Hydraulic Profile & Pumping Calculator

Screen a representative MBR transfer, permeate, recycle, or sludge-pumping line for pipe friction, fitting loss, total dynamic head (TDH), preliminary electrical pump power, and annual energy. The calculator uses the Hazen–Williams relation for clean or treated-water screening; final pump selection requires the manufacturer curve, NPSH review, transient assessment, and the actual pipe network.

Use the flow while the pump is running. Average daily volume and pump run-hours determine the average pumping flow. Peak factor is applied to that operating flow for the peak TDH and preliminary motor screen.

Hydraulic inputs Enter one representative line and discharge condition for an early design screen.

Flow and operation

Average Daily Volume

m³/day pumped

Peak Pumping Factor

peak flow ÷ average operating flow

Pump Run Time

hours/day at average duty

Operating Days

days/year

Hydraulic profile and pipe

Static Lift

m from suction liquid level to discharge level

Required Discharge Pressure Head

mH₂O at discharge, if required

Equivalent Straight Pipe Length

m; exclude fittings represented by K

Pipe Internal Diameter

mm internal diameter

Hazen–Williams C

screening roughness coefficient

Total Fitting Loss Coefficient, ΣK

sum of valves, bends, entries, exits

Pump and motor assumptions

Overall Electrical-to-Liquid Efficiency

percent; pump × motor × drive

Motor Selection Margin

percent above peak electrical input

Hydraulic and pumping results Average case is used for annual energy; peak case is used for preliminary duty and motor screening.

Governing equations

The calculator applies Hazen–Williams pipe friction for a preliminary water-service screen, then adds static lift, local/fitting losses, and the required residual-pressure head.

v = Q ÷ A; A = πD² ÷ 4

h_f = 10.67 × L × Q^1.852 ÷ (C^1.852 × D^4.87)

h_minor = ΣK × v² ÷ (2g)

TDH = static lift + h_f + h_minor + H_residual

P_electrical = ρgQ × TDH ÷ η_{electrical-to-liquid}

The Hazen–Williams equation is an empirical water-flow relation. It is not a substitute for Darcy–Weisbach analysis where viscosity, temperature, non-water fluids, or detailed pipe roughness materially govern the design.

Design limits

This screen does not calculate NPSH available, pump curve intersection, minimum submergence, surge, water hammer, solids derating, or standby capacity. Confirm these items during detailed design.

Typical Hazen–Williams C Values

Use the installed pipe material, lining condition, age, and project standard. Lower values produce more conservative friction-loss results.

Pipe material / condition	Typical C
PVC / CPVC, new	150
HDPE / polyethylene	140–150
FRP / fiberglass	150
Ductile iron, cement-lined	120–140
Cast iron, new unlined	130
Cast iron, aged unlined	75–113
Steel, new unlined	140–150
Concrete or concrete-lined	120–140

Typical screening values compiled from Bentley HAMMER and Engineering ToolBox. Confirm project criteria before detailed design.

Typical Fitting Loss Coefficients, K

Enter the sum of applicable coefficients, ΣK. Values are illustrative fully-open screening values; actual geometry and manufacturer data govern.

Fitting / component	Typical K
Long-radius 90° elbow	0.2
Regular 90° elbow	0.3
45° elbow	0.2–0.4
Tee, straight-through flow	0.2–0.9
Tee, branch flow	1.0–2.0
Gate valve, fully open	0.15
Ball valve, fully open	0.05
Swing check valve	2.0
Globe valve, fully open	10
Diaphragm valve, open	2.3
Water meter	7

Values based on Engineering ToolBox’s minor-loss table. Use equipment-specific data when available.