PlumbingIntermediate
Available Water Pressure
Estimate residual pressure after elevation, meter, backflow, piping, valve, and equipment losses.
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Plumbing Engineering
Domestic water, sanitary drainage, stormwater, fuel systems, pumps, water heating, pressure, pipe sizing, and commissioning calculations.
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Available calculation tools
62 reviewed tools are available in this collection.
PlumbingBeginner
Hot-Water Mixing
Calculate ideal hot- and cold-water flow fractions required to produce a selected mixed-water temperature.
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Fixture-Unit Summation
Sum user-entered fixture counts and fixture-unit values without embedding a code table or converting the total to probable demand.
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Water-Heater Recovery
Estimate steady water-heater recovery from input rate, thermal efficiency, and temperature rise.
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Mixed-Water Storage Yield
Estimate ideal deliverable mixed-water volume from stored hot water and selected hot, cold, and delivery temperatures.
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Recirculation Flow
Calculate steady recirculation flow required to carry a user-entered loop heat loss at an allowable temperature drop.
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Recirculation Heat Loss
Convert a documented linear pipe heat-loss rate and effective length into steady and annual heat loss.
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Hot-Water Delivery Time
Estimate ideal pipe displacement volume and delivery time from internal diameter, developed length, and fixture flow.
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Gravity Drain Slope
Calculate pipe fall and slope from upstream and downstream invert elevations and horizontal run.
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Manning Drain Capacity
Estimate full-flow circular-pipe discharge and velocity using the Manning equation.
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Roof Drainage Flow
Convert tributary roof area and user-entered rainfall intensity into runoff flow before code-based drain sizing.
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Rational Runoff
Estimate peak runoff from user-entered area, rainfall intensity, and runoff coefficient.
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Fuel-Gas Load and Flow
Sum user-entered appliance loads and convert diversified load to ideal gas volume flow using a user-entered heating value.
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Gas-Meter Capacity Margin
Compare user-entered meter capacity with diversified design flow using a visible capacity factor.
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Booster Pressure
Calculate preliminary booster pressure from supply pressure, required residual pressure, elevation, losses, and a visible user-entered margin.
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PRV Setpoint
Calculate a preliminary PRV setpoint for an upper outlet and the resulting lower static-pressure screen.
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Storage and Recovery Balance
Convert a peak mixed-water draw to stored-hot-water demand and subtract recovery available during the peak interval.
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Sewage-Ejector Duty
Assemble a preliminary sewage-ejector flow and head duty point from visible user-approved inputs.
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Sump-Basin Cycling
Estimate working drawdown volume, pump-on time, refill time, and starts per hour for a constant-area basin.
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Recirculation Temperature Retention
Evaluate measured return temperature relative to supply and cold-water temperatures and calculate loop heat loss at measured flow.
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Water-Heater Capacity Test
Calculate measured water-heating output, direct operating efficiency, and output relative to a user-entered schedule.
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Plumbing-Pump Field Test
Combine measured flow, suction/discharge pressure, gauge elevation, specific gravity, and electrical input into a pump performance screen.
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Water Loss Budget
Calculate the pressure allowance remaining for distributed pipe friction along a critical domestic-water path.
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Hazen–Williams Flow
Invert the Hazen–Williams relationship to estimate flow from diameter, length, C-factor, and available friction head.
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Pipe Flush Time
Calculate contained circular-pipe volume and ideal duration for a user-entered number of volume exchanges.
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Meter Loss Scaling
Scale a documented meter pressure-loss point to another flow using a visible user-entered exponent.
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Backflow Loss Margin
Compare a documented backflow-device loss with the pressure allowance assigned to that device.
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Thermal Expansion Volume
Calculate water-volume change from initial volume and user-entered initial and final densities.
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Tank Acceptance
Estimate ideal tank acceptance between initial and maximum gauge pressures using absolute-pressure gas relationships.
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Water-Hammer Surge
Apply the ideal Joukowsky relationship to a user-entered density, wave speed, and signed velocity change.
