How to you calculate suction pressure and discharge pressure and NPSH in pump ?

Question

Accepted Answer

Suction pressure, discharge pressure, and NPSH in pumps are calculated using specific formulas and measurements.

Suction pressure is calculated by measuring the pressure at the pump inlet.
Discharge pressure is calculated by measuring the pressure at the pump outlet.
NPSH (Net Positive Suction Head) is calculated by subtracting the vapor pressure of the fluid from the total suction head.
Formulas: NPSH = (P_atm - P_vap) / (rho * g) + h_suction, where P_atm is atmospheric pressure, P_vap is vapor pressure, rho is fluid density, g is acceleration due to gravity, and h_suction is suction head.
Example: If atmospheric pressure is 101.3 kPa, vapor pressure is 2 kPa, fluid density is 1000 kg/m^3, acceleration due to gravity is 9.81 m/s^2, and suction head is 5 m, NPSH = (101.3 - 2) / (1000 * 9.81) + 5.

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