Larsen & Toubro Limited Process Engineer Interview Questions, Process, and Tips

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

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 li...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)

A two-phase system P&ID shows the process flow of a system with two distinct phases.

• Identify the two phases involved in the system (e.g. liquid-gas, solid-liquid).

• Use different symbols to represent each phase on the P&ID.

• Show the flow direction and connections between components in the system.

• Include labels and legends to explain the components and their functions.

• Ensure clarity and consistency in the representation of

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