or non-routine field work begins.
Read → GlossaryHow a Petersen coil tunes the neutral so earth arcs self-extinguish, and how wattmetric SEF finds the faulted feeder.
Read → GlossaryWhy usable amp-hours shrink as you discharge faster, what the Peukert exponent means, and why C20 versus C100 breaks autonomy math.
Read → GlossaryHow fixed and switched kVAR banks supply reactive power locally to dodge utility penalties, plus resonance cautions.
Read → GlossaryThe 1oo1 formula, how architecture and proof-test interval change it, and summing subsystems to check the SIL.
Read → GlossaryThe safety metric for high-demand and continuous-mode functions, a failure frequency with its own SIL bands.
Read → GlossaryUnequal three-phase voltages or currents - why a small voltage unbalance overheats motors, and how it is measured and protected against.
Read → GlossaryUS federal pipeline safety regulator enforcing 49 CFR Parts 192 and 195, integrity management, and control room management.
Read → GlossaryA year-end inventory of pipeline miles by material and pressure plus facility counts, due June 15 on the Form 7100 series.
Read → GlossaryA UV-lamp gas instrument that reads low-ppm VOCs and benzene, distinct from a PID control loop.
Read → GlossaryGrabbing parts and placing them precisely with delta, SCARA, or gantry motion, vision guidance, and part feeding.
Read → GlossaryHow a controller runs a test to identify process dynamics and calculate its own gain, reset, and rate - and its limits.
Read → GlossaryHow proportional, integral, and derivative terms combine to hold a process at setpoint, plus tuning basics for oil and gas loops.
Read → GlossaryA composite 0 to 100 loop grade rolling up service factor, variability, oscillation, and valve travel.
Read → GlossaryWhat proportional gain, integral reset, and derivative rate each do, how they interact, and practical tuning trade-offs.
Read → GlossaryHow X-Y breakpoints and interpolation handle a nonlinear sensor or tank strapping table, versus one linear scale.
Read → GlossaryHow stress on quartz or PZT generates charge, why it makes sensors AC-coupled, and dynamic-only measurement.
Read → GlossaryRunning a device through a pipeline to clean it, separate products, or inspect the wall for corrosion and defects.
Read → GlossaryThe launching trap that loads a pig into a live pipeline.
Read → GlossaryThe receiving trap that catches a pig at the end of its run.
Read → GlossaryThe rubber-sleeve valve with a full-bore path and no metal in the flow - built for abrasive slurries, sand, and frac fluid.
Read → GlossaryThe field measurement that verifies cathodic protection against the -850 mV criterion.
Read → GlossaryThe gap between nominated and delivered gas, the intraday swing that creates it, and real-time gas control.
Read → GlossaryThe in-line tool that cleans, gauges, and inspects a pipeline while it runs.
Read → GlossaryThe compact small-volume prover with optical detectors and double-chronometry interpolation that resolves fractions of a meter pulse.
Read → GlossaryQuantifying the deepest localized corrosion pits, since maximum depth, not average loss, governs leak risk.
Read → GlossaryVelocity flow from stagnation pressure - the single-point insertion probe for flare and large-duct gas, and its limits.
Read → GlossaryA Prandtl probe combining total and static ports so one differential gives spot flow velocity.
Read → GlossaryThe localized attack that drills deep pits through steel while sparing most of the surface.
Read → GlossaryHow the end gun extends reach into corners, cam vs GPS sequencing, boosters, and automated arcs in a prescription.
Read → GlossaryThe Purdue Level 3 tier that aggregates historian, MES, and reporting data above the control network.
Read → GlossaryThe energy lost when NGLs are extracted from inlet gas, distinct from volumetric shrink and fuel, and how metering proves it.
Read → GlossaryThe quarter-turn tapered-plug isolation valve - lubricated vs sleeved types and why it suits gathering and slurry service.
Read → GlossaryThe multistage frac cycle of setting a plug, perforating, and fracturing each stage, with per-stage monitoring.
Read → GlossaryA supply-gas-driven methanol pump for sites with no power; drive-gas pressure sets its stroke rate.
Read → GlossarySwitches that report high or low versus transmitters that report the whole range, and how they layer for safety.
