How To Calculate Discharge Pressure Of Pump

Discharge Pressure Formula:

\[ P_d = \rho g H + P_s \]

Fluid Density (ρ):

kg/m³

Gravity (g):

m/s²

Head (H):

Suction Pressure (P_s):

Discharge Pressure (P_d):

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1. What Is Discharge Pressure Of Pump?

Discharge pressure is the total pressure at the outlet of a pump, calculated as the sum of the pressure head developed by the pump and the suction pressure. It represents the energy imparted to the fluid by the pump.

2. How Does The Calculator Work?

The calculator uses the discharge pressure formula:

\[ P_d = \rho g H + P_s \]

Where:

\( P_d \) — Discharge pressure (Pa)
\( \rho \) — Fluid density (kg/m³)
\( g \) — Gravitational acceleration (m/s²)
\( H \) — Pump head (m)
\( P_s \) — Suction pressure (Pa)

Explanation: The formula calculates the total pressure at the pump discharge by adding the pressure developed due to the pump head (ρgH) to the existing suction pressure (P_s).

3. Importance Of Discharge Pressure Calculation

Details: Accurate discharge pressure calculation is crucial for pump selection, system design, ensuring proper flow rates, preventing cavitation, and maintaining system efficiency in various industrial and domestic applications.

4. Using The Calculator

Tips: Enter fluid density in kg/m³, gravitational acceleration in m/s² (default is 9.81 m/s²), pump head in meters, and suction pressure in Pascals. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between discharge pressure and pump head?
A: Pump head is the energy per unit weight of fluid, measured in meters, while discharge pressure is the total pressure at the pump outlet, measured in Pascals.

Q2: Why is suction pressure included in the calculation?
A: Suction pressure represents the pressure already present at the pump inlet, which contributes to the total discharge pressure output.

Q3: What are typical values for fluid density?
A: Water at 20°C is approximately 998 kg/m³, while other fluids vary (oil: 800-900 kg/m³, seawater: 1025 kg/m³).

Q4: When is this calculation most important?
A: Critical for pump sizing, system design, pressure vessel requirements, and ensuring pumps can overcome system resistance.

Q5: Are there limitations to this formula?
A: This is the basic formula; for precise calculations, factors like friction losses, elevation changes, and pump efficiency should be considered.