Flow meters, custody transfer, orifice and Coriolis metering, AGA/API MPMS, and gas quality. 173 terms in this topic - each defined in plain English on its own page.
Flow meters, custody transfer, orifice and Coriolis metering, AGA/API MPMS, and gas quality.
Multi-rate proving that linearizes a turbine or Coriolis meter across its flow range, applied live.
Read → GlossaryThe contractual custody-transfer record of a proving - factors, runs, corrections, and sign-offs.
Read → GlossaryThe theoretical maximum gas rate at zero flowing pressure, established by backpressure and isochronal deliverability tests.
Read → GlossaryThe AGA 3 / API 14.3 standard defining the orifice plate, meter tube, and flow equation for gas.
Read → GlossaryThe AGA 7 standard governing how gas turbine meters are installed, pulse-counted, and calibrated.
Read → GlossaryThe AGA 8 method that computes compressibility Z and gas density from composition, behind Fpv.
Read → GlossaryFull molar composition versus bulk properties for computing Z, when each fits, and how the wrong choice biases volume.
Read → GlossaryThe AGA 9 standard for multipath ultrasonic gas meters used in custody transfer measurement.
Read → GlossaryAGA 11, also API 14.9, governs Coriolis meters in gas custody, inferring base volume from mass and composition density.
Read → GlossaryAGA 5 determines fuel gas heat value and total energy, tying heating value to volume to produce delivered MMBtu.
Read → GlossaryThe American Gas Association reports (AGA 3, 7, 8, 9) that define how natural gas flow is measured and calculated for custody transfer.
Read → GlossaryThe Manual of Petroleum Measurement Standards: its chapter structure and how proving, sampling, and correction connect.
Read → GlossaryChapter 11.1 gives the equations behind the 6A/54B tables that correct observed liquid volume to net at 60 degF.
Read → GlossaryCapturing the meter's performance before adjustment, and why it drives bias and prior-period decisions.
Read → GlossaryThe Fb geometry term in the AGA 3 orifice equation and the corrections a flow computer layers on top.
Read → GlossaryThe bore to pipe diameter ratio that sets orifice meter accuracy and is a commonly misconfigured constant.
Read → GlossaryThe instrument that measures gas heating value and Wobbe index for custody and energy billing - calorimeter vs GC.
Read → GlossaryDividing a lumped heavy-end peak into fixed hexane, heptane, and octane fractions that shift heating value and density.
Read → GlossaryThe fixed-ratio rule that divides a lumped hexanes-plus GC peak into hexane, heptane, and octanes-plus, changing computed BTU.
Read → GlossaryThe carrier bottle depletes and a falling pressure shifts retention times before runout, so trend it to schedule changeouts.
Read → GlossaryHow clean the helium or hydrogen carrier is; contamination raises baseline noise and skews custody composition and BTU.
Read → GlossaryExternal ultrasonic transducers that read flow through the pipe wall with no cut and no shutdown.
Read → GlossaryFiring pulses through the pipe wall and timing the upstream-downstream difference, plus V, W, and Z beam paths.
Read → GlossaryHow reversing flow through a precolumn lumps the heavies as C6+ and shortens cycle time, and how mistimed valves corrupt BTU.
Read → GlossaryThe wet-weather discharge of untreated sewage and stormwater when a combined system is overwhelmed.
Read → GlossaryA layered method - power, link, path, protocol, device - with ping, loopback, and poll counters to bisect and localize the break.
Read → GlossaryA multi-bore orifice plate that conditions the flow itself, cutting the upstream straight-run needed in tight piping.
Read → GlossaryWhy fluid through a vibrating tube twists it, and how the phase shift yields true mass flow directly.
Read → GlossaryA mass flow meter that reads flow directly from a vibrating tube and also measures fluid density - ideal for custody transfer.
Read → GlossaryA shift in the no-flow reference so the meter reads flow at zero flow or biases totals; trend no-flow windows to catch it.
Read → GlossaryEntrained gas or flashing decouples the tube vibration, spiking drive gain and collapsing mass and density accuracy.
Read → GlossaryPressure sensed right at the plate faces, often via annular chambers, common in ISO 5167 and small-bore lines.
