Stationary Engineer QUESTIONS AND ANSWERS 100% CORRECT GRADE A+ SOLUTIONS

How much clearance from the top of the boiler is needed for a HP boiler that produces 70000 lbs of steam? 7 feet On a gas fired boiler what is the proper gas to air mixture 30%-70% and in special arrangements it can be as high as 100% . ANSWER CHAPTER 11 remember% What is the total hardness in a system that was found to have calcium hardness of 60ppm and magnesium hardness of 18ppm and carbon hardness of 12 ppm? TH=(Ca x 2.5) + (Mg x 4.1)nTH=(60 x 2.5) + (18 x 4.1)nTH= 150+73.8 =( 223.8 PPM) How often should a complete external inspection of the boiler be done? Once a Shift With 24 hr operation how often do you check the water level? Once per shift How often do you check the LWCO? Once per shift How often do you check the High Limit Switch? Annually A 2" pipe was found to be delivering water at 100 psia at 1040ft per second. How many gallons per hour will it deliver? GPM= V (diameter squared) divided by .4085 ANSWER pg 469 BOG What controls the amount of blowback on a safety valve? Blowback ring or adjusting ring On a open air expansion tank hot water boiler system; how high should it be mounted? (4 Feet ) above the highest heating element. What is the minimum top clearance of boilers with manholes? 5 feet Package boilers; steam heating boilers and hot water heating boilers shall have a minimum clearance of? 2 feet from ceiling. Code chapter 10 page76 Most important safety device on a boiler? Safety relief valve What does a Black Liquor Boiler do? Black Liquor is the by product of wood pulp processing in the paper making industry. What does Black liquor boiler known for? Steam generation and recovery of soda ash Maximum line voltage for control on a boiler? 150 volts Under what code are boilers designed and constructed? ASME- CSD 1 How many low water cut offs are needed per code for a hot water system when a boiler has inputs greater than 400,000 btu per hr 1 LWCO is needed. What is the minimum and maximum size for a safety valve per code for boilers? Minimum 3/4" and Maximum 4 1/2" What stamp is put on a boiler after repairs? "R" What is the equalizing system used for? The equalizing system is for warming up the steam lead. A blowdown valve is located at the lowest water space of a boiler for three purposes 1. to remove precipitated sludge or loose scale n2. To permit rapid lowering of the boiler water if it has become too high accidentally n3. As a means of removing water from the boiler so that fresh water may be added to keep the concentration of solids below the point where difficulties may be experienced. In the old power boiler which type of feed-water regulators were not used? Electronic After opening a boiler for repairs how much oxygen is needed? 19% What is the first thing you do when shutting down a boiler? Turn off (extinguish fire) What is the legal limit of acceptable asbestos particles ? 0.1 fibers per cubic centimeter What is CREEP? Creep is defined as the slow deformation of material with time; with the deformation taking place at elevated temperatures with no increase in stress. What is the BTU content of Anthracite coal? 14000 btu/lb What substance transfers electrical current in a photocell? Electricity will flow when the CADMIUM is exposed to sufficient light. What device acts as a check valve in both directions and keeps pumps primed? FOOT VALVES are used for pumps under suction pressure to prevent backflow primed? on the suction line. What protects boilers from explosion in the furnace? A flame guard system is an arrangement of flame detection system; interlocks; and relays which will sense the presence of a proper flame in a furnace and cause fuel to be shut off to the furnace if a hazardous condition develops (improper flame or combustion). What size pipe is used as a header in a boiler operating at 100psi? 6 inches What device is used to measure flue gasses The Orsat Analyzer Which low water cut off does not have a mercury switch? The Submerged electrode type What is the btu output per lb of #4 fuel oil? 18 What substance is used for the electric transmission in an RTD? Platinum is used because of its stability at high temperatures How much air is needed for the combustion of pulverized coal; gas; oil? 50% for coal and 10-30% for gas & oil In old power boilers which type of feedwater regulators were not used? n(A) hydraulic n(B) float n(C) thermostatic expansion n(D) electronic ANSWER D electronic/electro-magnetic What is hard forming scale? Silica With hydroxide present and normal oxygen levels