20+ Hitachi Interview Questions and Answers

Sieves are often round in shape due to their efficiency in separating particles evenly.

• Round shape allows for equal distribution of particles across the sieve

• Round shape minimizes the chances of particles getting stuck in corners or edges

• Round sieves are easier to handle and stack compared to other shapes

• Round shape promotes better flow of materials through the sieve

The type of reactor is a crucial factor in pharmaceutical, chemical, and biochemical processes.

• Reactors are vessels or systems used to carry out chemical reactions.

• Different types of reactors are used depending on the specific process requirements.

• Common types of reactors include batch reactors, continuous flow reactors, and stirred tank reactors.

• Batch reactors are used for small-scale production or when precise control of reaction conditions is required.

• Continuous flow react...read more

If motor stator core is short, maintenance in HT panel and transformer is necessary.

• Isolate the affected equipment and de-energize it

• Check the insulation resistance of the equipment

• Identify the cause of the short circuit and repair or replace the affected parts

• Perform regular maintenance on the HT panel and transformer to prevent future issues

• Consider innovative modifications to improve the efficiency and reliability of the equipment

Centrifuge pump power and capacity calculations involve understanding the pump's efficiency, flow rate, and head.

• Calculate the pump's power using the formula: Power (kW) = (Q x H x SG) / (3.6 x η)

• Determine the pump's capacity by calculating the flow rate (Q) in m^3/s

• Consider the pump's head (H) in meters and specific gravity (SG) of the fluid being pumped

• Efficiency (η) of the pump is crucial for accurate power calculations

• Example: If a centrifuge pump has a flow rate of 0.05 ...read more

MIG stands for Metal Inert Gas welding, while MAG stands for Metal Active Gas welding. The main difference lies in the type of shielding gas used.

• MIG welding uses inert gases like argon or helium to shield the weld pool from atmospheric contamination, while MAG welding uses active gases like carbon dioxide or a mixture of gases.

• MIG welding is typically used for non-ferrous metals like aluminum, while MAG welding is more suitable for ferrous metals like steel.

• MIG welding produ...read more

BIS stands for Bureau of Indian Standards.

• BIS is the national standards body of India.

• It is responsible for the development and implementation of standards across various sectors.

• BIS ensures quality, safety, and reliability of products and services.

• It provides certification and testing services to ensure compliance with standards.

• BIS marks are used to indicate that a product meets the required standards.

• Examples of BIS standards include IS 13432 for compostable plastics and I...read more

Plant parameters are key indicators of the performance and efficiency of a production facility. Safe operation involves adhering to set guidelines and protocols to prevent accidents and ensure worker safety.

• Plant parameters include temperature, pressure, flow rate, and level of various substances in the production process.

• Monitoring and controlling these parameters is crucial for maintaining optimal production conditions and preventing equipment failures.

• Safe operation involv...read more

PQR Process is a procedure used in welding to qualify the welding procedure specification.

• PQR stands for Procedure Qualification Record.

• It involves testing and documenting the variables used during the welding process.

• The purpose is to ensure that the welding procedure will produce the desired quality of welds.

• PQR Process is essential for ensuring the integrity and strength of welded joints.

• Examples of variables tested include welding parameters, material thickness, and joint...read more

The safety equipment per site is the responsibility of the site engineer.

• Ensuring all safety equipment is available and in working condition on site

• Regularly inspecting safety equipment to ensure compliance with regulations

• Training site personnel on proper use of safety equipment

• Maintaining records of safety equipment inspections and maintenance

• Coordinating with safety officers to address any safety equipment concerns

Emergency fault found for duties requires immediate action to resolve the issue and prevent any further damage or safety hazards.

• Identify the nature and location of the fault

• Assess the severity of the fault and potential impact on operations

• Implement immediate corrective actions to address the fault

• Communicate with relevant stakeholders to coordinate response and mitigation efforts

• Document the fault, actions taken, and outcomes for future reference

The working temperature of the Boiler DCS Operator is 400±5 °C and the working pressure is 45 kg/cm2.

