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) The number of pounds of steam generated per hour at the pressure and temperature required for all purposes to develop contract shaft horsepower of the ship divided by the numbers of boilers installed is defined as? - Answer Boiler full power capacity 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 3. End point of combustion How are individual economizer tubes connected? - Answer By U-bends at the tube ends What type of refractory is preferred for small repairs or where standard size brick or tile cannot be used? - Answer Castable fireclay