NPSH (Net Positive Suction Head) Calculator

📋 Sizing Parameters

Units: SI Metric (m, kPa, °C)

Reservoir Type: Open to Atmosphere ($P_{atm}$)

Reservoir Surface Pressure ($P_s$)

Liquid Elevation ($z$)

Suction Friction Loss ($h_f$)

Velocity Head Loss ($h_v$ - Optional)

Liquid Temperature ($T$)

Fluid

Vapor Pressure ($P_v$)

Fluid Density ($\rho$)

Required NPSH ($NPSH_R$)

Adjust Elevation ($z$): +2.5 m

📊 Sizing Results

NPSH Available vs Required meters

0.0 NPSH_R 20.0

NPSH Available (NPSHa) — m

Safety Margin — m

Safety Ratio — —

NPSH Check OK

NPSH available is safe and meets cavitation guidelines.

NPSH Sizing Equations:
• $NPSH_A = \frac{P_s - P_v}{\rho \cdot g} + z - h_f - h_v$ (Metric)
• $NPSH_A = \frac{144 \cdot (P_s - P_v)}{\rho} + z - h_f - h_v$ (Imperial)
• Margin = $NPSH_A - NPSH_R$

🔴 NPSH (Net Positive Suction Head) Calculator

📋 Sizing Parameters

📊 Sizing Results

NPSH Check OK