Scania Steel & Power Mechanical Head Interview Questions and Answers

A centrifugal pump is a mechanical device used to transport fluids by converting rotational kinetic energy into hydrodynamic energy.

• Centrifugal pumps are commonly used in various industries, including oil and gas, water treatment, and HVAC systems.

• They work by using an impeller to rotate and create a centrifugal force, which pushes the fluid towards the pump outlet.

• The fluid enters the pump through the suction inlet an...read more

There are several types of valves used in mechanical systems.

• Gate valve: used to control the flow of fluid by lifting or lowering a gate

• Ball valve: uses a ball to control the flow of fluid

• Butterfly valve: uses a disc to control the flow of fluid

• Check valve: allows fluid to flow in one direction only

• Globe valve: controls flow by raising or lowering a plug

• Needle valve: uses a long, tapered needle to control flow

• Diaphragm...read more

A ball valve is a type of valve that uses a ball-shaped disc to control the flow of fluid through a pipe.

• Ball valves are commonly used in industrial applications for their durability and reliability.

• They have a simple design, consisting of a ball with a hole in the middle that can be rotated to control the flow of fluid.

• Ball valves can be either full port or reduced port, depending on the size of the ball and the hole.

• ...read more

A shell and tube heat exchanger is a device used to transfer heat between two fluids.

• Consists of a shell (outer vessel) and tubes (inner vessels)

• One fluid flows through the tubes while the other flows around the tubes in the shell

• Heat is transferred from one fluid to the other through the tube walls

• Commonly used in industries such as power generation, chemical processing, and HVAC

• Example: Cooling water in a power plant

There are several types of heat exchangers, including shell and tube, plate and frame, and finned tube.

• Shell and tube heat exchangers are the most common type and consist of a shell with tubes inside.

• Plate and frame heat exchangers use thin plates to transfer heat between fluids.

• Finned tube heat exchangers have tubes with fins attached to increase surface area for heat transfer.

• Other types include spiral, double pipe, ...read more

PPE stands for Personal Protective Equipment.

• PPE is equipment worn to minimize exposure to hazards that may cause serious workplace injuries or illnesses.

• Examples of PPE include safety glasses, gloves, hard hats, respirators, and safety shoes.

• PPE should be selected based on the specific hazards present in the workplace.

• Employers are responsible for providing PPE to their employees and ensuring that it is properly maint...read more

An axial flow pump is a type of pump that uses an impeller to create fluid flow parallel to the pump shaft.

• Axial flow pumps are commonly used in applications where large volumes of fluid need to be moved at low to medium pressures.

• They are often used in irrigation systems, drainage systems, and cooling systems.

• The impeller of an axial flow pump has blades that resemble a propeller, which helps in generating the axial f...read more

A check valve is a mechanical device that allows fluid to flow in one direction only.

• Check valves are commonly used in plumbing systems to prevent backflow of water.

• They are also used in hydraulic systems to prevent reverse flow of fluid.

• Check valves can be classified into different types such as swing check valves, lift check valves, and ball check valves.

• These valves work by using a disc or a ball that opens and clos...read more

Positive displacement pump is a type of pump that moves fluid by trapping a fixed amount of it and then forcing it into the discharge pipe.

• Positive displacement pumps operate by trapping a specific volume of fluid and then forcing it into the discharge pipe.

• These pumps are capable of generating high pressures and are used in various industries such as oil and gas, chemical, and food processing.

• Examples of positive disp...read more

A globe valve is a type of valve used to regulate or stop the flow of fluid in a pipeline.

• It has a spherical body with an internal baffle that directs the flow of fluid.

• The valve can be opened or closed by rotating the stem.

• It provides a tight seal when closed, preventing leakage.

• Globe valves are commonly used in applications where throttling or regulating flow is required.

• They are often found in water systems, steam s

PPE stands for Personal Protective Equipment. It refers to protective clothing, helmets, goggles, or other equipment designed to protect the wearer's body from injury or infection.

• PPE is used in various industries to protect workers from hazards.

• Examples of PPE include safety glasses, gloves, hard hats, respirators, and earplugs.

• PPE should be selected based on the specific hazards present in the workplace.

• Proper traini...read more

The number of stages of turbine blades varies depending on the specific turbine design and application.

• Turbine blades are used in various applications such as gas turbines, steam turbines, and wind turbines.

• The number of stages in a turbine refers to the number of sets of rotating and stationary blades.

• Each stage of turbine blades helps to extract energy from the fluid passing through the turbine.

• Gas turbines typically...read more

The total number of bearings in a turbine varies depending on its design and size.

• The number of bearings in a turbine can range from a few to several dozen.

• The main purpose of bearings in a turbine is to support rotating components and reduce friction.

• Different types of bearings, such as ball bearings or roller bearings, may be used in a turbine.

• Large turbines, such as those used in power plants, typically have more be...read more

Steam enters the turbine at the high-pressure stage.

• Steam enters the turbine at the high-pressure stage to maximize energy extraction.

• The high-pressure steam is directed into the turbine blades, causing them to rotate.

• The steam then passes through multiple stages of the turbine, gradually losing pressure and expanding.

• At each stage, the steam's energy is converted into mechanical work to drive the turbine.

• Finally, the ...read more