TryBuildCalc

Water Pump Sizing Verification Checklist

Essential Checklist+

Complete these critical checks before approving the work or proceeding to the next construction stage.

✓13 Inspection Points
✓6 Verification Categories
✓Scenario & Flow Rate+
  • Pump Scenario selected (Booster vs Well/Transfer) matches the actual water source — an existing pressurized supply vs. an unpressurized well/cistern/tank.
  • If using Add Fixtures, every fixture expected to draw water during peak simultaneous demand is included, matching the same fixture list this site's Pipe Sizing by Fixture Units calculator would use.
✓Total Dynamic Head Inputs+
  • Elevation input reflects the correct span for the selected scenario — boost-point-to-highest-fixture for Booster, full source-to-highest-fixture lift for Well/Transfer.
  • Pipe run length is the full developed length from the pump to the highest/most remote fixture, including vertical runs, not just the horizontal footprint distance.
  • For Booster scenarios, available incoming pressure was measured at the actual boost-point location, not assumed from a general impression of local water pressure.
✓Pump Power & Selection+
  • Required GPM and TDH were used together to check a specific candidate pump's actual published pump curve, not just its horsepower rating alone.
  • A feasibility warning (demand exceeding every standard motor class) was resolved via multiple pumps, a commercial/fire-pump design, or zoned service — not worked around with an undersized single pump.
  • An over-pressure warning (discharge exceeding 80 psi) was resolved with a pressure-reducing valve on lower floors/fixtures near the pump, not ignored.
✓Pressure Tank (if included)+
  • For Check a Tank, calculated drawdown was checked against the selected pump's minimum recommended run time to avoid short-cycling.
✓Suction Side, Electrical & Installation (Not Computed Here)+
  • Suction-side pipe sizing and NPSH (net positive suction head) were checked separately — undersized or overly long suction piping can starve a pump regardless of discharge-side sizing.
  • Pump motor voltage, phase, amperage, and breaker size were confirmed with the pump manufacturer's data and a licensed electrician, not assumed.
  • Local permit, backflow-prevention, and cross-connection-control requirements for pump installation were confirmed and followed.
✓Final Check+
  • Purchased pump's published pump curve confirms it meets or exceeds the calculated GPM at the calculated TDH, not just a matching horsepower label.
Full QC Checklist+

Verify pump scenario, flow rate demand, Total Dynamic Head inputs, motor sizing, and pressure tank drawdown.

