DC 1st Class Boiler Test Questions with 100% Complete Solutions Graded to Pass

Moving blading in which space between blades is the same size at the blading inlet, and the blading outlet. - cORRECT sOLUTION Impulse Blading To blowdown a boiler equipped with a quick opening and slow opening valve on the bottom blowdown line, the_________. - cORRECT sOLUTION quick opening valve is opened first and closed last. Hardness of water is the measurement in ppm of ________ and ________ in the water. - cORRECT sOLUTION calcium and magnesium A pump delivers 175 gallons per minute against a pressure of 55 psi; the suction pressure is 15 psi. If a pump is 80% efficient, what is the horsepower needed? - cORRECT sOLUTION HP=5.1 HP= (Head in Feet) x (Weight in Lbs.)/ 33,000 x Efficiency a duplex double-acting reciprocating feed water pump has____ - cORRECT sOLUTION two steam Pistons 2 to 2 2/2 times larger in area than the water piston Name a technique to control the nitrous oxide emissions. - cORRECT sOLUTION Selective Catalytic Reduction Spalling in a boiler occurs in the ____? - cORRECT sOLUTION Combustion chamber A technology in which solid waste is heated in an oxygen starved atmosphere to break down the solids into a gas is called ______? - cORRECT sOLUTION Pyrolysis What is the primary purpose of using wet scrubbers? - cORRECT sOLUTION To remove sulfur dioxides The thermal efficiency of a boiler with a stack temperature of 750°F and and a furnace temperature of 3200°F is_______? - cORRECT sOLUTION 75% ((3200-750)/3200) x 100 ________is a water-purification process in which the water to be treated is pressurized and applied against the surface of a semipermeable membrane. - cORRECT sOLUTION Reverse osmosis The airflow switch at the burner fan housing______. - cORRECT sOLUTION Ensures the primary air fan is functioning How many inches of steam space in a cylinder of an engine 12"x28" and the stroke is 5/8 of its full travel? - cORRECT sOLUTION 1978. V=AxL V=3.14(6x6)x28x.625= 1978 What is the horsepower requirement of a pump that moves 2500 gpm of water against a head of 475' if the pump is operating at 58% efficiency? - cORRECT sOLUTION 516.8 HP=Head x Weight/33000 x efficiency. (Head =475, Weight = 2500gpm x 8.33) (475x 20825)/19140 A ______ is the condition that is being controlled - cORRECT sOLUTION process variable Although boiler tubes and boiler drums withstand the same pressure, the walls of the boiler tubes are much thinner because ______. - cORRECT sOLUTION The tubes are much smaller in diameter A lead sulfide cell detects_____. - cORRECT sOLUTION Burner pilot and main flame Which of the following indicates a malfunction in the DC heater? 1. The boiler requires excessive amounts of oxygen absorbing chemicals. 2.Water and steam are entering the DC heater at the same temperature. - cORRECT sOLUTION Both 1 & 2 ______ is the plasticity exhibited by a material under tension loading. - cORRECT sOLUTION Ductility In a pressure atomizing fuel oil-burner, atomization of fuel is produced by the _______. - cORRECT sOLUTION Burner tip and high pressure fuel