DC Boiler Exam Formulas and Equations, Exams of Mathematical Physics

Download DC Boiler Exam Formulas and Equations and more Exams Mathematical Physics in PDF only on Docsity! DC Boiler Exam 2023 exam Latest updated with assured success% 1. Area of a rectangle - ☑☑️☑️L️ength x Width P a g e 1 | 92 2. Area of a Circle - ☑☑️☑️.️7854 x Diameter² 3. Volume of a Box - ☑☑️☑️L️ength x Width x Height 4. Volume of a Cylinder - ☑☑️☑️.️7854 x Diameter² x Length P a g e 2 | 92 13. Formula for Mechanical Horsepower - ☑☑️☑️=️ Power ÷ 33,000 ft-lb/min 14. Fahrenheit to Celsius - ☑☑️☑️°️C = (°F - 32) ÷ 1.8 15. Celsius to Fahrenheit - ☑☑️☑️°️F = (1.8 x °C) - 32 16. Fahrenheit to Rankine - ☑☑️☑️°️R = °F + 460 P a g e 5 | 92 17. Celsius to Kelvin - ☑☑️☑️K️ = °C +273.15 18. Charles' First Law - ☑☑️☑️V️olume1 / Pressure1 = Volume2 / Pressure2 19. Charles' Second Law - ☑☑️☑️P️ressure1 / Temperature1 = Pressure2 / Temperature2 P a g e 6 | 92 20. Boyle's Law - ☑☑️☑️P️ressure1 x Volume1 = Pressure2 x Volume2 21. General Gas Law - ☑☑️☑️(️Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2 22. Formula for Levers - ☑☑️☑️R️esistance x DistanceR = Effort x DistanceE P a g e 7 | 92 30. D = Diameter 31. L = Length 32. t = thickness of steel 33. Boiler Heating Surface (tubes) = - ☑☑️☑️=️ C x L x # 34. C = Circumference of tubes 35. L = Length of tubes 36. # = Number of tubes 37. HS = π x Diameter x Length x Number of Tubes P a g e 10 | 92 38. Watts per Boiler Horsepower - ☑☑️☑️7️46 Watts 39. Horsepower formula - ☑☑️☑️=️ ft-lb/min ÷ 33000 ft- lb/min 40. ft-lb formula for a pump - ☑☑️☑️=️ gpm x 8.33 x head (ft) P a g e 11 | 92 41. Factor of Evaporation (FE) = - ☑☑️☑️=️ [Hs - (tfw-32)] ÷ 970.3 42. Hs = Enthalpy of steam 43. tfw = temperature of feed water 44. Latent Heat of Vaporization for Water - ☑☑️☑️9️70.3 Btu/lb 45. Latent Heat of Fusion for Water - ☑☑️☑️1️44 Btu/lb P a g e 12 | 92 53. Developed Boiler Horsepower (DBHP) = - ☑☑️☑️=️ (Pounds of Steam per hour (Ws) x FE) ÷ 34.5 54. Ws = Lbs of steam per hour 55. FE = Factor of Evaporation 56. Maximum Allowable Working Pressure (MAWP) - ☑☑️☑️=️ (TS x t x E) / FS x r 57. TS = Tensile Strength of steel P a g e 15 | 92 58. t = thickness of steel 59. E = Efficiency of joint 60. FS = Factor of Safety 61. r = radius of boiler drum 62. Bursting Pressure (BP) - ☑☑️☑️=️ (TS x t x E) / r 63. TS = Tensile Strength of steel 64. t = thickness of boiler plate 65. E = efficiency of joint 66. r = radius of boiler shell P a g e 16 | 92 67. Expansion (E) of Piping = - ☑☑️☑️=️ L x Cle x (T1 - T2) x 12 68. L = Length of pipe 69. Cle = Coefficient of linear expansion 70. T = Temperature 71. Capacity of a Reciprocating Pump in gpm = - ☑☑️☑️=️ (L x A x N x E ) / 231 72. L = Length of stroke 73. A = Area of water piston P a g e 17 | 92 82. Thermal Efficiency (TE) - ☑☑️☑️=️ Ws x [Hs -(fwt - 32)] / Wf x C 83. Ws = Weight of steam in lbs 84. Hs = Entalpy of steam 85. fwt = feed water temp. 86. Wf = Weight of fuel 87. C = Heat content per unit of fuel 88. Evaporation Rate (Where feedwater heat content of P a g e 20 | 92 setam are constant) - ☑☑️☑️W️s ÷ Wf 89. Ws = Steam flow in lbs / hr 90. Wf = Fuel flow in lbs / hour or therms / hour 91. Specific Gravity of Mercury (Hg) - ☑☑️☑️1️3.57 92. equivalent psi of water of 1" of Mercury - ☑☑️☑️.