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The component in which liquid vapor by absorbing heat is called? - ANS-Evaporator Select the best answer electrical grounding method? - ANS-Metal stake drive 8 foot into the ground. A _____ valve should be used for throttling purpose? - ANS-Globe What is the acceptable range for residual sodium sulfite in the boiler maintain? - ANS-30- What is the BTU content of a gallon of #4? - ANS-146, What does a zeolite water softener system use as a means of regeneration? - ANS-Brine
2026 update DC Third testing – actual
solution grade A+
What are the 4 steps for a Zeolite Rejuvenation water softener process? - ANS-Back wash Backwash, brine, rinse, service Where is medium temperature is liquid found? - ANS-Condenser Where is high temperature vapor found? - ANS-At the discharge of the compressor or condenser What stays are used to support the burner chamber in a scotch marine boiler? - ANS-Diagonal Stays What type of safety valve is this? - ANS-( Full) Crosby nozzle-type safety valve. Page 365 BOG What type of safety valve is this? - ANS-( Full) Crosby nozzle-type safety valve. Page 365 BOG Where do you found superheat reading? - ANS-Take suction line pressure Cross reference using a P/T Chart Get tail coil Temperature Subtract cross references temperature from tail coil temperature Result will be superheat
the cost of the chemical for a 30 days period? - ANS-Water In = Water Out Makeup + Condensate Return = Evaporator + Blow Down Average Evaporator Rate = 300 x 34.5 pph x .75% load = 7762, 50 pph 1 Month + .8( 7762.50 pph) = 7762.50 pph + 0500 m 1 Month + 6210 pph = 7762.50 pph + .0500 m -6210 - 1 Month = 1552.5 pph +. .9500 m = 1552.5 pph .9500m. 1Month = 1,634.21 pph Gallons per Month = 1634.21 / 8.33 x 24 x 30 = 141, 252.24 gallons per month Chemical needed = 141,252.24 gallon / 600 gallon = 235, 40 gallon Cost per month = 235, 40 gallon x 8.75 = $2,059.
During a 24 hours operation how often should you check the water level?
- ANS-Once per shift A 15 psi steam boiler produces 8000 pound of steam per hour. The Minimum pipe size for the pipe leaving the boiler is___12__inches. (Density is 0.037 lbs/ft3) Equation: - ANS-D = 12 (C/d/h /.7854) D = 12 (8000 / 0.037/60) = 3,603. D = .7854 / 5000ft = 3, D = 3.603.60 / 3,927 = 0. D = 0.957938963 * 12 D = 11.49 OR 12 "pipe The boiler steam line is 350 Feet long. During start-up the pipe is heated From 60 F to 350 F. The 350 F. The pipe wills expand__7.92__inches Due to the change in temperature Equation: - ANS-(T 1 - T2) x L x. (350 - 60) x 350 x. 290 x 350 x 12 x .0000065 = 7. A 12" pipe filled with water to a height of 250 feet will have a pressure of _________at the bottom of the pipe? Equation:
GPM = 12 x (4 x 4)
GPM = 192
GPM = 470.01 gpm What is the maximum pressure that a 15 x 9 x 10 duplex reciprocating pump Can develop when operating with 125-psi steam? - ANS-Pw = Ps x As Aw Pw = 125 x (15 x 15 x 0.7854) (9 x 9 x 0.7854) Pw = 22089.
Pw = 347.22 psi. During a 24 hours operation how often should you check the water level?
How often you checking the high limit switch? - ANS-Annually What is the recommended time for a complete external inspection of a boiler? - ANS-Once per shift What is the first thing to do when shutting down a boiler? - ANS-Turn of the fire A flow control should be blown down when? - ANS-Once per shift How often should you check the Low Water Fuel Cut off? - ANS-Once per shift Why is oil added to the refrigerant? - ANS-To lubrication of the compressor Keep refrigerant migrating Recycled and filtered refrigerant can be used where? - ANS-By the same owner in the same type of equipment Data printed on the equipment nameplate would include manufacturer, model, and serial number and________________? - ANS-Stamp of approval from commissioning authority
What is hard forming scale? - ANS-Silica Which chemicals are used to combat scale? - ANS-Combined Phosphate Treatment Which compound not heat produce? - ANS-Nitrogen What takes no actual action in combustion? - ANS-Nitrogen With hydroxide present and normal oxygen levels which chemical will cause problem? - ANS-Chlorine What mechanical device is used to remove scale from Fire Tubes? - ANS-A Tube Rattler or Vibrator is used (page 623) Who can make Adjustments or repairs on a Safety Valve? - ANS- Qualify person from Manufacturer or Representative What mechanical device is used to remove scale from water Tubes? - ANS-A Tube Turbine is used In a duct air handling system, space thermostat control building temperatures by? - ANS-Mixing the air from hot & cold duct in a mixing box serving the space
The removal of moisture from air using a cooling coil is called _________ dehumification? - ANS-Passive In a multi-zone air handler unit, the zone thermostat controls the zone temperature by? - ANS-Dampers that control the air flow from the hot & cold deck An air handler unit that has hot & cold air ducts connected to (molding boxes?) located in each building space is called a __________air handler unit? - ANS-Dual duct An air handler unit supplies a constant supply air temperature of 55 degree F to building spaces and includes a coil called _____air handler unit? - ANS-A terminal reheat An air handler unit that provides heating, cooling, ventilation, and air conditioning to more than one building or area and has its cooling & heating Coil in separate side-by side ducts is called a _______air handling unit? - ANS-Multi zone A duplex reciprocating pump runs at 75 rpm. The pump is a 12 x 5 x 12, Operating with 7% slip. What is the capacity of the pump? GPM = LANE 231 - ANS-GPM = 12 x (5 x 5 x 0.7854) x 75 x 2 x (1-0.07) 231
The expansion tank on a closed loop system should be located? - ANS- On the suction side of the pump What is the primary purpose of a crank case heater on a reciprocating chiller? - ANS-To prevent refrigeration migration What is meant by the percent of (skip, step, and slip) in a pump? - ANS- Percentage of flow compared minimum speed and full speed e. The difference in theoretical capacity compared to the actual capacity Which of the following types pump can be started with the discharge value closed? - ANS-Centrifugal The vertical distance from the center line of the pump up to top level of the supply tank is called? - ANS-Static suction head
- ANS-Where in a system is a foot valve value installed and what is its purpose? In a multi-zone air handling unit, the zone thermostat controls the zone temperature by? - ANS-Dampers that control the air flow from the hot & cold deck What is meant by a pump becoming steam bound? - ANS-When the static pressure at the suction of the pump falls below the vapor pressure corresponding to its temperature.
