ExxonMobil Associate Engineer Interview Questions and Answers

Critical radius of insulation is the thickness of insulation at which heat loss through the insulation is minimum.

• It is the point where the heat transfer rate is at its minimum.

• It is important in designing insulation systems.

• It depends on the thermal conductivity of the insulation material and the temperature difference across the insulation.

• If the insulation thickness is less than the critical radius, the heat loss wi...read more

Points on a stress-strain diagram represent specific stages of material deformation.

• The elastic limit is the point where deformation is reversible.

• The yield point is where plastic deformation begins.

• Ultimate strength is the maximum stress a material can withstand.

• Fracture point is where the material breaks.

• The modulus of elasticity is the slope of the linear portion of the curve.

• Each point on the diagram represents a s

Safety refers to the condition of being protected from harm, danger, or injury.

• Safety involves taking measures to prevent accidents and injuries

• It includes following rules and regulations to ensure a safe environment

• Safety can be achieved through proper training and education

• Examples of safety measures include wearing protective gear, using safety equipment, and practicing safe behaviors

• Safety is important in all indus...read more

LEL stands for Lower Explosive Limit and is the minimum concentration of a gas or vapor in air that can ignite.

• LEL is a safety term used in industries dealing with flammable gases and liquids.

• It is expressed as a percentage of the gas or vapor in air.

• If the concentration of the gas or vapor is below the LEL, it is too lean to ignite.

• If the concentration is above the LEL, it is too rich and can ignite.

• For example, the L...read more

JSA/JHA stands for Job Safety Analysis/Job Hazard Analysis. It is a process of identifying potential hazards and risks in a job or task.

• JSA/JHA is a systematic approach to identify and mitigate potential hazards in a job or task

• It involves breaking down a job or task into steps and analyzing each step for potential hazards

• The analysis includes identifying the hazards, assessing the risks, and implementing controls to m...read more

HSE plays a crucial role in ensuring the safety and well-being of employees and the environment.

• HSE stands for Health, Safety, and Environment.

• It involves identifying and assessing potential hazards and implementing measures to control or eliminate them.

• HSE also includes training employees on safety procedures and emergency response plans.

• Examples of HSE measures include wearing personal protective equipment, conductin...read more

Hchem is not a known term or acronym in the engineering field.

• Hchem is not a commonly used term in engineering

• It is possible that the interviewer misspoke or meant to ask a different question

• Without more context, it is difficult to provide a more specific answer

Hazop is a structured and systematic technique used to identify potential hazards and operability problems in industrial processes.

• Hazop stands for Hazard and Operability Study

• It involves a team of experts analyzing a process to identify potential hazards and operability issues

• Hazop is commonly used in the chemical, oil and gas, and pharmaceutical industries

• The process involves breaking down the process into smaller pa...read more

Confined space refers to an area that is enclosed and has limited access and ventilation.

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

• Workers entering confined spaces must follow safety protocols and use specialized equipment.

• Hazards in confined spaces include lack of oxygen, toxic gases, and physical obstructions.

• Proper training and communication are crucial for working in confined spaces.

Work at height refers to any task performed at a height where a person could fall and injure themselves.

• Work at height involves working on ladders, scaffolding, roofs, or any other elevated surface

• It is important to use appropriate safety equipment such as harnesses, guardrails, and safety nets

• Workers should be trained on how to safely work at height and how to properly use safety equipment

• Examples of work at height in...read more

Confined spaces pose a significant hazard due to limited entry and exit points, poor ventilation, and potential for hazardous substances.

• Limited entry and exit points can make it difficult to escape in case of an emergency

• Poor ventilation can lead to a buildup of toxic gases or lack of oxygen

• Potential for hazardous substances such as chemicals, fumes, or dust

• Examples include tanks, silos, sewers, and tunnels

• Proper trai...read more

Precautions to be taken while working in confined spaces

• Proper ventilation and air quality testing

• Use of personal protective equipment

• Proper lighting and communication equipment

• Training and certification for workers

• Emergency rescue plan in place

LEL&UEL stands for Lower Explosive Limit and Upper Explosive Limit respectively. They are the minimum and maximum concentrations of a flammable gas or vapor in air that can ignite.

• LEL is the lowest concentration of a gas or vapor that can ignite

• UEL is the highest concentration of a gas or vapor that can ignite

• Concentrations between LEL and UEL are considered flammable

• LEL and UEL vary depending on the gas or vapor

• LEL an...read more

Fire is a chemical reaction that releases heat, light, and various gases.