Read → GlossaryThe fiscal metering point where ownership of oil or gas passes between parties, held to strict accuracy and audit standards.
Read → GlossaryPackaged metering system: parallel runs, flow computers, densitometer, sampler, and prover connections reporting to SCADA.
Read → GlossaryA short, high-recovery DP element giving a strong signal for low permanent pressure loss, saving pumping energy.
Read → GlossaryHow a frequency shift off suspended particles reveals velocity, and why Doppler needs dirty fluid, not clean.
Read → GlossaryReads the frequency shift off bubbles and particles; built for slurries and aerated produced water.
Read → GlossaryHow the water-content assumption shifts Btu per cubic foot across the dry, saturated, and as-delivered bases.
Read → GlossaryAn offset-bore orifice plate that lets sediment, condensate, or gas pass without fouling the plate in dirty service.
Read → GlossaryAn existing pipe bend becomes a rough flow meter by tapping the inner and outer radius for centrifugal DP.
Read → GlossaryA flow computer that ingests live GC composition, computes heating value, and integrates BTU against corrected volume every period.
Read → GlossaryThe per-interval multiply of corrected volume by heating value into MMBtu; store the volume, HV, and energy triplet to audit it.
Read → GlossaryHow a conductive fluid moving through a magnetic field induces a velocity-proportional voltage - the magmeter principle.
Read → GlossaryWhere orifice DP is sensed, why tap location changes the Cd equation, and why the flow computer must match the taps.
Read → GlossaryThe capacity number that sizes a valve for a given flow and pressure drop, with its metric equivalent Kv.
Read → GlossaryThe logs that record every constant value and parameter change so a flow computer's volumes stay auditable.
Read → GlossaryThe tube-bundle or perforated-plate insert that removes swirl and flattens the velocity profile to shorten meter runs and hold accuracy.
Read → GlossaryThe safety-critical divert valve, its dual-stem proof-of-closure, and why its state is the most audited HTST signal.
Read → GlossaryThe validation, estimation, and editing quality gate analysts run on raw EFM data before volumes are booked.
Read → GlossaryA contoured-throat DP element between an orifice and a venturi, built for high-velocity steam service.
Read → GlossaryThe discrete no-flow or low-flow detector for pump dry-run and cooling-loss protection.
Read → GlossaryHow a flow computer accumulates flow time and interpolates a multi-point curve so meter factor varies with rate, versus a fixed K-factor.
Read → GlossaryFlow-proportional versus residual and compound-loop dosing, and how a flow signal paces a metering pump in SCADA.
Read → GlossaryModulating a variable-speed pump to match inflow and hold a near-constant level, smoothing discharge to the plant.
Read → GlossaryA daily heating value weighted by flow volume, accumulated interval by interval, avoiding the error of naive time-averaging.
Read → GlossaryThe BTU average that weights each analysis by the volume flowing during its cycle, and why it diverges from a time average.
Read → GlossaryFlow-weighting weights each sample by flow so idle periods do not skew the average; API 21.1 requires it for volume variables.
Read → GlossaryThe pressure at the reservoir face while a well produces, setting drawdown and locating the well on its inflow curve.
Read → GlossaryThe square root of Z base over Z flowing, a distinct orifice-equation multiplier that shifts volume at high pressure.
Read → GlossaryHow turbine blade-passage pulses and the K-factor become custody volume in a flow computer.
Read → GlossaryThe stable, symmetric velocity shape flow meters assume; elbows and valves distort it with swirl and asymmetry.
Read → GlossaryThe instrument that measures natural gas composition to set BTU and correct custody-transfer flow - how a GC works.
Read → GlossaryThe real-gas correction to the ideal gas law that feeds flow-computer supercompressibility and gas volume calculations.
Read → GlossaryThe AGA 3 term that corrects for gas thinning across the orifice plate, and why a wrong Y biases custody volumes.
Read → GlossaryWhether a gas burns acceptably in equipment tuned for a reference gas, held online by Wobbe bands and flame indices.
Read → GlossaryHow often an online chromatograph produces a fresh composition, how it feeds the flow computer, and GC fault behavior.
Read → GlossaryA non-adjusting check that injects a known gas, compares, and logs pass or fail without changing the operating calibration.
