HPCL-Mittal Energy Limited Interview Questions, Process, and Tips

PID control is a feedback control mechanism used in automation systems to regulate a process variable.

• PID stands for Proportional-Integral-Derivative.

• It continuously calculates an error value by comparing the desired setpoint with the actual process variable.

• The controller then adjusts the control output based on the error value and the proportional, integral, and derivative gains.

• Proportional control provides an outpu...read more

PID control is necessary to maintain a desired setpoint and compensate for disturbances in a system.

• PID control helps maintain stability and accuracy in a system

• It adjusts the output based on the difference between the setpoint and actual value

• It can compensate for disturbances such as changes in load or input

• Examples include temperature control in HVAC systems and speed control in motors

DV6200 is calibrated using a multi-point calibration process.

• Perform a zero calibration by disconnecting the sensor and setting the output to zero.

• Perform a span calibration by applying a known input and adjusting the output to match.

• Perform a linearity calibration by applying multiple inputs and verifying the output matches the expected values.

• Record all calibration data and ensure it is within acceptable tolerances.

• P...read more

If PT of extruder package required to change, I will follow the standard procedure for changing PT.

• Refer to the manufacturer's manual for the correct procedure

• Ensure that the system is depressurized and isolated before starting the work

• Use appropriate tools and equipment to remove the old PT and install the new one

• Perform leak testing and calibration after installation

• Update the documentation and inform the relevant pe

At least 2 DI and 1 DO loop are needed to control a HT motor.

• DI loops are used for monitoring the motor's status and feedback signals.

• DO loops are used for controlling the motor's speed and direction.

• The number of loops required may vary depending on the specific motor and control system.

• Additional loops may be needed for safety interlocks and alarms.

Confined space refers to an area with limited access and ventilation, posing potential hazards to workers.

• Examples include tanks, silos, sewers, and tunnels.

• Workers entering confined spaces must follow strict safety protocols.

• Hazards in confined spaces include lack of oxygen, toxic gases, and fire/explosion risks.

• Proper training and equipment are necessary for working in confined spaces.

Follow OSHA guidelines for confined space entry and ensure proper ventilation, communication, and rescue procedures.

• Conduct a thorough hazard assessment before entering the confined space

• Ensure proper ventilation and air quality testing

• Use appropriate personal protective equipment (PPE)

• Establish communication procedures and have a standby person outside the confined space

• Have a rescue plan in place and conduct regular ...read more

There are various types of flow measuring equipment available for measuring process flow.

• Magnetic flow meters

• Ultrasonic flow meters

• Vortex flow meters

• Coriolis flow meters

• Differential pressure flow meters

• Positive displacement flow meters

• Thermal flow meters

The ideal gas equation relates the pressure, volume, and temperature of an ideal gas.

• The ideal gas equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature.

• It describes the behavior of an ideal gas under various conditions.

• The equation can be used to calculate any one of the variables if the others are known.

• For example, if th...read more

N in Ideal gas equation represents the number of moles of gas.

• N is the number of moles of gas in the system

• It is a measure of the amount of gas present

• N is directly proportional to the number of gas particles

• Ideal gas equation is PV = nRT, where n is the number of moles of gas

• N is usually measured in moles

I can handle multiple types of HMI including SCADA, DCS, and PLC.

• I am proficient in SCADA (Supervisory Control and Data Acquisition) systems.

• I have experience with DCS (Distributed Control System) HMIs.

• I am familiar with PLC (Programmable Logic Controller) HMIs.

• I can work with various HMI software such as Wonderware, Ignition, and FactoryTalk.

• I am capable of configuring and troubleshooting HMI systems.

• I stay updated wi

TBT stands for 'Tool Box Talk'.

• TBT is a safety meeting held before starting a job or task.

• It is a way to discuss potential hazards and safety procedures.

• TBTs are usually short and focused on a specific topic.

• They are important for promoting a safety culture in the workplace.

• Examples of TBT topics include working at heights, electrical safety, and PPE use.

To solve close tank level fluctuation, I would approach by identifying the root cause and implementing appropriate corrective measures.

• Check for any leaks in the tank or piping system

• Ensure proper calibration of level sensors

• Verify the control system settings and adjust if necessary

• Consider installing additional instrumentation such as a surge tank or pressure relief valve

• Perform regular maintenance and inspections to

There are three types of orifice plates used to measure DP of a process flow line.

• Concentric

• Eccentric

• Segmental

Mass flow is measured based on the principle of conservation of mass and the relationship between flow rate, velocity, and cross-sectional area.

• Mass flow can be measured using various techniques such as Coriolis flow meters, thermal mass flow meters, and differential pressure flow meters.

• The principle of conservation of mass states that mass cannot be created or destroyed, only transferred or converted.

• The relationship...read more

A vortex flow meter measures fluid flow by detecting the frequency of vortices shed by a bluff body in the flow stream.

• A bluff body is placed in the flow stream to create vortices.

• The frequency of vortices is proportional to the flow rate.

• The meter measures the frequency and calculates the flow rate.

• Vortex flow meters are commonly used in steam, gas, and liquid applications.

Bernoulli's theorem states that as the speed of a fluid increases, its pressure decreases.

• Describes the relationship between fluid speed and pressure

• Used in fluid dynamics and aerodynamics

• Can be applied to various scenarios such as air flow over an airplane wing or water flow through a pipe

• Formula: P + 1/2pv^2 + pgh = constant (where P is pressure, p is density, v is velocity, g is acceleration due to gravity, and h is