Boiler Operators Exam Correctly Solved

Boiler Operators Exam Correctly Solved At 0 pounds per square inch (psi), how many Btu are necessary to change 1 lb of water at 212 degree Fahrenheit into 1 lb of STEAM - 970 Btu What is Radiation? - A form of heat transfer by waves What is Superheated steam? - Steam at 100 psi and at 400 Fahrenheit Heat quantity that can be felt or measured by a thermometer - Sensible Heat Temperature required to raise 1 lb of water from 32 degree Fahrenheit to 212 degree Fahrenheit - 180 Btu Increasing the pressure has what effect on the boiling point of water. - Temperature will be raised Heat absorbed by water when it changes from liquid to steam at the boiling point is called? - Latent Heat Heat may be transferred in how many ways? - Three ways: Radiation, Conduction, Convection How is a boiler horsepower defined - Evaporation of 34.5 lb of water from and at 212 degree Fahrenheit per hour. What does 212 degree Fahrenheit equal on the Celsius scale? - 100 One boiler horsepower is equal to how many Btu? - 33,472 Btu A British thermal unit is ... - The amount of heat needed to raise one pound of water one degree Fahrenheit Hydronic heat is .... - Hot water heat Superheated steam is ... - Reheated Steam What does 2,545 Btuh represents - 1 Horsepower-hour A throttling calorimeter is used to measure the quality of ... - Saturated Steam What do you call Saturated Steam? - As long as there's some liquid water left, the steam's temperature is the same as the liquid water's. Steam is then called saturated steam. What do you call Superheated Steam? - When all the water is vaporized, any subsequent addition of heat raises the steam's temperature. Steam heated beyond the saturated steam level is called superheated steam The amount of heat in one pound of saturated steam is approximately equal to? - 1,150 Btu. A boiler operating at 100 pounds per square inch (psi) has dry saturated steam temperature of 338 degrees Fahrenheit. What is the boiler's water temperature? - 338 degree Fahrenheit A dry pipe is used to ... - Separate moisture from steam as it leaves the drum. The boiler vent valve is located on the... - top of the steam drum The purpose of the hole in the end of the staybolt is to ... - Indicate that a staybolt is cracked or broken A fusible plug melts at ... - 450 degrees Fahrenheit As the firing rate increases in a boiler equipped with a convection superheater, the steam temperature ... - increases It is permissible to have only one botttom blowdown valve on a boiler when the ... - Maximum Allowable Working Pressure (MAWP) does not exceed 100 psi. It is required that extra-heavy pipe be used on the blowoff system only when the boiler pressure exceeds what pressure? - 125 pounds per square inches (psi) Baffles are placed between the tubes of a boiler for the purpose of ... - directing the travel of flue gases A boiler has a steaming capacity of 35,500 lb of steam per hour. The evaporation rate is 10 pounds per square foot (lb/ft2) of heating surface per hour. What is the horsepower rating of this boiler? - 1,000 horsepower Boiler tube sizes are specified by ... - Outside Diameter (OD) The maximum size of boiler blowdown lines, valves, and fittings shall not exceed? - 2-1/2 inches The purpose of an expansion tank in a hot water heating system is to provide for the expansion of ... - water Heavy accummulation of soot in a boiler will result in ... - loss of boiler efficiency. How are the tubes secured in a fire-tube boiler? - Rolled and beaded over A tube in a fire-tube boiler is surrounded by ... - water Atmospheric pressure is considered to be... - 14.7 pounds per square inch absolute (psia) In a water-tube boiler... - flue gas surrounds the tube Diagonal stays are found in ... - fire-tube boilers Why are handholes and manholes oval? - for removal from a pressure vessel. What do you use to check the water level in the gauge glass of a steam boiler? - Use the trycocks A high-pressure boiler has its safety valve set above. - 15 pounds per square inch (psi) Which of the following is an advantage of fire-tube boilers over water-tube boilers? - Low initial cost where are water walls are found? - In water-tube boiler furnaces. When is the best time to bottom blow a boiler? - during low load and under full pressure. Where is a telltale hole is found? - In a staybolt A 2 inch boiler tube has a wall thickness of 3/16 inch. What is its inside diameter (ID)? - 1-5/8 inches At what temperature does Steel start to rapidly lose its strength? - 700 degrees Fahrenheit A hot-water heating system is about to be started. How full of water should the expansion tank gauge glass be? - One third full What is the relationship between longitudinal stress and circumferential stress? - Longitudinal stress is twice circumferential stress. A therm is equal to how many Btu? - 100,000 Btu What is the factor of evaporation? - The heat added to the boiler divided by 970.3 What is the purpose of a bottom blowdown? - To remove sludge and sediment What does damage to the spalling refers to? - The refractory What do Superheaters raise the temperature of? - Steam What is the steam space? - It is the area above the operating water level. What area is the heating surface of the boiler? - It is the area exposed to the flame and flue gases. What is the purpose of the superheater? - To heat steam above its saturation temperature What is Saturated Vapor? - The Maximum limit of water-vapour that a given quantity of air can hold at a particular temperature. In this case relative humidity will be 100 percent. What is the formula for the Factor of Evaporation? - H - b / 970.3 Btu What can cause a superheater tube to overheat? - A dirty tube A boiler has a steaming capacity of 34,000 lb of steam per hour. The evaporation rate is 10 pounds per square feet (lb/ft2) of heating surface per hour. What is the boiler heating surface? - 3,450 How many square feet of heating surface does a 3-inch fire-tube 20 ft long with a 3/17-inch wall have? - 13.7 feet of square surface In a high-temperature hot water boiler, what would cause a tube to overheat? - Poor circulation (plugged tube) Where do you find a downcomer located? - It is found in a water-tube boiler What can happen due to extreme firebox temperature changes? - Spalling What does the low-water cutoff limit do? - It shuts off the burner when the boiler is low on water. What would steam coming from the bottom try cock indicate? - It would indicate a low water level What type of valve has the most resistance to flow? - The Globe valve What should you do when checking the water level of a boiler? - Blow down the gauge glass and water colum