Read → GlossaryHow synchronous closing to the voltage zero crossing kills capacitor inrush, versus pre-insertion resistors.
Read → GlossaryThe star topology where one master radio polls many remotes over a single shared channel.
Read → GlossaryThe ratio of the 10-minute to 1-minute megohm reading, revealing moisture and aging a spot reading misses.
Read → GlossaryThe topmost smooth rod through the stuffing box, and the load measurement behind dynamometer cards.
Read → GlossaryHow neat or dry polymer is wetted, aged, and diluted into an active solution, and how SCADA controls the ratios.
Read → GlossaryThe two external floating-roof designs, and how buoyancy and rain or snow load drive the choice.
Read → GlossaryThe short sucker rods that space out a rod pump so the plunger strokes correctly within the barrel.
Read → GlossaryAbsolute-output versus change-per-scan PID forms, and why velocity eases bumpless transfer and windup.
Read → GlossaryThe device that makes a control valve hit its target - closed-loop positioning and smart valve diagnostics.
Read → GlossaryThe PD meter that counts trapped fluid pockets - why it beats velocity meters on viscous, low-flow service.
Read → GlossaryThe fixed-volume pump behind chemical injection and high-pressure water injection - why it needs relief protection.
Read → GlossaryPhysically blocking a line with spades and blinds for safe line-break work, beyond valve isolation.
Read → GlossaryHCDP computed from GC composition through an equation of state, highly sensitive to the C6+ characterization.
Read → GlossaryHow a site's maximum emissions decide major-versus-minor status and how enforceable throughput and runtime caps are tracked.
Read → GlossaryTally every load by current draw and duty cycle into a daily watt-hour figure that sizes your array and battery.
Read → GlossaryPredicting wind and solar output across horizons from weather models, plant history, and live SCADA data.
Read → GlossaryDelivering DC power and data on one cable to field radios and cameras, with 802.3af, at, and bt classes.
Read → GlossaryWhy paralleled supplies need an ORing module, how diode/MOSFET isolation works, and N+1 sizing with fail alarms.
Read → GlossaryHow relays block distance tripping on stable swings and trip to separate on unstable ones.
Read → GlossaryThe de-energized static checks done after mechanical completion and before live commissioning energizes a system.
Read → GlossaryThe top rung of the analytics ladder: not just predicting a failure but recommending the action to take.
Read → GlossaryThe log-log diagnostic whose derivative shape identifies wellbore storage, radial flow, and reservoir boundaries.
Read → GlossaryProducing a well at constant rate from a stabilized start and recording the pressure decline to get permeability and skin.
Read → GlossaryStepping a gauge down the well to read pressure at intervals, mapping fluid contacts, levels, and densities.
Read → GlossaryThe self-contained spring-and-diaphragm valve that holds downstream pressure with no power or controller.
Read → GlossaryThe inline restrictor that shields gauges and transmitters from spikes and pulsation, plus the over-snubbing tradeoff.
Read → GlossaryThe valve that holds a minimum upstream pressure, opening only to bleed off the excess.
Read → GlossaryThe discrete high or low pressure trip (PSH/PSL) behind wellsite ESD and pump-off shutdown logic.
Read → GlossaryClosed containers built to hold pressure - ASME Section VIII, MAWP, and relief - explained, from separators to knockout drums.
Read → GlossaryPumping slurry down casing and up the annulus for zonal isolation, and why the first job defines integrity.
Read → GlossaryThe gyrating-mantle crusher for high-tonnage primary duty and the signals SCADA trends to catch wear and faults.
Read → GlossaryThe allocation-of-record meter versus the meter that verifies it, which governs on disagreement, and live comparison.
Read → GlossaryWhy closed months reopen for meter corrections and late tickets, and how validated SCADA data shrinks them.
Read → GlossaryA documented restatement of a closed-period volume when a measurement error is found after the fact.
Read → GlossaryQualifying an uncertified device for a SIF using documented operating history instead of a certificate.
Read → GlossaryA ranked queue of the sites and assets needing attention, turning an alarm flood into ordered actions.
Read → GlossaryVaulting and brokering admin and vendor credentials so no human directly holds shared passwords.
