Diffusion Engineers Interview Questions and Answers

NPSH available stands for Net Positive Suction Head available, which is a measure of the absolute pressure at the suction port of a pump.

• NPSH available is the total suction head in feet absolute at the suction nozzle of the pump.

• It is important for ensuring that the pump does not cavitate, which can cause damage to the pump and decrease efficiency.

• NPSH available is calculated by subtracting the vapor pressure of the liquid from the total suction head.

• It is crucial to maintain...read more

NPSH is calculated by subtracting the vapor pressure of the liquid from the total head of the pump.

• NPSH = H - (Pv / rho * g)

• H is the total head of the pump

• Pv is the vapor pressure of the liquid

• rho is the density of the liquid

• g is the acceleration due to gravity

• Ensure all units are consistent (e.g. meters, Pascal, kg/m^3, m/s^2)

Types of PSV include conventional spring-loaded PSV, pilot-operated PSV, balanced bellows PSV, and rupture disc PSV.

• Conventional spring-loaded PSV

• Pilot-operated PSV

• Balanced bellows PSV

• Rupture disc PSV

Heat exchanger types include shell and tube, plate, finned tube, and double pipe.

• Shell and tube heat exchanger

• Plate heat exchanger

• Finned tube heat exchanger

• Double pipe heat exchanger

P&ID of Pump System shows the piping, equipment, instrumentation, and control interlocks of the system.

• Include pump symbol with arrows indicating flow direction

• Label all equipment such as pumps, valves, tanks, etc.

• Show instrumentation like pressure gauges, flow meters, etc.

• Indicate control interlocks and safety features

• Use standard symbols and colors as per industry guidelines