Read → GlossaryResidual heavy components carried into the next cycle create ghost peaks that inflate composition and bias heating value between streams.
Read → GlossaryHow a chromatograph scales mole percents to sum to 100, the acceptance window, and why it can mask calibration drift.
Read → GlossaryHow tightly a chromatograph holds column temperature; drift shifts retention times and can misidentify custody peaks.
Read → GlossaryThe per-component factor turning peak area into mole percent, why it drifts, and how SCADA should trend and alarm on it.
Read → GlossaryThe per-component multiplier that turns peak area into mole percent, why it silently biases BTU, and how a host trends its drift.
Read → GlossarySharing one custody GC across several meter runs through a selector, with a stabilization purge to prevent carryover.
Read → GlossaryThe raw pre-normalization mole percent sum is the best real-time GC health check; alarm on its drift from one hundred.
Read → GlossaryFlow-to-open versus flow-to-close on a globe valve, the trade-offs, and why the body arrow must be respected.
Read → GlossaryThe BTU-per-cubic-foot figure that converts measured gas volume into the MMBTU energy that gets billed.
Read → GlossaryHow observed liquid becomes gross standard volume and then net oil after water and sediment - and why the split matters.
Read → GlossaryHolding last good composition, a contractual default, or a nearby analyzer to keep energy computing while the GC is offline.
Read → GlossaryAn instrument that quantifies a component leak in scfh, feeding emissions inventories and repair prioritization.
Read → GlossaryEstimating heating value from physical properties instead of a full GC, cheaper and continuous but checked against periodic analysis.
Read → GlossaryCorrelative methods estimate gas energy from a few properties like speed of sound and CO2 instead of a full component GC.
Read → GlossaryThe curve linking a well's rate to bottomhole flowing pressure, and how PI and Vogel shape it.
Read → GlossaryA single-point velocity probe that infers average flow, with a hot-tap install advantage on large lines.
Read → GlossaryThe integral value is the square root of hw times Pf that a flow computer integrates each second to build orifice volume.
Read → GlossaryA small precision orifice close-coupled to a DP transmitter for low flows in small-bore lines.
Read → GlossaryMinimum upstream and downstream straight lengths, keyed to fitting and beta, so an orifice plate meets its stated uncertainty.
Read → GlossaryThe international method computing calorific value, density, and Wobbe index from composition, where reference bases decide the result.
Read → GlossaryThe pulses-per-unit-volume constant that turns a turbine or PD meter's pulses into volume - and how it differs from meter factor.
Read → GlossaryThe automated skid that meters, samples, and quality-checks crude oil at the point ownership transfers from lease to pipeline.
Read → GlossaryMany small passages keep flow laminar so DP is linear with flow, giving wide-turndown low-flow gas measurement.
Read → GlossaryThe DP threshold below which a flow computer calls flow zero, killing square-root noise that creates phantom volume.
Read → GlossaryThe Faraday-induced voltage pickup in a magnetic flow meter, plus wetted vs capacitive types and fouling.
Read → GlossaryThe obstructionless mag meter behind produced-water and disposal-well flow - Faraday's law and its conductivity limit.
Read → GlossaryProving a meter with a proven reference meter in series - no dedicated prover, and its accuracy limits.
Read → GlossaryHow the uncertainty on custody net volume is built up from level, temperature, density, and water-cut errors - and where to tighten it.
Read → GlossaryThe correction multiplier from a prove that aligns a flow meter's output with a reference - and how it differs from K-factor.
Read → GlossaryApplying SPC limits to successive factors to separate normal scatter from a real meter shift.
Read → GlossaryGradual wear-driven factor creep versus an abrupt step, and how trending catches it before OOT.
Read → GlossaryThe prover volume, temperature, pressure, density, and pulse-count contributions and how they roll up.
Read → GlossaryVerifying a flow meter against a known-volume prover to produce its meter factor - the basis of trusted custody transfer.
Read → GlossaryWobbe governs burner heat release and methane number governs engine knock, so a gas can pass one and fail the other.
Read → GlossaryEstimating leakage from a DMA's lowest overnight inflow after subtracting legitimate night use.
Read → GlossaryThe MPFM that meters oil, gas, and water together without separation - how it works and why it replaces test separators.