Read → GlossaryWhat PFDavg measures, how it maps to SIL bands and the risk reduction factor, and why proof testing matters.
Read → GlossaryPure transport and measurement delay - the biggest limit on loop performance in pipelines and long lines.
Read → GlossaryA live simulation of the process itself, fed by real-time SCADA data, for what-if analysis and optimisation.
Read → GlossaryHow far the PV moves per unit of output - the process side of gain and why it forces gain scheduling.
Read → GlossaryThe tube where a stationary phase separates a gas sample by retention time; column choice and backflush set cycle time.
Read → GlossaryThe open-loop step response that yields gain, dead time, and time constant, and how to run it safely.
Read → GlossaryThe window between a hazardous deviation starting and reaching danger, and why the safety function must act inside it.
Read → GlossaryThe 63.2 percent response time (tau) read from a bump test - the input to Lambda and IMC tuning.
Read → GlossaryThe live measured signal a control loop reads back, and how it differs from setpoint and output.
Read → GlossaryWhy commingled streams metered only at a sales point are split back to wells through the allocation network.
Read → GlossaryHow operators close a daily volume balance across inlet, outlet, fuel, flare, and inventory, and act on the imbalance.
Read → GlossaryBarrels per day per psi of drawdown, the straight-line IPR measure whose trend flags damage or depletion.
Read → GlossaryThe IEC 61131-3 code building block - Program, Function, Function Block - behind reusable wellsite logic.
Read → GlossaryThe helical rotor-and-stator positive-displacement pump for viscous, gritty, and heavy-oil duty, and why torque and dry-run protection matter.
Read → GlossaryRotor-in-stator artificial lift for heavy oil and sand, in surface-drive and downhole-motor configurations.
Read → GlossaryFinding the longest test interval that still meets the target SIL, balancing integrity against cost and trips.
Read → GlossaryWhy a setpoint step spikes the output, and how acting on the measurement instead of error removes it.
Read → GlossaryThe inverse of gain (PB percent equals 100 over gain) and the DCS-versus-PLC unit confusion it causes.
Read → GlossaryFlow-proportional grab logic paced by flow-computer pulses that keeps a composite representative of the batch.
Read → GlossaryThe sand, resin-coated, and ceramic grains that hold fractures open, and how concentration is monitored.
Read → GlossaryThe switches that mark a prover's calibrated volume and define the counted pulses, and how wear corrupts a prove.
Read → GlossaryThe flow-reversing valve in a bidirectional prover whose double-block-and-bleed seal integrity protects every proof.
Read → GlossaryThe permanently installed proving subsystem - four-way valve, detectors, and taps - that a flow computer sequences for an auto prove.
Read → GlossaryConfirming the prover and its piping are liquid-full and gas-free before proving, and how trapped air corrupts the factor.
Read → GlossaryWhy a prover must be periodically re-water-drawn, what voids a certificate, and the cost of an expired one.
Read → GlossaryThe non-contacting eddy-current sensor that measures shaft vibration and position on fluid-film machines, feeding API 670 protection.
Read → GlossaryThe vault-mounted control valve that holds a fixed downstream pressure feeding a lower zone.
Read → GlossaryThe cellular sleep modes that let a battery RTU stay dormant for hours, their power savings, and the reachability trade-off.
Read → GlossaryThe suction and discharge bottles that smooth recip pressure waves to protect piping and metering.
Read → GlossaryRaw meter pulses, dual A/B pulse security, and the fidelity levels a flow computer verifies.
Read → GlossaryThe flow-speed, head-speed-squared, power-speed-cubed rules behind VFD energy savings and impeller trim.
Read → GlossaryTrapped gas in the impeller that stops a running pump moving liquid, its low-pressure symptoms, causes, and how to clear it.
Read → GlossaryRotating lead and lag roles to equalize pump runtime and wear, first-on/first-off and runtime-hour logic, and SCADA scheduling.
Read → GlossaryEnforcing a minimum off-time and maximum starts per hour so short-cycling does not overheat the motor or wear the starter.
Read → GlossaryHow a balance line and drum or disk cancel axial thrust in multistage pumps, and how a plug spikes thrust-bearing load.