️491 psi P a g e 21 | 92 93. Atmospheric pressure in psi - ☑☑️☑️1️4.7 psi 94. Atmospheric pressure in in.Hg. - ☑☑️☑️2️9.29 in.HG 95. Lbs of air required to burn 1 lb of fuel - ☑☑️☑️1️5 lbs 96. % of oxygen in air - ☑☑️☑️2️1% P a g e 22 | 92 104. Formula for the horsepower requirement for a pump = - ☑☑️☑️(️Q x 8.33 x H x sp.gr. ) / 33,000 x n 105. Q = flow rate in gpm 106. H = total head 107. sp.gr. = specific gravity of fluid being pumped 108. n = Pump efficiency 109. 1 lb of chemical to 1000 gallons of water = x ppm - ☑☑️☑️1️20 ppm P a g e 25 | 92 110. Target pH for boiler water - ☑☑️☑️1️0.5 - 11.0 111. Target pH for condensate = - ☑☑️☑️8️.3 112. Target for Total Dissolved Solids (TDS) in steam boiler water - ☑☑️☑️2️000 - 2500 micromhos P a g e 26 | 92 113. Target for Total Dissolved Solids (TDS) in a hot water boiler - ☑☑️☑️3️500 micromhos 114. Water Horsepower = - ☑☑️☑️=️ (Q x H) / 3960 115. Q = flow rate in gpm 116. H = Head P a g e 27 | 92 130. n = pump efficiency 131. Critical pressure and temperature of steam - ☑☑️☑️3️206 psia @ 705°F 132. Above ____°F & ______ psi a hot water boiler is considered "high pressure" - ☑☑️☑️2️50°F & 160 psi P a g e 30 | 92 133. Max pressure for a fire tube boiler - ☑☑️☑️2️50-350 psi 134. Max horsepower of a fire tube boiler - ☑☑️☑️7️50- 1000 HP 135. If a stay bolt is longer than 8", then it is considered a ____ - ☑☑️☑️T️hrough stay P a g e 31 | 92 136. A 10°F rise in feed water temperature results in a ____ increase in efficiency - ☑☑️☑️1️% 137. There are ___ gallons in a cubic foot of water - ☑☑️☑️7️.5 galons 138. Pop type safety valves work up to ___ psi - ☑☑️☑️6️00 psi P a g e 32 | 92 144. A three element feedwater heater responds to ____ - ☑☑️☑️w️ater level, steam flow, & feedwater flow 145. #2 fuel oil contains approximately ______ Btu/gal - ☑☑️☑️1️41,000 P a g e 35 | 92 146. #6 fuel oil contains approximately _____ Btu/gal - ☑☑️☑️1️55,000 147. Fuel oil weighs approximately ___ lbs/gal - ☑☑️☑️8️ lbs 148. Air is approximately ___ % oxygen and ___ % nitrogen - ☑☑️☑️2️1, 79 P a g e 36 | 92 149. Formula for three phase kW - ☑☑️☑️(️E x I x PF x 1.732) ÷ 1000 150. Ohm's Law - ☑☑️☑️E️ = I x R 151. I Btu = ____ ft-lb - ☑☑️☑️7️78 152. T /F - Dissolved Oxygen can be converted to free P a g e 37 | 92 158. When is continuous blowdown most effective? - ☑☑️☑️D️uring heavy steaming 159. How can permanent hardness of water be reduced? - ☑☑️☑️B️y the use of chemicals or distillation 160. Where does dissolved CO2 in the boiler feedwater P a g e 40 | 92 cause corrosion? - ☑☑️☑️C️ondensate system 161. Dissolved CO2 in boiler feedwater forms what compound that causes corrosion? - ☑☑️☑️C️arbonic acid 162. Why add phosphates to boiler water? - ☑☑️☑️C️onverts scale forming salts to non-adhering sludge P a g e 41 | 92 163. Excess oxygen present bin the boiler water would be a direct indication of? - ☑☑️☑️I️mproper operation of the dearating feedwater tank 164. Cheleants do what when added to boiler water? - ☑☑️☑️C️onvert calcium, magnesium, and iron to non- adhering sludge P a g e 42 | 92 have on the activity of oxygen entrained in boiler feedwater? - ☑☑️☑️O️xygen is less active with high temperatures and pressures 170. Define titration - ☑☑️☑️A️ procedure of neutralizing an unknown solution with a reagent of a known quantity P a g e 45 | 92 171. The three basic classifications of impurities found in natural water are? - ☑☑️☑️d️issolved solids, dissolved gasses, suspended solids 172. What is the condition in which boiler metal becomes too brittle because of crystalline cracking? - ☑☑️☑️C️austic embrittlement P a g e 46 | 92 173. Temporary hardness of water can be reduced by ____ the water. - ☑☑️☑️h️eating 174. The ____ layup method is used for long term boiler