Read → GlossaryGross counts the heat from condensing combustion water, net does not, and confusing them misstates energy.
Read → GlossaryAccumulating gross measured volume versus net volume after per-interval water, shrinkage, and temperature correction.
Read → GlossaryThe timer that stops flow-time accrual and declares a run idle after DP stays below cutoff.
Read → GlossaryThe legacy Fpv correlation from gravity, CO2, and N2 that predates AGA 8 and biases high-pressure, inert-rich meters.
Read → GlossaryMeter that derives gravity flow from the water depth over a flume or weir using a head-to-flow equation.
Read → GlossaryThe empirical factor relating actual to theoretical orifice flow, computed iteratively from beta ratio and Reynolds number.
Read → GlossaryA small drain hole at the bottom or vent hole at the top of an orifice plate that passes a nuisance second phase.
Read → GlossaryA dulled upstream bore edge raises the discharge coefficient and biases orifice flow high, threatening custody accuracy.
Read → GlossaryA walk through the AGA 3 mass flow equation and its iterative discharge-coefficient solution.
Read → GlossaryA differential-pressure flow meter that infers flow from the pressure drop across a plate - the AGA 3 standard for gas.
Read → GlossaryWhy the upstream edge must stay sharp and square, how nicks and warping skew flow, and how inspection protects volumes.
Read → GlossaryPulling and checking a plate for edge sharpness, bore size, and cleanliness per AGA 3 to keep gas measurement accurate.
Read → GlossaryA rounded edge or worn bore shifts the discharge coefficient and silently biases AGA-3 flow; trending against a check meter reveals it.
Read → GlossaryCombine Cd, expansibility, diameters, DP, pressure, temperature, and density via sensitivity coefficients by root-sum-square.
Read → GlossaryMeshing oval gears count fixed volumes as pulses for accurate viscous-fluid and chemical-dosing metering.
Read → GlossaryThe flow-per-area parameter that decides whether floc settles, and how it is watched in SCADA.
Read → GlossaryThe unrecovered head across a flow element; orifices lose most of the DP, venturis and cone meters recover it.
Read → GlossaryHow a multi-element probe steers and focuses beams to image welds and map corrosion in a single pass.
Read → GlossaryMoving dashes or arrows on a pipe graphic that show fluid is flowing and in which direction.
Read → GlossaryThe diagnostic ratio built from path velocities that reveals an abnormal flow profile.
Read → GlossaryPacing a dosing pump to production so concentration stays constant as rate swings, closed by the RTU.
Read → GlossaryRun repeat prover passes at operating flow, count pulses against certified volume, and accept a meter factor only when it repeats.
Read → GlossaryHow operators decide how often to prove a meter, and how SCADA schedules and trends proves.
Read → GlossaryWhy a pump must stay above minimum continuous flow, and how recirculation lines and ARC valves protect it.
Read → GlossaryEnd-of-curve operation at high flow and low head that overloads the motor and can cavitate, and how telemetry catches it.
Read → GlossaryA quarter-circle inlet orifice plate that keeps its coefficient stable at low Reynolds numbers for viscous fluids.
Read → GlossaryHow source-tag quality flows into derived points with worst-input-wins, and why ignoring it misleads.
Read → GlossaryThe API 21.1 quantity, configuration, and event logs a flow computer keeps so a measurement can be audited.
Read → GlossaryThe status marker that flags a suspect composition or energy interval after a GC fault and drives measurement editing under API 21.1.
Read → GlossaryDecision guide: radar tolerates the foam, vapor, and condensation of a sewage wet well that fool a cheaper ultrasonic sensor.
Read → GlossaryRadius (D and D/2) taps sense pressure one diameter upstream and a half diameter downstream, near the vena contracta.
Read → GlossaryA plate that reduces pressure or limits flow rather than measuring it, often multi-stage to avoid cavitation.
Read → GlossaryThe dimensionless number that classifies laminar versus turbulent flow and shifts discharge coefficients and meter accuracy.
Read → GlossaryScanning a QR or NFC tag on equipment to instantly pull its data, history, and the right form, removing wrong-asset errors.
Read → GlossaryA crescent-opening orifice plate that hugs the pipe wall to pass slurry, solids, or gas in the dirtiest service.