Read → GlossaryThe vapor-bubble formation and collapse that erodes impellers, its gravel-like sound, and the pressure and vibration signs of it.
Read → GlossaryThe head-versus-flow performance curve whose intersection with the system curve sets a pump's operating point.
Read → GlossaryA low-low level or loss-of-flow trip that stops a pump before it runs dry and ruins its seal and bearings.
Read → GlossaryThe percent of the pump barrel filled with liquid each stroke, computed from the downhole card to drive pump-off control.
Read → GlossaryPicking the lowest-hour available pump as next lead so wear and maintenance intervals spread evenly across the group.
Read → GlossaryThe head a pump makes at zero flow, why it sets max discharge pressure, and how dead-heading overheats and damages a pump.
Read → GlossaryEnergy per unit volume pumped as a wire-to-water KPI, why it beats motor power for spotting wear and fouling, and trending it in a historian.
Read → GlossaryAdding and removing parallel pumps on demand, stage-up and destage setpoints and delays, and combining with a lead VFD trim pump.
Read → GlossaryHow a mainline station arbitrates flow, discharge-pressure, and suction-override modes, selecting the most restrictive.
Read → GlossaryHow the system resistance curve crosses the pump curve to fix the real operating point and flow.
Read → GlossaryA low-power trip that detects loss of prime, a closed valve, or run-dry, catching what a level switch misses.
Read → GlossaryReplaceable rings that hold a tight clearance to limit internal leakage, and how opening clearance cuts efficiency and flow.
Read → GlossaryDrawing, cooling, and returning tower liquid to remove heat and set internal reflux, balanced by flow and temperature loops.
Read → GlossaryThe double-reduction reducer that slows the prime mover to crank speed, rated by API peak torque.
Read → GlossaryThe polished-rod transducer that measures surface load to build dynamometer cards - wiring, calibration, and SCADA use.
Read → GlossaryA hazardous-area technique that keeps flammable gas out of an enclosure with clean-air purging and maintained positive pressure (Ex p).
Read → GlossaryA velocity or buoyancy device at a flare tip that cuts the sweep gas needed to keep air out, saving gas and CO2.
Read → GlossaryDeriving true density by filling a known volume and weighing it, the gravimetric reference for proving a densitometer.
Read → GlossaryA coated quartz crystal weighs water by frequency shift over a wet-dry cycle; contrast it with chilled mirror and TDLAS.
Read → GlossaryThe QTR plus configuration, event, and alarm logs and the constants to independently recompute the custody volume.
Read → GlossaryCombining consequence modeling with frequency data to produce individual-risk contours and F-N curves for a facility.
Read → GlossaryThe unavoidable half-LSB rounding error, and how 12-bit versus 16-bit cards change the step in real units.
Read → GlossaryFlushing the historian to disk before capture so the snapshot is application-consistent and restorable.
Read → GlossaryThe always-on standby draw of controllers and converters whose summed microamps can dominate a small solar node's budget.
Read → GlossaryThe third-party arbiter that breaks ties in a two-node cluster so one node stays primary and split-brain is prevented.
Read → GlossaryHow owner, integrator, controls, SCADA, and IT/OT roles divide who is responsible, accountable, consulted, informed.
Read → GlossaryThe constant-torque pneumatic actuator that is the standard automator for on-off ball and butterfly valves.
Read → GlossaryPower per cabinet in kW, why AI racks made density the binding constraint, and how PDU metering reveals the real number.
Read → GlossaryThe blind near-zone below a radar antenna, why nozzle ringing causes it, and how to mount and configure around it.
Read → GlossaryThe gauge locks onto a nozzle, coil, or condensation reflection and reports a false level; mapping and plausibility checks catch it.
Read → GlossaryThe core physics of non-contact radar level: a microwave round trip timed and converted to distance.
Read → GlossaryFixed rail-rack position where a tank car is spotted and loaded, with per-spot meter, valve, and overfill reporting to SCADA.
Read → GlossaryThe gravity media filter that polishes settled water by depth filtration on a backwash cycle.
Read → GlossaryHow it holds two flows in a fixed proportion using a wild and controlled stream, with combustion and blending examples.
