Centrifugal pump head & shaft power
H = Δp/(ρg) + (v₂²−v₁²)/(2g) + Δz; P = ρgQH / η
Q 180 m³/h, Δp 3.0 bar, DN150 / DN100, Δz 0.4 m, η 78%
- Head
- 32.7 m
- Hydraulic power
- 16 kW
- Shaft power
- 20.5 kW
ISO 9906:2012
Free during public beta
Pipe pressure drop, pump head and shaft power, heat exchangers, cable voltage drop — put data tables, unit conversion, formula modules and flowsheets into one project and export a Word / PDF calculation report. Change one input and the whole flowsheet recalculates.
Free during public beta. Verify results against engineering codes; use “Report an issue” in the workspace for feedback.
Each figure is a machine you recognise, with a three-parameter control panel underneath: needles, handwheels, fluid columns and the readout are driven by one calculation model. Defaults are the worked examples from standards and textbooks.
Water / process design
ISO 9906:2012 · benchmark GC-IND-PUMP-001
Build this calculation in the workspace →Centrifugal pump test bench (ISO 9906): a motor drives an end-suction volute pump at constant speed through a coupling inside a windowed guard, both on a common baseplate with anchor bolts. The DN150 suction line with a pressure gauge draws from a sump; the DN100 discharge riser with a pressure gauge returns to the sump through an electromagnetic flowmeter and a gate valve. Turning the gate-valve handwheel sets the flow and moves the flowmeter bar; the discharge gauge reads the pressure rise; the wattmeter on the left reads shaft power P = ρgQH/η and the bar below it reads pump efficiency.
Piping / water / HVAC
Crane TP-410 · Swamee–Jain (1976) · benchmark GC-IND-DW-001
Build this calculation in the workspace →Pipe friction test section: water leaves a surge tank on the left, passes a control valve (handwheel) and an electromagnetic flowmeter into a steel pipe, runs to a U-bend at the right and back through a sight glass into the tank. Inlet and outlet taps each carry a 0–6 bar gauge: the inlet reads a fixed 4.0 bar, the outlet needle reads inlet minus the friction pressure drop (Darcy–Weisbach). Flow turns the handwheel and changes the tracer speed in the sight glass; the nameplate shows the nominal diameter DN and test length L, and a cursor on the front ruler marks L.
Chemical / pharma / energy
Incropera, Heat and Mass Transfer 6th ed., Ex. 11.1 · benchmark GC-IND-HX-LMTD-001
Build this calculation in the workspace →Hairpin counter-flow double-pipe heat exchanger: two outer legs joined by a U-bend stand on two saddles; hot oil (cooled to 60 °C) flows in the inner tube and cooling water in the annulus. Water enters the lower leg through a globe valve and a rotameter and leaves the upper leg, counter to the oil. Changing water flow turns the handwheel and moves the rotameter float; changing the water or oil inlet temperature moves that thermometer's column; the water-outlet thermometer follows the calculated outlet temperature.
Process flowsheets
Analytical mass balance · benchmark GC-IND-RXN-001
Build this calculation in the workspace →Reactor + separator with recycle: product from a jacketed stirred-tank reactor feeds a separation column; unreacted feed from the column bottom is pumped back to the reactor top, and a purge line with a handwheel valve branches off the recycle line. A two-digit counter on the instrument box replays the number of tear-stream iterations to convergence while the residual needle settles to zero.
Real clicks recorded in the workspace, using the built-in wastewater plant example project.
Darcy–Weisbach with the Swamee–Jain friction factor for turbulent flow and 64/Re for laminar flow. Drag the sliders.
ΔP = f · (L / D) · ρv² / 2 · Re = ρvD / μ · f = 0.25 / [log₁₀(ε / 3.7D + 5.74 / Re⁰·⁹)]²
Fluid: water at 20 °C (ρ 998.2 kg/m³, μ 1.0016 cP), commercial steel ε = 0.045 mm
Default inputs are industry benchmark GC-IND-DW-001: 29.5 kPa.
Save as a project and continue with pumps →Each example is a benchmark case in the project: inputs from standards or textbook examples, expected values derived independently, compared row by row.
H = Δp/(ρg) + (v₂²−v₁²)/(2g) + Δz; P = ρgQH / η
Q 180 m³/h, Δp 3.0 bar, DN150 / DN100, Δz 0.4 m, η 78%
ISO 9906:2012
NPSHa = (p₁ − p_v)/(ρg) + v₁²/(2g) + z₁
Water at 20 °C, vapour pressure per IAPWS-IF97
ISO 9906:2012 §3.2
Q = ṁc_pΔT; ΔT_lm = (ΔT₁ − ΔT₂) / ln(ΔT₁/ΔT₂)
Oil 0.1 kg/s 100→60 °C, water 0.2 kg/s in at 30 °C
Incropera, Heat and Mass Transfer 6th ed., Ex. 11.1
u = b(ρ₁L/S·cosφ + λL·sinφ)·I_B
100 A, 150 m, 35 mm² copper, cosφ 0.85, 230 V
IEC 60364-5-52 Annex G
50% single-pass conversion, 90% of unreacted feed recycled
Tear-stream iteration compared with the analytical solution
Analytical mass balance
ΔP = f·(L/D)·ρv²/2
50 m³/h, DN100, 100 m, ε 0.045 mm
Crane TP-410 / Swamee–Jain (1976)
Example values illustrate the method. Verify engineering results against applicable codes and have them approved by qualified personnel.
Every step stays in the same project: traceable data, reusable formulas, checkable results.
Import Excel / CSV and switch design cases; downstream modules recalculate.
Dimension checks and unit sets (SI / metric / English) — enter values in any unit.
100 m³/h
Build reusable modules with forms and Excel-style formulas, with checks.
Connect modules and streams; mixing, splitting and recycle convergence are handled.
Formulas, substituted values and conclusions, exported to Word / PDF / Excel.
One calculation engine behind the UI, the command line and the API.
Script batch calculations, report export and flowsheet rendering.
Create a personal access token in the account page and let agents call /api/peb/agent; commands ship with JSON Schema and work as LLM tools. See /llms.txt.
Files, version history and recycle bin; owner / editor / viewer roles and real-time co-editing.
$ peb run pump-chain.project.json
■ P-101 head H = 50 m
■ P-101 shaft power P = 18.16 kW
$ peb report water-treatment.project.json --format docx
✓ calculation-report.docxYes, during the public beta. Paid plans will be announced in the app in advance.
The engine is benchmarked against public standards and textbook examples (pumps, NPSH, heat transfer, pressure drop, cable voltage drop, recycles). Verify engineering results against applicable codes.
Four unit sets — SI, metric, metric-bar and English; units can be mixed and are converted by dimension.
Calculation reports to Word, PDF and Excel; data tables via Excel / CSV.
Public beta data is stored on cloud servers in Singapore and is never sent to third-party models. See the privacy policy.
Sign up and go straight to the workspace — three example projects (wastewater plant, pump chain, electrical & instrumentation) are ready to run.
Start free →