• The Boiler DCS Operator is responsible for monitoring and controlling the temperature and pressure of the boiler.

• They need to ensure that the temperature is maintained within the range of 400±5 °C.

• They also need to ensure that the pressure is maintained at 45 kg/cm2.

• Any deviations from the specified temperature and pressure should be promptly addressed to prevent any potential...read more

GMP stands for Good Manufacturing Practice. It is a set of guidelines and regulations that ensure the quality and safety of pharmaceutical products.

• GMP is a system of quality assurance in the manufacturing process of pharmaceutical products.

• It includes guidelines for the design, monitoring, and control of manufacturing facilities and processes.

• GMP ensures that pharmaceutical products are consistently produced and controlled according to quality standards.

• It covers various asp...read more

The pH range of water is typically between 6.5 and 8.5.

• Water with a pH below 6.5 is considered acidic.

• Water with a pH above 8.5 is considered alkaline.

• The pH of water can vary depending on factors such as pollution, minerals, and dissolved gases.

• For example, rainwater is slightly acidic with a pH of around 5.6 due to the presence of carbon dioxide.

• Seawater has a pH of around 8.1, making it slightly alkaline.

A liquid ring compressor is a type of rotary positive displacement pump that uses a liquid seal to create compression.

• Uses a rotating impeller with blades to compress gas by creating a liquid ring around the impeller

• The liquid ring acts as a seal and helps in compression of gas

• Commonly used in applications where a continuous flow of gas with low pressure is required, such as in vacuum systems or wastewater treatment plants

GMAW stands for Gas Metal Arc Welding, a welding process that uses a continuous solid wire electrode and shielding gas to create a weld.

• Uses a continuous solid wire electrode

• Requires a shielding gas to protect the weld from atmospheric contamination

• Commonly used in industries like automotive, construction, and manufacturing

WPS Procee is a welding procedure specification that outlines the details of a specific welding process.

• WPS Procee includes information such as welding materials, welding parameters, preheat and post-weld heat treatment requirements.

• It is essential for ensuring consistency and quality in welding operations.

• WPS Procee is often required in industries such as construction, manufacturing, and oil & gas.

• Example: A WPS Procee document may specify the type of welding machine to be u...read more

A RVD is operated by setting the desired speed and time, loading the sample, and starting the machine. A centrifuge is operated by balancing the tubes, setting the desired speed and time, and starting the machine.

• For a RVD, make sure to properly load the sample and balance the rotor to avoid damage or inaccurate results.

• For a centrifuge, ensure that the tubes are properly balanced to prevent damage to the machine or samples.

• Set the desired speed and time for both machines acc...read more

MLSS stands for Mixed Liquor Suspended Solids. It is a measure of the concentration of suspended solids in wastewater treatment.

• MLSS is an important parameter in wastewater treatment plants.

• It is measured in mg/L or g/L.

• MLSS indicates the amount of microorganisms present in the wastewater treatment process.

• A higher MLSS concentration can lead to better treatment efficiency.

• MLSS can be controlled by adjusting the aeration rate and wasting rate in the treatment process.

The market size in each region varies based on factors such as population, economic conditions, and competition.

• Market size can be determined by analyzing the population of each region and their purchasing power.

• Economic conditions, such as GDP and disposable income, also play a role in determining market size.

• Competition in the region, including the number of competitors and their market share, affects the potential market size.

• Market research and data analysis can provide i...read more

Maintenance of power plant involves regular inspections, repairs, and upgrades to ensure efficient and safe operation.

• Regularly inspecting equipment for signs of wear and tear

• Performing routine maintenance tasks such as cleaning filters and lubricating moving parts

• Scheduling periodic shutdowns for major overhauls and upgrades

• Training staff on proper maintenance procedures and safety protocols

• Keeping detailed records of maintenance activities and equipment performance