Also in: Disaster Response and Recovery
Pump Total Dynamic Head (TDH)
Total dynamic head from static lift, static discharge, and Hazen-Williams suction / discharge / fittings friction.
Example
You enter
- Flow rate (GPM) 100
- Pipe internal diameter (in) 4.026
- Hazen-Williams C (150 PVC / 130 steel) 150
- Static suction lift (ft; negative if flooded) 10
- Static discharge head (ft) 50
- Suction pipe length (ft) 20
- Discharge pipe length (ft) 200
- Fittings equivalent length (ft) 30
You get
- Static head (ft) 60
- Total dynamic head (ft) 61.4
- Pipe velocity (ft/s) 2.52
Checked against published worked examples from: Crane / Hazen-Williams.
Details, formula, and sources
ScopeWith a pump-curve operating point.
Formula or tableTDH = (static_discharge_head + static_suction_lift) + suction_friction + discharge_friction + fittings_friction. Friction (feet of head) = Hazen-Williams h_f = 10.44*Q^1.852 / (C^1.852 * d^4.87) * L. Pipe velocity v (ft/s) = 0.4085 * GPM / d^2.
Source and editionHazen-Williams (1905, public domain); Crane Technical Paper No. 410 (fittings equivalent length).
Free accessFree at flowoffluids.com for Crane TP-410 excerpts.
What governsEstimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
API field namesflow_gpm, internal_diameter_in, hw_c, static_suction_lift_ft, static_discharge_head_ft, suction_length_ft, discharge_length_ft, fittings_equiv_length_ft, static_head_ft, tdh_ft, velocity_fps
- Hazen-Williams C 150 PVC / 130 new steel / 100 old steel; the user enters the valueCrane TP-410
- Fittings entered as an equivalent pipe length (ft) per TP-410; the tile bundles no fitting tableCrane TP-410
- Operating point the manufacturer pump curve governs the actual head at the duty flowpump manufacturer