Alberta OilNEWS · MARKETS · INDUSTRY
Explore
← All equipment

INSTRUMENTATION / INTERACTIVE 3D

Venturi flow-meter concept

Follow a continuous hollow passage through a converging section, throat and diffuser, with two independent pressure-tap lines.

Static preview of the venturi flow-meter concept schematic
Loading the 3D model…

Drag to orbit · Scroll or pinch to zoom · Select a visible part or use the parts list. Keyboard: focus the view and use arrow keys to orbit.

TRY THE RELATIONSHIP

Why a narrower throat changes pressure.

IDEAL FLOW EXPLORER

Change the inputs and compare two sections of an ideal tube. This diagram has its own dimensions; the controls do not resize or simulate the 3D assembly above.

Assumptions: steady flow, constant density, no friction, no heat or shaft work, equal elevation, and a one-dimensional mean-velocity approximation. No real-fluid loss or calibration is included.

Slider limits keep this example readable. They are not equipment limits or a recommended operating range.

Ideal tube sectionsA wide inlet narrows to a throat, then widens to an equal-area outlet. The numeric table gives area, mean velocity and relative static pressure.InletThroatOutletEqual flow through all three sections
Inlet mean velocity0.637 m/s
Throat mean velocity2.546 m/s
Inlet − throat static pressure3.040 kPa

At 5 L/s, the ideal throat velocity is 2.546 m/s and its static pressure is 3.040 kPa below the inlet.

Ideal comparison — static pressure relative to the inlet
SectionArea (cm²)Mean velocity (m/s)Static pressure change (kPa)
Inlet78.5400.6370.000
Throat19.6352.546-3.040
Equal-area outlet78.5400.6370.000
See the equations and what the ideal outlet means

Area A = πD²/4. Throat diameter d = βD, so A₂ = β²A₁. With constant density, volume flow Q = A₁v₁ = A₂v₂. Bernoulli's ideal relation gives p₁ − p₂ = ½ρ(v₂² − v₁²).

Doubling Q at fixed areas doubles both velocities and makes this ideal pressure difference four times larger. Equal outlet and inlet areas give equal velocities and static pressures in this lossless example. A real diffuser does not guarantee complete pressure recovery.

These calculated values are an independent arithmetic example, not readings from the exported model or a real meter. There is no absolute inlet pressure, vapor-pressure test, discharge coefficient, uncertainty, viscosity, compressibility or multiphase model. No equipment selection, calibration or operating conclusion follows.

Principle references: NASA Glenn: Bernoulli equation and assumptions ↗ · NASA Glenn: mass conservation ↗. The interface and diagram are original; no source artwork was imported.

HOW TO READ THIS MODEL

The system, explained.

A Venturi is a differential-pressure flow-measurement element. DwyerOmega describes a constriction, increased velocity and a pressure difference used to infer flow. Our original static model makes the passage inspectable: a cylindrical inlet narrows through a converging region to a smaller throat, then expands through a diverging region to an outlet. Two real wall openings reach separate hollow line envelopes at the upstream and throat locations. The open lines end independently; no transmitter, differential reading or flow calculation is supplied. The model has 85 named mesh instances, including separate paired flanges, gasket locations, smooth joint hardware, support feet and an external direction arrow. Use Half section to inspect the passage while retaining the complete original model.

Model scope and limits

Original invented static geometry, with five hollow passage regions and two independent pressure-tap paths. Selected fresh GLB checks establish five clear axial rays across all parts, ten actual nested end cross-sections, connected tap geometry, true component openings and retained walls. The illustration uses a front presentation cutaway. No source CAD/figures, product dimensions, specified tap positions, standard flange pattern, material, rating or procedure adopted. No calculated flow/pressure, discharge coefficient, density, Reynolds-number range, recovery/loss result, calibration, uncertainty, selected fit, leakage, compatible installation, straight-run requirement or operating/service qualification.

Further reading: DwyerOmega: general Venturi and differential-pressure vocabulary; no source figures, dimensions or ratings imported ↗

Source links support further study; no affiliation or endorsement is implied.

CHECK YOUR UNDERSTANDING

What do the two pressure-tap lines establish in this original model?

Choose an answer

GUIDED COMPONENT STUDY

Trace the system.

Read each explanation, then focus its component in the explorer. This is a learning route through the model, with no operating or maintenance sequence.

  1. Find the upstream passage

    The larger straight bore leads to the converging region. An actual upper wall opening reaches the independent upstream tap. Invented length supplies no required straight-run specification.

  2. Follow the narrowing wall

    Nested inner and outer surfaces narrow to the throat. Ten sampled end sections across the five passage regions are checked from actual imported vertices. This is geometry, not a velocity or pressure solution.

  3. Inspect the throat

    The smaller cylindrical region has a real open axial lumen and a drilled upper pressure-tap opening. Its invented radius establishes no selected diameter ratio, calibration or coefficient.

  4. Follow the expanding wall

    The passage expands from the throat to the downstream bore. Its longer original taper is a teaching choice; no recovery, permanent loss, separation or erosion calculation is supplied.

  5. Find the downstream boundary

    The outlet remains hollow. A separate companion flange and short boundary spool make the independent end connection visible. No adjacent plant or qualified installation is specified.