storage. - ☑☑️☑️D️ry 175. An anion is an atom with a ____ electrical charge? - ☑☑️☑️n️egative P a g e 47 | 92 181. A ____ amine is injected into a boiler during operation to raise the pH of the condensate. - ☑☑️☑️N️eutralizing 182. Two testing instruments used to determine the quantity of dissolved iron in a water sample are the ____ and ____. - ☑☑️☑️C️olor P a g e 50 | 92 wheel comparator and spectrophotometer 183. ______ cause hardness particles in boiler water to precipitate as heavy sludge that is removed through the bottom blow. - ☑☑️☑️P️hosphates 184. _____ keeps the hardness in boiler water in solution so that it cannot P a g e 51 | 92 settle out on the heating surfaces. - ☑☑️☑️C️helants 185. _______ in boiler water contributes to the formation of CO2. - ☑☑️☑️H️igh Alkalinity 186. Pits of holes in iron or steel caused by excessive oxygen are called ____. - ☑☑️☑️T️ubercles P a g e 52 | 92 192. Superheater safety valves are set at a pressure ____ than the boiler drum safety valves. - ☑☑️☑️L️ower 193. A steam pressure gauge should have a range at least _____. - ☑☑️☑️1️-1/2 times the safety valve setting P a g e 55 | 92 194. In steam tables, heat in liquid (h) equals _____. - ☑☑️☑️T️otal heat (hg) - latent heat (Hfs) 195. Equation for determining theoretical water HP of a centrifugal pump - ☑☑️☑️=️ (Feet of Head x Pounds water/min) ÷ 33,000 P a g e 56 | 92 196. One kW = ____ HP - ☑☑️☑️1️.34 197. The minimum size connection between the gauge glass and water column is ____. - ☑☑️☑️1️" 198. Too little excess air can cause _____. - ☑☑️☑️S️moky fire P a g e 57 | 92 203. Electrostatic precipitators are used to ____. - ☑☑️☑️r️emove flyash and soot from boiler exhaust 204. The total pressure of a confined mixture of gases is the sum of the pressures of each of the gases in the mixture is known as ______. - ☑☑️☑️D️alton's law P a g e 60 | 92 205. Type L copper tubing is sized by - ☑☑️☑️I️nside diameter 206. ACR tubing is sized by - ☑☑️☑️O️utside diameter 207. When moisture is present in a refrigeration system it will react with the refrigerant and oil to form ____. - ☑☑️☑️A️cid P a g e 61 | 92 208. The difference between system overshoot and system lag is called _______. - ☑☑️☑️T️emperature swing 209. Typical superheat for an evaporator operating under normal conditions - ☑☑️☑️8️- 12 degrees P a g e 62 | 92 215. Boiler waterwalls should be blown down ______. - ☑☑️☑️w️hen the firebox is cool but the boiler has pressure 216. Safety valves should not be tested unless the boiler pressure is at least ___% of the set pressure. - ☑☑️☑️7️5% P a g e 65 | 92 217. The Btu content of natural gas is ____ Btu per ____. - ☑☑️☑️1️00,000; therm 218. Fuel oil with a low flash point is - ☑☑️☑️d️angerous to handle 219. The bypass damper on an air heater _____. - ☑☑️☑️p️revents corrosion at low rating by preventing the stack temperature from P a g e 66 | 92 dropping below the dew point of the air. 220. Steam at 100psi has a corresponding temperature of _____. - ☑☑️☑️3️37.9°F 221. According to ASME Code, a boiler pressure gauge should have a range of - ☑☑️☑️1️-1/2 - 2 times the safety valve setting P a g e 67 | 92 227. What type of flame scanner sensor senses visible light? - ☑☑️☑️P️hotocell 228. What type of flame scanner sensor is sensitive to infrared light? - ☑☑️☑️L️ead sulfide 229. According to ASME Code, when warming up a boiler during cold plant startup, the boiler vent P a g e 70 | 92 should remain open until the steam pressure reaches approximately ____ psi. - ☑☑️☑️2️5 psi 230. Where