DC Boiler Exam Prep 2024 Update 215+ Questions and Verified Correct Answers Already Graded A+ _____ keeps the hardness in boiler water in solution so that it cannot settle out on the
heating surfaces. - CORRECT ANSWER: Chelants
______ cause hardness particles in boiler water to precipitate as heavy sludge that is
removed through the bottom blow. - CORRECT ANSWER: Phosphates
_______ in boiler water contributes to the formation of CO2. - CORRECT
ANSWER:High Alkalinity
#2 fuel oil contains approximately ______ Btu/gal - CORRECT ANSWER: 141,000
#6 fuel oil contains approximately _____ Btu/gal - CORRECT ANSWER: 155,000
% of oxygen in air - CORRECT ANSWER: 21%
- BHP = x ft² of heating surface (general) - CORRECT ANSWER: 10 ft² heating surface
1 Boiler Horsepower = x Btu/hr - CORRECT ANSWER: 33,475 Btu/hr
1 Boiler Horsepower = x lbs of steam generator per hour - CORRECT ANSWER: 34.5
lbs/hr
1 lb of chemical to 1000 gallons of water = x ppm - CORRECT ANSWER: 120 ppm
A ____ amine is injected into a boiler during operation to raise the pH of the
condensate. - CORRECT ANSWER: Neutralizing
A _____ test is a test that determines the concentration of a specific dissolved
substance. - CORRECT ANSWER: Titration
A 10°F rise in feed water temperature results in a ____ increase in efficiency -
CORRECT ANSWER: 1%
A dearator stores how much feedwater? - CORRECT ANSWER: 20-30 minutes supply
A demineralizer is usually used with ____ pressure boilers - CORRECT ANSWER: High
A flash tank____ - CORRECT ANSWER: Recovers low pressure steam
A reciprocating pump is a ___ type pump. - CORRECT ANSWER: positive
displacement 1 / 2
A saybolt viscometer is used for _____. - CORRECT ANSWER: testing and grading of oils
A single element feedwater heater responds to ____ - CORRECT ANSWER: water
level
A steam pressure gauge can be calibrated with a _____. - CORRECT
ANSWER:deadweight tester
A steam pressure gauge should have a range at least _____. - CORRECT
ANSWER:1-1/2 times the safety valve setting
A sudden increase in stack temperature without a corresponding increase n steam
demand indicates what? - CORRECT ANSWER: a broken baffle
A three element feedwater heater responds to ____ - CORRECT ANSWER: water level, steam flow, & feedwater flow
A two element feedwater heater responds to ____ - CORRECT ANSWER: water level & steam flow
A(n) _____ analysis is used to determine the percentage of various elements contained in coal, including carbon, oxygen, nitrogen, hydrogen, sulphur, and ash. - CORRECT
ANSWER:ultimate
A(n) _____ test is performed on a boiler to check the operation of the low water fuel cutoff by allowing the water level in the boiler to drop slowly. - CORRECT
ANSWER:Evaporation
Above ____°F & ______ psi a hot water boiler is considered "high pressure" -
CORRECT ANSWER: 250°F & 160 psi
According to ASME Code how often should a boiler be blown down when no boiler
water analysis is done? - CORRECT ANSWER: every 24 hours
According to ASME Code, a boiler pressure gauge should have a range of - CORRECT
ANSWER:1-1/2 - 2 times the safety valve setting
According to ASME code, the maximum size of the boiler bottom blowdown line is
_____. - CORRECT ANSWER: 2-1/2"
According to ASME Code, what must a boiler with more than 500 ft² of heating surface
have? - CORRECT ANSWER: two or more safety valves
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