This simulator compares a pump feeding an adjustable globe control valve against a separate, speed-reduced reference case that delivers exactly the same flow through a fully open valve — making the hydraulic energy cost of throttling directly visible. Adjust pump speed, valve opening, valve Kv, static lift, pipe resistance and shared pump efficiency, and watch the actual and reference duties, energy columns and calculated power difference update together.
• A real-time 3D scene of the duty pump and motor, the magnified globe-valve plug and seat with visible stem travel, the demand/positioner mechanism, the pipe-resistance and elevated-load section, a separate open-valve speed-controlled reference case and an energy-accounting loss column, with home view, focus-selected-part, show-full-enclosure, exploded view, auto-rotate, expand and show/hide labels controls. • An Equipment laboratory tab with a labeled parts index (pump, trim, positioner, load, reference, loss columns, same-flow comparison recorder) and click-to-inspect component callouts. • Six experiment controls: actual pump speed (900–2,400 rpm), actual valve opening (0–100%), full-open valve Kv (30–120 m³/h at 1 bar), static system lift (0–25 m), pipe resistance coefficient (0.002–0.03 m/(m³/h)²) and shared illustrative pump efficiency (50–85%). • Playback controls: pause/resume, advance 0.1 s, advance 1 s, and four playback speeds (10× slow motion, real time, 10× faster, 1 minute per second), plus start/stop time, throttle-to-25% and open-valve-fully preset actions. • A Curves & measurements tab with two live charts (actual vs. reference shaft power, and valve/pipe/pump head breakdown), the governing equations (Kv relation, valve and pump head equations, shaft power, reference-speed solve) and snapshot measurement readouts. • An Experiments tab with four guided fixtures (moderate throttling, wide-open actual valve, strong throttling, closed valve) and a Model verification bench that runs independent deterministic checks against a fresh model without disturbing your live experiment, plus a timestamped event log and a copyable trial report. • A Learn & assess tab with guided lessons, a knowledge-check quiz with reset, and a written model-scope statement with a technical-background reference link.
A control valve regulates flow by dissipating mechanical energy as head loss across its restriction — it does not reduce the static lift or pipe friction the system must still overcome. In the simulator, the actual pump runs at a fixed speed and drives flow through the pipe, the static lift and the partially closed valve; the valve's share of that head is pure throttling loss.
The simulator also solves an independent reference case: the same delivered flow, but with the valve fully open (maximum Kv) and pump speed reduced just enough to meet the now-lower head requirement. Comparing the actual shaft power against this reference shaft power reveals the modeled energy penalty of throttling versus speed control for an equal-service duty.
The energy-accounting columns separate the actual shaft power, the hydraulic power dissipated at the valve, and the alternative reference shaft power, so you can see where energy goes rather than just a single number. Because both cases share the same constant illustrative pump efficiency, the calculated saving isolates the effect of throttling versus speed reduction — a real installation's actual saving also depends on motor and variable-frequency-drive efficiency curves, which this model does not include.
This is a steady, incompressible-water model using a synthetic quadratic pump curve, an ideal linear valve Kv relationship and a shared constant efficiency. It excludes cavitation, valve noise, actuator lag, stiction, motor/VFD efficiency maps and any minimum-speed restriction. The reference case is an independent equal-flow design calculation, not a second pump running in parallel on the same station.
Comparing power at different delivered flows would not be an equal-service comparison — a lower power at a lower flow tells you nothing about efficiency. The simulator's reference case is solved to deliver exactly the same flow as the actual throttled case, so the calculated shaft-power difference isolates the cost of throttling itself.
It is dissipated as heat and turbulence in the fluid and valve trim — mechanical energy that cannot be recovered downstream. The simulator accounts for this explicitly as hydraulic power loss at the valve, separate from the pipe and static-lift head the pump must still supply.
It demonstrates the modeled energy penalty for one operating point under simplified assumptions — a synthetic pump curve, ideal valve Kv, and equal constant efficiency for both cases. It excludes motor and VFD efficiency curves, minimum practical speed limits, and other real-world factors, so it should not be read as a universal economic conclusion.
At zero opening there is no delivered flow and no useful hydraulic power, but the model still shows a representative no-flow shaft loss — reflecting that a running pump against a closed valve is not free, even though it is doing no useful work.