is the feedwater element located? - ☑☑️☑️A️t the NOWL 231. What should the boiler operator do if steam comes out of the bottom trycock when testing it? - P a g e 71 | 92 ☑☑️☑️S️ecure the fires to the boiler, allow the boiler to cool slowly, and notify the chief engineer 232. On what type of coal stoker is an ignition arch used? - ☑☑️☑️c️hain grate 233. In which type of boiler are staybolts most commonly used? - ☑☑️☑️f️iretube boiler P a g e 72 | 92 boiler start up? - ☑☑️☑️t️he superheater drain 239. What is the lowest temperature at which fuel will flow called? - ☑☑️☑️p️our point 240. The lowest temperature at which fuel oil will burn continuously is the_____. - ☑☑️☑️f️ire point P a g e 75 | 92 241. According to ASME Code how often should a boiler be blown down when no boiler water analysis is done? - ☑☑️☑️e️very 24 hours 242. Boiler CO2 readings of 12.5% over fire, 11.5% in the second pass, and 8% at the damper indicate____? - ☑☑️☑️l️eaks through the boiler side wall P a g e 76 | 92 243. How much pressure is applied to a boiler during a hydrostatic test? - ☑☑️☑️1️- 1/2 times the MAWP 244. The size of the bottom blowdown lines can be reduced when ______. - ☑☑️☑️t️he boiler has less than 100 ft² of heating surface P a g e 77 | 92 250. What is required to burn pulverized coal efficiently? - ☑☑️☑️a️ high furnace temperature 251. A sudden increase in stack temperature without a corresponding increase n steam demand indicates what? - ☑☑️☑️a️ broken baffle P a g e 80 | 92 252. What percentage of steam generated in a boiler is used for the steam atomizing burner? - ☑☑️☑️4️% 253. What does a proximate analysis of coal determine? - ☑☑️☑️w️eight of moisture, fixed carbon, volatile matter, and ash content P a g e 81 | 92 254. Try cocks are not effective above what steam pressure? - ☑☑️☑️2️50 psi 255. What test determines if the safety valve(s) of a steam boiler have sufficient relieving capacity? - ☑☑️☑️a️ccumulation test 256. Carbon dioxide in flue gas is an indication of what? - ☑☑️☑️c️omplete combustion P a g e 82 | 92 operated main steam stop valves, the steam pressure on the incoming boiler should be _______. - ☑☑️☑️s️lightly lower than the line pressure 262. After replacing the gauge glass but before placing it in service, it is necessary to _____. - ☑☑️☑️c️rack open the steam valve and warm the glass P a g e 85 | 92 263. What protects a steam pressure gauge from the high temperature of the steam? - ☑☑️☑️a️ siphon 264. What is the minimum size of a manhole on a boiler? - ☑☑️☑️1️1" x 15" 265. The amount of excess air in gases of combustion is P a g e 86 | 92 normally determined by the analysis of ____. - ☑☑️☑️O️2 266. Equivalent evaporation = - ☑☑️☑️W️s x FE 267. Ws = weight of steam in lbs/hr 268. FE = Factor of evaporation 269. What is the purpose of a bridge wall in the furnace of an HRT boiler? - ☑☑️☑️T️o P a g e 87 | 92 Registration Number, Burner Rating in Btu input 273. What are the three types of stress - ☑☑️☑️C️ompression, Tension, and Shear 274. Hopw are the shells of HRT boilers suspended? - ☑☑️☑️L️ug-and-roller or overhead suspension P a g e 90 | 92 275. What is the size of handholes? - ☑☑️☑️4️" X 5" 276. Theoretical natural draft - ☑☑️☑️D️=0.52HP(1/T1-1/T2) 277. D = Draft at base of chimney 278. H = Height of chimney 279. P = atmospheric pressure (normally 14.7 psia) 280. T1 = Outside air temperature in °Rankin P a g e 91 | 92 281. T2 = Stack temperature in °Rankin 282. One cubic foot of water is equal to ____ gallons - ☑☑️☑️7️.49 gal P a g e 92 | 92