• Fire is a rapid oxidation process that occurs when fuel (such as wood, paper, or gasoline) combines with oxygen in the presence of heat or a spark.

• It releases heat, light, and various gases such as carbon dioxide, water vapor, and nitrogen oxides.

• Fire can be beneficial (such as for cooking or heating) or destructive (such as in wildfires or house ...read more

There are four types of fire: Class A, Class B, Class C, and Class D.

• Class A fires involve ordinary combustibles such as wood, paper, or cloth.

• Class B fires involve flammable liquids or gases such as gasoline, oil, or propane.

• Class C fires involve electrical equipment such as appliances, wiring, or circuit breakers.

• Class D fires involve combustible metals such as magnesium, titanium, or sodium.

There are different types of fire extinguishers for different types of fires.

• Water extinguishers for Class A fires (wood, paper, cloth, etc.)

• CO2 extinguishers for Class B and C fires (flammable liquids and electrical fires)

• Dry chemical extinguishers for Class A, B, and C fires

• Foam extinguishers for Class A and B fires

• Wet chemical extinguishers for Class K fires (cooking oils and fats)

Modes of heat transfer include conduction, convection, and radiation.

• Conduction is the transfer of heat through a material without any movement of the material itself.

• Convection is the transfer of heat through the movement of fluids, such as air or water.

• Radiation is the transfer of heat through electromagnetic waves, such as from the sun or a fire.

Preventing fire requires proper handling of flammable materials and regular maintenance of electrical equipment.

• Store flammable materials in designated areas away from heat sources

• Regularly inspect and maintain electrical equipment

• Install smoke detectors and fire extinguishers in appropriate locations

• Train employees on fire safety procedures and evacuation plans

MSDS stands for Material Safety Data Sheet.

• MSDS provides information about hazardous chemicals and substances.

• It includes information about the physical and chemical properties of the substance, health hazards, precautions for safe handling and use, and emergency procedures.

• MSDS is required by law for all hazardous chemicals and substances used in the workplace.

• It is important to read and understand the MSDS before usi...read more

Firefighting involves identifying and extinguishing fires to prevent damage and loss of life.

• Assess the situation and determine the type and size of fire

• Use appropriate firefighting equipment such as fire extinguishers, hoses, and pumps

• Follow safety protocols and wear protective gear

• Coordinate with other firefighters and emergency responders

• Evacuate people from the affected area

• Monitor the situation and ensure the fire

Prevent accidents by identifying potential hazards and implementing safety measures.

• Conduct regular safety audits and risk assessments

• Provide proper training and education to employees

• Implement safety protocols and procedures

• Use appropriate safety equipment and gear

• Encourage a culture of safety and accountability

• Regularly review and update safety policies and procedures

To investigate an accident, follow a systematic approach involving data collection, analysis, and identification of root causes.

• Gather all available information about the accident, including eyewitness accounts, photographs, and any relevant documents or records.

• Conduct interviews with individuals involved in the accident to gather their perspectives and insights.

• Examine the accident scene for physical evidence, such a...read more

H2S is a colorless, flammable, and toxic gas with a strong odor of rotten eggs.

• H2S is commonly known as hydrogen sulfide.

• It is produced naturally by the breakdown of organic matter and is found in natural gas, crude oil, and volcanic gases.

• It is highly toxic and can cause respiratory failure, loss of consciousness, and even death.

• H2S is used in various industries such as oil and gas, mining, and pulp and paper.

• It is al...read more

H2S is a colorless, flammable, and toxic gas with a strong odor of rotten eggs.

• H2S is highly flammable and can ignite easily

• It is toxic and can cause respiratory failure

• It has a distinctive odor of rotten eggs

• H2S is used in the production of sulfuric acid and in the petroleum industry

Permissible exposure limits (PEL) are the maximum allowable concentrations of hazardous substances in the workplace.

• H2S: PEL is 10 ppm (parts per million) over an 8-hour workday

• CO: PEL is 50 ppm over an 8-hour workday

• CO2: No specific PEL, but recommended exposure limit is 5,000 ppm over an 8-hour workday

• Methane: No specific PEL, but recommended exposure limit is 1,000 ppm over an 8-hour workday

Short term exposure limit (STEL) of H2S is 10 ppm.

• STEL is the maximum concentration of a substance that a worker can be exposed to for a short period of time without suffering from immediate or long-term health effects.

• The STEL for H2S is set at 10 ppm (parts per million) by OSHA (Occupational Safety and Health Administration).

• Exposure to H2S at levels above the STEL can cause symptoms such as eye irritation, headache,...read more