Read → GlossaryThe dual-chamber fitting that lets you pull and inspect an orifice plate under pressure without shutting in the meter.
Read → GlossaryWhen a steep downhill runs partially full, why it hurts measurement, and how back pressure fixes it.
Read → GlossaryWhy DP-based flow follows the square root of pressure, where to extract, and how to avoid double-rooting.
Read → GlossaryThe total pressure where a fluid stops, static plus dynamic, and the basis of pitot and annubar readings.
Read → GlossaryAn automatic wet-weather mode that raises start levels and calls all pumps, favoring capacity over efficiency.
Read → GlossaryThe undisturbed pipe length in diameters a meter needs, why fittings distort flow, and conditioners.
Read → GlossaryThe Fpv real-gas correction from AGA 8, its link to the z-factor, and its impact on billed gas volume.
Read → GlossaryA disc in the pipe senses drag force, so target meters handle dirty and viscous fluids that clog orifice plates.
Read → GlossaryA laser-absorption H2S analyzer with no consumable tape, giving fast, low-maintenance custody measurement and real-time SCADA spec enforcement.
Read → GlossaryA wellbore temperature log run during flow that spots fluid entry, crossflow, and leaks by departures from the geothermal gradient.
Read → GlossaryThe combined nitrogen and CO2 fraction that dilutes heating value, why tariffs cap it, and how a host trends it against the limit.
Read → GlossaryHow root sum square combines meter, transmitter, pressure, and temperature errors into one custody figure.
Read → GlossaryMeasures all sulfur species, H2S plus mercaptans and COS, against a contract limit, unlike an H2S-only analyzer.
Read → GlossaryTimes sound with and against the flow for velocity; clean-fluid, no-pressure-drop custody metering.
Read → GlossaryA flow meter whose rotor spins in proportion to velocity, giving high accuracy and wide rangeability under AGA 7.
Read → GlossaryThe max-to-min ratio over which a meter or valve stays accurate, deciding whether one meter covers a well's whole life.
Read → GlossaryUsing airborne ultrasound to detect corona, tracking, and arcing in switchgear before flashover.
Read → GlossaryA no-moving-parts meter that derives flow from the transit-time difference of sound pulses, used for gas custody under AGA 9.
Read → GlossaryThe non-contact echo level sensor for tanks and sumps - how it works and why vapor and foam limit it.
Read → GlossaryComparing measured speed of sound against the AGA 10 value as a live custody meter health check.
Read → GlossaryHow a multipath meter checks gain, SNR, path velocities, and speed of sound to flag drift.
Read → GlossaryBubbles, solids, attenuation, or fouled transducers drop measurement paths; alarm on per-path SNR and gain, not just flow.
Read → GlossaryWhy the raw pre-normalization sum near 100 is the best early warning of carrier loss or valve leak, and how to alarm on it.
Read → GlossaryThe UT gauge method that measures remaining pipe and vessel wall at fixed inspection points.
Read → GlossaryA DP meter with a centered cone that conditions flow, tolerating short straight run and dirty service.
Read → GlossaryLinear, equal-percentage, and quick-opening curves - and why the wrong one makes a loop hunt at part-stroke.
Read → GlossaryThe point of minimum jet area and lowest pressure past an orifice plate that drives tap placement and Cd.
Read → GlossaryBlending fuel gas into a lean vent stream to lift its heating value above the threshold for reliable flare combustion.
Read → GlossaryRun the tube-stiffness diagnostic, do a proper stopped-flow zero at process temperature, and cross-check indicated density.
Read → GlossaryDo a full-pipe no-flow zero, check coil and electrode resistance, test insulation, and prove the converter with a simulator.
Read → GlossaryHow a model infers flow from pressure, temperature, and choke position for allocation and well surveillance.
Read → GlossaryThe vortex-shedding meter for steam, fuel gas, and clean liquid - the von Karman principle and its low-flow cutoff.
Read → GlossaryA DP meter with a V-shaped restriction for viscous, abrasive, and slurry fluids that plug an orifice.
Read → GlossaryWhen both parties observe a proving and jointly accept the meter factor and report.
Read → GlossaryThe interchangeability figure - heating value over root specific gravity - that says whether one gas can substitute at a burner.
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