✓37 Inspection Points
✓7 Verification Categories
✓Scenario & Flow Rate+
  • Pump Scenario selected (Booster vs Well/Transfer) matches the actual water source — an existing pressurized supply vs. an unpressurized well/cistern/tank.
  • Flow-rate input mode (Add Fixtures vs Enter Directly) matches how the demand figure was actually derived, not left at a default.
  • If using Add Fixtures, every fixture expected to draw water during peak simultaneous demand is included, matching the same fixture list this site's Pipe Sizing by Fixture Units calculator would use.
  • If a direct flow rate was entered, it was cross-checked against an actual fixture tally or a measured/known peak flow, not guessed.
  • Building/occupancy type and system type (flush-tank vs flushometer) match the actual building, since they change the WSFU-to-GPM demand curve used.
✓Total Dynamic Head Inputs+
  • Elevation input reflects the correct span for the selected scenario — boost-point-to-highest-fixture for Booster, full source-to-highest-fixture lift for Well/Transfer.
  • Pipe material and nominal size match what's actually installed or planned, not left at a default that doesn't reflect the real pipe run.
  • Pipe run length is the full developed length from the pump to the highest/most remote fixture, including vertical runs, not just the horizontal footprint distance.
  • Required residual pressure at the far fixture reflects an actual design target (20-30+ psi for comfort, not just the 8-15 psi bare code minimum) appropriate for the fixtures served.
  • For Booster scenarios, available incoming pressure was measured at the actual boost-point location, not assumed from a general impression of local water pressure.
  • A "pump not needed" result was double-checked against the measured incoming pressure figure before concluding no booster is required.
✓Pump Power & Selection+
  • Pump efficiency reflects a real candidate pump's published efficiency at this duty point where known, rather than the generic 65% default.
  • Required GPM and TDH were used together to check a specific candidate pump's actual published pump curve, not just its horsepower rating alone.
  • The motor-size class recommendation (comfortable/borderline/oversized) was reviewed, and a "borderline" result was checked against the next size up.
  • A feasibility warning (demand exceeding every standard motor class) was resolved via multiple pumps, a commercial/fire-pump design, or zoned service — not worked around with an undersized single pump.
  • Pump configuration guidance (single/duplex/triplex) was reviewed against actual redundancy and maintenance needs, not just capacity.
  • An over-pressure warning (discharge exceeding 80 psi) was resolved with a pressure-reducing valve on lower floors/fixtures near the pump, not ignored.
✓Pressure Tank (if included)+
  • Tank Sizing Mode (Check a Tank vs Size a Tank) matches what's actually needed — sizing a new tank vs. verifying one already chosen.
  • Tank precharge pressure was verified with a tire-type pressure gauge at the tank (with the tank drained of water) rather than assumed from the factory sticker alone, since precharge drifts over time.
  • Cut-in and cut-out pressure switch settings match what's actually installed or planned, not generic 30/50 defaults if a different setting is intended.
  • For Check a Tank, calculated drawdown was checked against the selected pump's minimum recommended run time to avoid short-cycling.
  • For Size a Tank, the target run time reflects the selected pump's actual minimum recommended run time, not an arbitrary guess.
  • If drawdown is inadequate (or the required tank size seems impractically large), a larger tank, a wider cut-in/cut-out differential, or a smaller-flow pump was considered rather than accepting frequent short-cycling.
  • The nearest standard tank size was confirmed against the actual chosen brand's real lineup, not assumed to be exactly available.
✓Operating Cost (if included)+
  • Estimated daily run time reflects an actual known or measured value (a controller/timer log where available), not a guess presented as precise.
  • Electricity rate matches the actual local utility rate, not left at the ~17 cents/kWh US national-average default if a different regional rate applies.
  • Motor efficiency matches the selected/shortlisted motor's actual nameplate rating where known, rather than the generic 85% default, especially for a motor-size class at either end of the standard range.
  • Operating cost figures were treated as a planning estimate for comparing options, not a guaranteed utility bill figure.
✓Suction Side, Electrical & Installation (Not Computed Here)+
  • Suction-side pipe sizing and NPSH (net positive suction head) were checked separately — undersized or overly long suction piping can starve a pump regardless of discharge-side sizing.
  • Pump motor voltage, phase, amperage, and breaker size were confirmed with the pump manufacturer's data and a licensed electrician, not assumed.
  • Control scheme (constant-speed vs VFD, lead-lag alternation logic for duplex/triplex setups) was designed separately by a qualified professional.
  • Physical installation space, priming/flooded-suction requirements, and freeze protection (for outdoor or unconditioned locations) were confirmed.
  • Local permit, backflow-prevention, and cross-connection-control requirements for pump installation were confirmed and followed.
✓Final Check+
  • Purchased pump's published pump curve confirms it meets or exceeds the calculated GPM at the calculated TDH, not just a matching horsepower label.
  • A real-world peak-demand test (running the busiest expected fixture combination) was performed after installation to confirm adequate pressure and flow at the far fixture.
  • Final sizing figures and the installed pump/tank model are documented for future reference or troubleshooting.
  • Any deviation from this calculator's recommendation (a specific engineer's differing design, oversizing for future expansion) is documented with its rationale.
Inspection Notes+
Use the latest approved drawings, specifications, and site measurements.
Complete all critical checks before proceeding to the next work stage.
Record deviations and confirm rectification where required.

Related Calculators & Guides

Water Pump Sizing CalculatorOpen the related calculator and verify the current project inputs.

FAQ

Use it after collecting the project inputs and again before approving or closing the relevant work stage.
No. It supports verification but does not replace approved drawings, specifications, codes, manufacturer requirements, or professional inspection.