which chemical will cause problems? Chlorine The result from steel manufacturing and under pressure in boilers tends to cause buldging? A buldge is caused by ? A buldge is caused by overheating of the shell plates and it affects the entire thickness of the plate. A blister is caused by what ? Slag inclusion forming a lamination at the time the plate was rolled at the steel mill. A blister is a separation of the metal from the shell plate caused by impurities rolled into the shell plate when formed. With normal oxygen and low alkalinity. what is added to the boiler water? Neutralizing Amines Which chemical is used to combat scale? Combined phosphate treatment- sodium phosphate Other than sulfite what chemical is used to combat corrosion in boilers? Hydrazine What will neutralize acid? Alkali and Lime Soda What mechanical device is used to remove scale from firetubes? A tube rattler or vibrator What percentage of the pressure should a boiler have before you test the lever of a safety valve? 75% Where is internal corrosion most likely to occur on a vertical tube boiler? Water leg-Mud leg What are the minimum and maximum sizes permitted for blow down valves or connections? 3/4"minimum 2 ½ " maximum A boiler operating at a pressure of 65lbs. What is the smallest size feed and blow off connections if the safety valve is set at 90 psi? ½ " feed ¾ " blow off How often should water columns and water glass levels be checked on a high pressure boiler? (Once A Shift)nAt the beginning of each shift - beginning of the work effort What takes no actual action chemical part in combustion? Nitrogen How many ppm of EDTA are needed to tie up 1ppm of hardness? EDTA requires 10ppm of EDTA and 5 NTA to tie up each 1ppm hardness. On a package boiler; how many ways could cause fire puffs when it is started up? 6 ways 1-poor starting draft 2-incorrect firebox 3-wrong burner nozzle 4-lean fire 5- insufficient gas pilot or excessive gas pilot 6-water in the oil What is the grade of light domestic fuel oil ? Grade 1 ( Number 1 ) How often should you test the operating control? Annually How often should the testing and inspecting of the burner component? Annually A lead sulfite photocell is what type of flame sensor? Infrared light sensing What is the least amount of oxygen needed when a nitrogen blanket is used? 19% How should a boiler be prepared for inspection? Extinguish fire and allow boiler to cool slowly. Open the blow down and the drain; vent the boiler to the atmosphere Soot and ashes should be removed from all tubes; shell plates; heads; seams and every accessible external surface. The blow down should be shut if any other boiler feeds this line. Manhole - handhole plates and inspection plugs should be removed. All loose deposits of sludge or sediment should be washed out. The blow down should only be opened when it is certain that there is no pressure in the line and no one is inside the boiler. Any scale or oil deposits should be left for the water treatment specialist to see for analysis. A boiler properly prepared for inspection should be cool; dry and clean. It is advisable to attach a red tag marked "person in boiler" to the steam; blowdown; feed and fuel valves and also to the manhole plate whenever someone is inside a boiler. What function can a boiler operator contribute to boiler maintenance? A) maintain a safe reliable plant B) maintenance and efficient plant C) Inspection and logging of items that need to be corrected during the next maintenance period What are manholes and handholes on a boiler for? Examination or cleaning How do you protect a steam boiler? Safety valve How to you protect a pressure vessel? Pressure relief valve How do you protect a hot water boiler? Pressure relief valve What gages are on a steam boiler? Water gage glass and pressure gage Methods used to control the temperature of a superheater? Bypass damper - spray-type desuperheater - attemperator - condenser - tilting burner - flue gas recirculation What chemical would you use to prevent hard scale from forming in the boiler tubes? Disodium phosphate and trisodium phosphate What chemical compounds in water cause permanent hardness? Calcium sulfate and magnesium sulfate What factors must be taken into consideration when choosing a control for a boiler? 6 factors 1. Steam pressure 2. Furnace pressure and draft 3. air pressure and flow 4. feed water pressure and flow 5. Flue gas flow & composition 6. proper ignition & burner - flame control How many safety controls shut down a boiler when an unsafe condition occurs? CONTINUED......