Read → GlossaryThe block that computes a controlled-flow setpoint by multiplying a measured wild-stream flow by an operator-set ratio.
Read → GlossaryMapping a PLC analog input's ADC counts to real units with the two-point line equation.
Read → GlossaryThe RG correlation computes orifice Cd from beta, Reynolds number, and tap type, solved iteratively in the flow computer.
Read → GlossaryA live hydraulic model that flags leaks when measured pressures and flows diverge from prediction.
Read → GlossaryA chilled-water door coil that cools rack exhaust at the source for near-neutral heat rejection on dense racks.
Read → GlossaryThe exchanger that supplies boilup to a distillation column, with the steam, level, and temperature loops.
Read → GlossaryThe loop that sets lean-glycol purity and gas dew point while holding TEG below its ~400F thermal-degradation limit.
Read → GlossaryThe piston-driven gathering workhorse that boosts low-pressure wellhead gas - and why rod load sets its limit.
Read → GlossaryA legacy instrument that reads BTU by burning a metered slipstream, reconciled against a chromatograph in the historian.
Read → GlossaryThe maximum acceptable data loss measured in time, how it drives SCADA backup frequency, and RPO vs RTO.
Read → GlossaryThe maximum time a SCADA system may stay down before restore, and how it and RPO size your redundancy.
Read → GlossaryThe fast-opening antisurge valve that dumps discharge gas back to suction, with hot or cold recycle routing to protect the machine.
Read → GlossaryCapturing or combusting flowback gas during well completion instead of venting it - a Quad O procedure.
Read → GlossaryThe nominal environment where stated accuracy holds, and the influence errors real installations add on top.
Read → GlossaryThe overhead accumulator that splits condensed column overhead into reflux and product, setting purity.
Read → GlossaryStreaming a mine shelter's air, pressure, and headcount to surface so rescuers can see inside in an emergency.
Read → GlossaryAn active front end returns braking energy to the grid instead of burning it in a resistor, and cuts harmonics.
Read → GlossaryA region is a geographic location; an AZ is an isolated data centre within it that provides failure isolation.
Read → GlossaryHardware-latched position capture on a mark sensor that corrects an axis to a feature on the fly.
Read → GlossaryThe tamper-evident chain from raw sensor reading to submitted number that lets a filing survive an audit or enforcement.
Read → GlossaryHow RVP relates to true vapor pressure, why volatility drives tank flash losses, and how stock RVP informs emission estimates.
Read → GlossaryThe air blast, pusher, or diverter that removes a failed part, plus the tracking and confirmation that make it reliable.
Read → GlossarySpecific gravity is a molar mass ratio to air; relative density is the real-density ratio, and they diverge for heavy or CO2-rich gas.
Read → GlossaryIdeal is a molar-mass ratio, real includes compressibility; the AGA 8 gross methods expect a specific basis or the volume biases.
Read → GlossaryA table that quantifies loop interaction so you can pair the right manipulated and controlled variables.
Read → GlossaryHow the governing overpressure scenario - fire, blocked outlet, valve failure - sets the required relief rate.
Read → GlossaryStarting, stopping, and VFD-regulating an irrigation pump over telemetry, with dry-run protection and staging.
Read → GlossaryThe oil-filled tube linking a diaphragm seal to the transmitter, whose length and temperature drive response time and zero shift.
Read → GlossaryThe actuated wellhead valve that fails safe closed and can be commanded shut from the control room.
Read → GlossaryCharacterize base draw, intermittent spikes, and seasonal load so average sizes storage and peak sizes wire.
Read → GlossaryHow sanitization kiosks and USB port lockdown stop malware entering air-gapped sites through drives.
Read → GlossaryOne reusable report design driven by parameters like site, date, and tag set to generate a per-well report for a whole field.
Read → GlossaryWhy sampling fast but reporting sparsely on change keeps resolution high while cutting bandwidth.
Read → GlossaryWindup from manual, cascade saturation, and clamps, and how back-calculation and tracking prevent it.
Read → GlossaryRunning a resettable period total alongside a permanent grand total that never clears, with safe reset logic.
Read → GlossaryThe risk left after all protection layers, and why it must sit at or below the tolerable target.