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PRV Reduction
Calculate pressure drop, percent reduction, and inlet-to-outlet ratio for a documented PRV condition.
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Draw Energy
Calculate ideal useful energy added to a documented hot-water draw volume.
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First-Period Delivery
Add usable hot-water storage and recovery over a user-entered rating period.
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Heater Standby Loss
Subtract useful delivered-water energy from measured input over a defined test boundary and duration.
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Tempering Valve Margin
Compare a design mixed-water flow with an effective user-derated tempering-valve capacity.
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Recirculation Pump Head
Calculate signed pump head from suction/discharge pressures, gauge elevation difference, and fluid specific gravity.
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Trap-Primer Demand
Calculate daily primer-water volume and water per design event from user-entered dose and schedule values.
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Pure-Water Autonomy
Calculate constant-demand operating time from usable storage, reserve fraction, and average demand.
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Cylinder-Bank Duration
Calculate ideal constant-demand duration from cylinder count, standard gas volume, and a user-entered usable fraction.
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Receiver Evacuation
Estimate ideal isothermal evacuation time for a lumped receiver at constant effective pump speed.
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Greywater Balance
Compare treated usable daily collection with nonpotable demand using a visible treatment-recovery factor.
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Interceptor Retention
Calculate ideal hydraulic retention time from operating volume, effective-volume fraction, and constant peak flow.
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Part-Full Manning Flow
Calculate part-full circular-pipe flow from depth ratio, diameter, slope, and Manning roughness.
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Drain Travel Time
Calculate ideal flow travel time from path length and user-entered mean velocity.
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Duplex Pump Drawdown
Compare working-volume drawdown time with the lead pump and with both pumps operating.
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Roof Drain Area
Invert the roof-runoff relationship to screen tributary area from documented drain flow capacity and rainfall.
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Rainfall Runoff Volume
Convert tributary area, storm depth, and runoff factor into a runoff volume.
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Storm Capacity Utilization
Compare design storm flow with a separately established screened capacity.
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Scupper Weir Flow
Apply a generic rectangular-weir form using a user-entered coefficient, clear width, and head.
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Detention Storage Balance
Calculate net storage change from average inflow, average outflow, and event duration.
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Storm Pump Drawdown
Calculate constant-flow drawdown time from stored volume, continuing inflow, and pump flow.
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Gas Equivalent Length
Sum straight length, two fitting groups, and a visible allowance without performing gas-pipe sizing.
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Gas Pressure Budget
Calculate gas-piping pressure-drop allowance after required downstream pressure and fixed losses.
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Combustion Air
Apply a visible user-entered air rate per heat input and design factor; no code rate is embedded.
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Air Receiver Duration
Estimate ideal receiver support time between two gauge pressures at a constant net standard demand.
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Air Leak Rate
Estimate ideal standard-air leak rate from isolated volume, gauge-pressure decay, atmosphere, and elapsed time.
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Air Pressure Ratio
Calculate inlet-to-outlet absolute pressure ratio and percent pressure reduction.
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Fuel-Oil Consumption
Calculate liquid fuel use from useful heat rate, conversion efficiency, and user-entered heating value.
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Day-Tank Runtime
Calculate constant-demand runtime from tank volume, usable fraction, reserve fraction, and fuel demand.
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Propane Consumption
Calculate liquid-propane use from useful heat rate, conversion efficiency, and user-entered heating value.
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Gas-Pipe Purge Time
Calculate straight-pipe contained volume and ideal time for user-entered purge volume exchanges and flow.
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Gas-Pipe Velocity
Calculate mean pipe velocity from actual volumetric flow at pipe conditions and actual internal diameter.
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Technical resources in development
The platform will add field guides, articles, videos, standards notes, templates, and professional workflow resources alongside the Free calculator library.
Explore the resource roadmap- Domestic water pressure
- Hot-water generation and mixing
- Sanitary and storm drainage
- Fuel-gas systems
- Plumbing commissioning