10+ ZEST Interview Questions and Answers

Steam drum spare parts include level gauges, safety valves, blowdown valves, and pressure switches.

• Level gauges

• Safety valves

• Blowdown valves

• Pressure switches

Super heater tubes are typically made of alloy steel to withstand high temperatures and pressures.

• Super heater tubes are commonly made of materials like T11, T22, T91, etc.

• Alloy steel is preferred for its high temperature and pressure resistance.

• The material composition may vary based on the specific requirements of the boiler system.

A boiler is a closed vessel in which water or other fluid is heated.

• Boilers are used to generate steam or hot water for heating, processing, or power generation

• They can be fueled by natural gas, oil, coal, or electricity

• Boilers have pressure and temperature controls to ensure safe operation

Dearetor in chemical dosing % refers to the percentage of chemical dosing in the deaerator system.

• Dearetor in chemical dosing % is the amount of chemical added to the deaerator system to prevent corrosion and scale buildup.

• The percentage of chemical dosing can vary depending on the specific requirements of the system and the type of chemicals being used.

• For example, a typical range for chemical dosing in a deaerator system might be between 0.5% to 2% of the total water flow.

• M...read more

Water wall tubes are typically made of carbon steel, stainless steel, or alloy steel to withstand high temperatures and pressure.

• Water wall tubes are commonly made of carbon steel due to its cost-effectiveness and durability.

• Stainless steel water wall tubes are used in applications where corrosion resistance is important.

• Alloy steel water wall tubes are preferred for high-pressure and high-temperature environments.

• Common materials used for water wall tubes include SA-178, SA-...read more

Super heater steam speed is the velocity at which steam flows through the super heater tubes.

• Super heater steam speed is typically measured in meters per second or feet per minute.

• Higher steam speeds can increase heat transfer efficiency in the super heater.

• Proper steam speed is crucial to prevent overheating or underheating of the super heater tubes.

Total moisture in coal refers to the moisture content present in coal including both surface moisture and inherent moisture.

• Total moisture in coal is the sum of surface moisture and inherent moisture.

• Surface moisture is the moisture present on the surface of coal particles, while inherent moisture is the moisture contained within the coal itself.

• Total moisture affects the calorific value and combustion efficiency of coal.

• High total moisture content in coal can lead to increas...read more

Slop in total oxygen % refers to the amount of oxygen present in the slop being used in the boiler operation.

• Slop in total oxygen % is an important parameter to monitor in boiler operation as it affects combustion efficiency.

• High levels of oxygen in slop can indicate incomplete combustion, leading to energy loss and increased emissions.

• Regular monitoring and adjustment of oxygen levels in slop can help optimize boiler performance and reduce environmental impact.

Silica in DM water can cause scaling and corrosion in boiler systems.

• Silica in DM water can lead to scaling on boiler tubes and heat exchangers.

• High levels of silica can also cause corrosion in boiler systems.

• Regular monitoring and treatment of DM water is essential to prevent silica buildup.

• Examples of treatment methods include ion exchange resins and reverse osmosis systems.