Main propulsion Boiler Operation Exam Questions With Correct Answers, Latest Updated 2024/2025 (GRADED)

Main propulsion Boiler Operation Exam Questions With Correct Answers, Latest Updated 2024/2025 (GRADED) Boiler overload capacity is normally what percentage of boiler full power capacity? - Answer 120% A pressure specified by the boiler manufacturer as a criterion for the boiler design is termed as? - Answer Design pressure What is the minimum steam drum pressure on an operating boiler? - Answer 85% of boiler operating pressure What is the minimum steam drum pressure on an operating boiler? - Answer 85% of boiler operating pressure What type of circulation would installing the generating tubes at an increased inclination be? - Answer Accelerated natural What type of boiler consists of one or more water drums? - Answer Drum type Do header type boilers have a water drum? - Answer No. The term high pressure boiler refers to a boiler operating at what pressure? - Answer 751 psi or above What two sheets of steel make up the construction of the steam drum? - Answer Wrapper sheet and tube sheet. What purpose do the generating tubes serve? - Answer Provide the area in which most of the saturated steam is generated. What is the function of the waterwall tubes? - Answer To protect furnace refactories, and allow a higher heat release. Water screen tubes protect the superheater from what? - Answer Direct radiant heat Main propulsion Boiler Operation Exam Questions With Correct Answers, Latest Updated 2024/2025 (GRADED Answers) What is installed between the inner and outer casings of the boiler to carry the downward flow of relatively cool water and thus maintain the boiler circulation? - Answer Downcomers What portion of the steam drum contains a manhole for access to the drum for cleaning, inspecting and repair? - Answer Drumhead Which tubes at high firing rates do not generate steam? - Answer Downcomers What boiler component preheats the feedwater prior to its entering the steam drum? - Answer Economizer What function do the metal projections on the economizer tubes serve? - Answer To extend the heat transfer surface of the tubes. What is the heating source of the economizer? - Answer Combustion gases What is the standard size of firebrick? - Answer 2 1/2" X 4 1/2" X 9" Insulating block is capable of withstanding surface temperature of? - Answer 1500 Degrees F What joins the boiler to the smoke pipe? - Answer Uptakes Refractory expansion joints are normally what size? - Answer 1/4" What is the preferred material for expansion joints construction? - Answer Styrofoam A boiler purge will have how many volumetic air changes? - Answer 5 A boiler must always be purged in accordance with what? - Answer Purge table During a furnace inspection prior to light off the boiler inspection device (bid) fogs up, what is the probable cause? - Answer Presence of fuel oil in the furnace Can raw fuel be removed from the furnace by purging the boiler? - Answer No, the fuel must be wiped up. Once the boiler purge is complete, fires must be lighted within what time frame? - Answer 5 Minutes If ignition fails to occur within 2 to 3 seconds what action must be taken? - Answer Shut the burner fuel oil manifold valve, safety shutoff device and investigate the cause. During a heavy black smoke condition the burner flame will be what color? - Answer Dark Orange An incandescent dazzling white burner flame is an indication of what? - Answer Excessive air Fuel oil temperature at the burner front shall not exceed what temperature? - Answer 125 Degrees F What is the function of the boiler sliding feet? - Answer To allow for expansion and contraction of the boiler during light off and cool down. The steam separators separate the steam and water mixture by what action? - Answer Centrifugal action The majority of the steam that leaves the superheater goes where? - Answer Main engines A short term decrease in drum water level which results from a change in firing rate or steam flow without any corresponding change in the feeding rate is termed what? - Answer Shrink The amount of heat applied to steam to raise its temperature above the saturation temperature, while maintaining constant pressure is defined as? - Answer Superheat What is the basic cause of all boiler explosions? - Answer 10 to 15 seconds per 90 degrees rotation The minimum steam atomization temperature at the burner front is? - Answer 370 Degrees F The desired range of steam atomization temperature is? - Answer 400 Degrees F, plus or minus 10 degrees F What prevents windmilling of an idle force draft blower, while the other force draft blower is online? - Answer Automatic shutters The chock facing of the sliding feet is constructed of what material? - Answer Phosphorous bronze What term is usually attributable to deficiency of air and excessive vibration of the boiler? - Answer Panting Heavy and prolonged seawater contamination of the fuel oil will for what type of corrosive products on the brick work? - Answer Slag formation What function does nichrome wire serve in the refractory? - Answer As a anchoring device A boiler the provides some means of controlling the degree of superheat independently of the rate of steam generation is said to have? - Answer Controlled superheat Most modern naval boilers are designed for what type of circulation? - Answer Accelerated natural circulation What is the function of refractory materials? - Answer To confine the heat to the firebox and protect the casing and structural members from overheating. What are the three end points a steaming boiler has? - Answer 1. End point of circulation 2. End point of moisture carryover