Cooling Water Transfer Line
Pump, pipe, and fittings — solved in your browser.

What's in the flowsheet

• An Inlet standing in for the supply tank — water at 25 °C, atmospheric pressure, 12.6 kg/s (~200 gpm).
• A Centrifugal Pump in pressure-increase mode (50 psi rise, 75 % efficiency).
• The connector between the pump and the valve is the pipe: 150 ft of 3" Sch 40 carbon steel, commercial-steel roughness (0.0457 mm), +30 ft elevation. Its Pipe tab also carries the non-valve fittings — square-edge entrance, four 90° long-radius elbows, and a pipe outlet.
• A standalone Gate Valve as a P&ID symbol, sized to the same 3" Sch 40 so its K-factor is consistent with the pipe.
• An Outlet for the discharge.

What to try first

1. Run the flowsheet as-is and note the pump shaft power and pipe ΔP.
2. Click the long connector → Pipe → Results. Reynolds number, velocity, friction factor, and pressure drop are all live.
3. Drop the pipe size from 3" to 2-1/2". Velocity jumps, Reynolds barely changes, but the pressure drop scales roughly as D ^-5. Classic.
4. Open the gate valve unit and switch it to Closed. The K-factor goes effectively infinite and the run fails on a blocked path — exactly the right behavior.
5. Set the elevation change to a negative number (gravity flow downhill). Required pump head drops.

How the pressure drop is computed

Friction factor uses the Serghides approximation to the Colebrook–White equation — accurate across the laminar, transitional, and turbulent regimes, and continuous through Re = 2300. The total pipe pressure drop is the sum of the Darcy–Weisbach friction term, the fitting K-factors (3-K method via the standard Crane-style tables), and the elevation head.

The standalone gate valve unit contributes its own K-factor — a separate ΔP step in the simulation — and the connector adds the friction, fittings, and elevation. Pump shaft power is computed from the volumetric flow, density, ΔP, and efficiency.

Everything runs in your browser. Nothing is uploaded; nothing leaves the page. Save the flowsheet to JSON and reload it later, or share it as a file alongside a spec sheet or a homework solution.

Why this matters

Hydraulic sizing is the calculation every plant and design engineer ends up doing in a spreadsheet they don’t fully trust. The textbook version is straightforward, but a real piping run mixes friction, fittings, elevation, valves, and a pump curve — and getting the units and the K-factor conventions consistent is where mistakes happen. Doing it as a flowsheet keeps everything in one place and makes the “what if I swap the pipe size?” question a single click instead of a spreadsheet rewrite.

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