Read → GlossaryHow tailgate pipeline-quality gas is measured, quality-checked, and allocated after fuel, flare, and NGL shrink.
Read → GlossaryA rugged transformer-based position sensor using sine/cosine windings decoded by a resolver-to-digital converter.
Read → GlossaryHow a neutral CT versus phase-CT residual catches winding-to-earth faults near the star point.
Read → GlossaryThe timer that keeps its accumulated value when its rung goes false - and needs an explicit reset.
Read → GlossaryThe backwards phase behavior where dropping pressure forms liquid, driving gathering-line liquid dropout.
Read → GlossaryWhy self-announcing failures are managed by repair while hidden dormant failures drive proof-test frequency.
Read → GlossaryThe certified, sealed, high-accuracy electric meter a utility uses to bill for energy, like a custody-transfer flow meter.
Read → GlossaryWhen 4 mA is the high value and 20 mA the low, the negative slope in the equation, and the backward-reading symptoms.
Read → GlossaryA gateway dials out to a rendezvous server so engineers can reach a site without opening any inbound firewall ports.
Read → GlossaryAn automatic reverse or oscillation of a VFD pump that sheds rags when rising power or falling flow signals a clog.
Read → GlossaryThe gain-minus-loss math that predicts whether a SCADA radio link will actually close.
Read → GlossaryThe sacrificial wear band that carries the piston weight and keeps it off the cylinder bore.
Read → GlossaryThe primary and secondary seals that close the roof-to-shell gap and control fugitive emissions.
Read → GlossaryThe likelihood-by-consequence grid that ranks scenarios, how cells map to tolerable risk, and calibration pitfalls.
Read → GlossaryThe inverse of PFDavg engineers actually talk in, its SIL bands, and how it links LOPA to SIL verification.
Read → GlossaryCombining probability and consequence of failure to prioritize inspection and set risk-based intervals.
Read → GlossaryTracking piston-rod position with a proximity probe to predict rider-band wear before bore contact.
Read → GlossaryThe combined gas and inertia force on a recip compressor's piston rod, and its frame-rating limit.
Read → GlossaryThe stacked sealing rings that seal the moving piston rod, and the vent trend that flags a rebuild.
Read → GlossarySucker rod (beam) pumping and the pumpjack - how reciprocating rods lift oil, plus dynamometer cards and pump-off control - explained.
Read → GlossaryThe per-revolution load reversal that re-oils a recip compressor's crosshead pin bearing.
Read → GlossaryA tailored view per role - operator, engineer, executive - drawn from the same data, right metrics per seat.
Read → GlossaryA moving average that smooths noisy data over a sliding window - simple vs exponential, and how window size trades off.
Read → GlossaryThe flexing drain that carries rainwater off a floating roof, and why a blocked one can sink it.
Read → GlossaryThe legs that support a floating roof off the bottom, the landing-loss event, and usable inventory.
Read → GlossaryThe tapered-tube-and-float variable-area meter for chemical injection and purge flows - a powerless local flow indicator.
Read → GlossaryThe tool that steers a well while the string keeps rotating, using push-the-bit or point-the-bit control.
Read → GlossaryThe two LTE reference-signal metrics a technician reads when siting an antenna, and how they differ from RSSI.
Read → GlossaryThe custody-transfer record of a crude oil sale - what it contains, tank vs LACT tickets, and why it is the basis of payment.
Read → GlossaryMatch each ticket and LACT proving to the settlement statement, anchored in continuous tank and meter data, to catch underpayments.
Read → GlossaryUsable amp-hours divided by average load, corrected for the Peukert effect, and predicted live by a SCADA host.
Read → GlossaryThe fast recognition of a major pipeline failure for rapid shutdown.
Read → GlossaryA jerk-limited velocity profile that ramps acceleration smoothly to cut shock, vibration, and settling time.
Read → GlossaryThe magnesium or zinc anode that corrodes in place of steel in galvanic cathodic protection.
Read → GlossaryThe highest level a tank can reach without overflow once response time and inflow are subtracted from the top.
Read →Merobix is cloud SCADA for oil & gas - it reads the instruments and protocols defined here into one dashboard.
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