62.Which of the following is a positive displacement pump? - ANS- Reciprocating The heart of a refrigeration system is the _______? - ANS-Compressor Refrigerant flow into the evaporator is controlled by ___________? - ANS-A metering device What does the whistle on the top of the water column indicating? - ANS- High and low water condition A reciprocating compressor operating with refrigerant R-410 head pressure of 476 psi and a suction pressure of 118 psi. What is the compressor's compression ratio? - ANS-4 400 / 120 = 4:1 2nd choice The part of the refrigeration system that absorbs heat into the system is controlled by the ______? - ANS-Evaporator A replacement refrigerant for R-12 medium and high temperature refrigeration application is _____? - ANS-134 A The color for an R-134 a refrigerant cylinder is _______? - ANS-Light Blue
What do you do to attain complete combustion in a boiler? - ANS- Increase secondary air Air leaking into the inner and outer of the boiler, what will happen? - ANS-Decrease boiler efficiency By clicking on the exibit the picture is a display of (page 365 BOG)? - ANS-Full nozzle reaction type safety valve What controls the steam pressure and monitors the combustion air intake?
- ANS-Fuel, air, water What happens to the water in a boiler that is at 80% load of a sudden, the flame goes off? - ANS-Water will shrink and cause a low water condition (BOW page 289 point 46) What is installed between the boiler drum and the steam gauge to create a water seal protection for the gauge? - ANS-Siphon What is the replacement refrigerant for R-22? - ANS-R-410 A Which valves to the boiler is opened ______ and ______ during blow down? - ANS-By opening the Quick opening valve first and closing it Last. Page 403 BOG
How and why tube ends on a fire boiler are secure? - ANS-Tube ends are beaded to allow for greater expansion and control the tubes What is not an advantage of the economic type boiler over the conventional type boiler? - ANS-Allows greater flexibility expansion and contraction An accelerated circulation water tube in one characterized by? - ANS- Heated down comers What is platinum used in RTD (Resistive temperature Device)? - ANS- Because of its stability at high temperature In a HVAC system's, controlled by thermostat, the difference is the difference between The? - ANS-Set point and the temperature at which the switch turns the systems off What is the purpose of a suction accumulator? - ANS-It contains liquid refrigerant to allow evaporation prior to entering the compressor What must be submitted to the code official when field assembly of boilers is required? - ANS-Boiler inspection report A boiler has 2800 furnaces temperature and 600 stack temperatures reading. What is
What is the cause of high excess in a condensate return tank with temperature up to 20 Degrees above normal? - ANS-Steam traps are stuck open What is the cause of high excess in a condensate return tank with temperature up to 20 Degrees above normal? - ANS-Steam traps are stuck open Water inlet into a building is 100 psig, if no booster pumps are used. What will be the Pressure on the 10th floor, if the building is 10 feet per floor? - ANS-43.3 2.31 = 1 psi, 100 psi = 100/2.31 = 43.3 psi Where is the total hardness of a softener reading .5 grains? - ANS-( 17. x .5 = 8.6 ) How many BTUs are raise 2 lbs of water from 32F to 212F? - ANS- 360 btu 180 - 32 = 218 x 2 = 360btu A stoker that uses a feed RAM is a? - ANS-Underfeed stoker Water scales can be removed by boiling or raising water temperature is?
- ANS-Temporary Water scales can be removed by boiling or raising water temperature is?
- ANS-Temporary
What is the proper way of testing a safety valve? - ANS-Allow pressure to build up to 75% before lifting the test level What a safety valve discharge, it should relieve the boiler so that the pressure does not Exceed more than ______? - ANS-6% When conducting an evaporation test, the operator must secure what? - ANS-The feed water to the boiler What steam trap has one movable device that rises to allow steam through and resets On condensate? - ANS-Float trap 377 BOG 4th Ed What part in a refrigeration cycle discharges, high temperature pressure of vapor? - ANS-Compressor Discrete control when used for steam pressure is what type of control? - ANS-on/off stop/go What part in a refrigeration cycle discharges low pressure liquid? - ANS-Expansion valve How is a boiler hydrostatic test performed? - ANS-fill the boiler with 70 ºF of water and raise the pressure to 1.5 MAWP