  6. Trace the upstream pressure location

    A real hollow neck overlaps the drilled wall location and reaches a straight line envelope. Selected exported rays check the geometric route, without establishing a leak-tight or rated joint.

  7. Trace the throat pressure location

    The second hollow neck reaches the throat wall opening. Its location identifies a separate pressure path; the model contains no fluid fill, pressure data or response.

  8. Keep a line separate from a reading

    This hollow line ends independently at an open collar. No transmitter, manifold, isolation arrangement, electrical signal or measured differential is connected.

  9. Compare the paired flanges

    Six true openings occupy invented joint locations. The companion flange is separate, as are smooth studs, bored washers and nut envelopes. Their count and size do not designate a flange standard or pressure class.

  10. Distinguish a gasket location

    This annular region retains a real central opening with deliberate gaps from adjacent flanges. Material, compression, fit and leakage performance are unspecified.

  11. Keep support separate from measurement

    The foot has two actual anchor-location bores and separate smooth hardware. No foundation, embedment, structural load or fitted saddle is specified.

  12. Read the arrow as an annotation

    The static arrow lies outside the passage. It labels the invented reading direction through inlet, throat and outlet. It does not visualize velocity, a measured rate or moving fluid.

Additional primary references: DwyerOmega: undated general Venturi principle, read September 27; no source art, dimensions, ratings or procedures imported ↗

ACCESSIBLE COMPONENT REFERENCE

Every part, in plain language.

Search all components ↗Model provenance ↗
Upstream cylindrical passage

Separate hollow axial passage region with real nested surfaces and invented proportions. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Converging passage

Separate hollow axial passage region with real nested surfaces and invented proportions. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Throat passage

Separate hollow axial passage region with real nested surfaces and invented proportions. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Diverging passage

Separate hollow axial passage region with real nested surfaces and invented proportions. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream cylindrical passage

Separate hollow axial passage region with real nested surfaces and invented proportions. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream pressure-tap neck

Hollow pressure-tap location reaching the drilled passage wall; no selected tap diameter or connection. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream pressure-line envelope

Open straight pressure-line envelope terminating independently; no connected transmitter, fluid fill or response. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream line-end collar

Separate bored terminal collar without threads or selected fitting. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Throat pressure-tap neck

Hollow pressure-tap location reaching the drilled passage wall; no selected tap diameter or connection. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Throat pressure-line envelope

Open straight pressure-line envelope terminating independently; no connected transmitter, fluid fill or response. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Throat line-end collar

Separate bored terminal collar without threads or selected fitting. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet element flange

Bored element flange with six invented true joint openings. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet companion flange

Independent companion flange with six matching locations; no standard class or selected facing. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet gasket location

Separate annular gasket location with a deliberate gap; no material, compression or leakage result. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet boundary spool

Independent short open boundary pipe; adjacent installation and required straight lengths are unspecified. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 1 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 1 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 1 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 1 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 2 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 2 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 2 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 2 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 3 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 3 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 3 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 3 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 4 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 4 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 4 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 4 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 5 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 5 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 5 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 5 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 6 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 6 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 6 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Inlet joint 6 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet element flange

Bored element flange with six invented true joint openings. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet companion flange

Independent companion flange with six matching locations; no standard class or selected facing. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet gasket location

Separate annular gasket location with a deliberate gap; no material, compression or leakage result. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet boundary spool

Independent short open boundary pipe; adjacent installation and required straight lengths are unspecified. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 1 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 1 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 1 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 1 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 2 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 2 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 2 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 2 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 3 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 3 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 3 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 3 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 4 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 4 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 4 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 4 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 5 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 5 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 5 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 5 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 6 smooth stud

Separate smooth stud marker; no thread, preload or load path. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 6 left washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 6 right washer

Separate washer with a real central opening. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Outlet joint 6 nut

Hexagonal nut envelope with a true bore; no thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream support shoe

Independent support-location block with deliberate separation from the passage; no saddle fit or load calculation. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream support foot

Separate foot envelope with two actual anchor-location bores. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 1 smooth anchor

Separate smooth anchor-location marker, with no embedment or foundation design. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 1 washer

Separate annular anchor washer. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 1 nut

Bored hexagonal anchor-nut envelope without thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 2 smooth anchor

Separate smooth anchor-location marker, with no embedment or foundation design. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 2 washer

Separate annular anchor washer. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Upstream foot joint 2 nut

Bored hexagonal anchor-nut envelope without thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream support shoe

Independent support-location block with deliberate separation from the passage; no saddle fit or load calculation. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream support foot

Separate foot envelope with two actual anchor-location bores. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 1 smooth anchor

Separate smooth anchor-location marker, with no embedment or foundation design. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 1 washer

Separate annular anchor washer. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 1 nut

Bored hexagonal anchor-nut envelope without thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 2 smooth anchor

Separate smooth anchor-location marker, with no embedment or foundation design. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 2 washer

Separate annular anchor washer. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Downstream foot joint 2 nut

Bored hexagonal anchor-nut envelope without thread engagement. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Illustrative direction shaft

Static arrow shaft for the invented upstream-to-throat-to-outlet reading direction. No fluid velocity or flow rate. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.

Illustrative direction head

Static annotation outside the passage; no live or simulated flow. Original static teaching geometry; no measured flow/pressure, calibration, coefficient, leak, material, rating or service qualification.