4BE3.5 U3 C5 Obj 1 EMH

<p>The temperature rises</p> Signup and view all the answers

<p>To reduce or stop the energy input</p> Signup and view all the answers

<p>Outlet water temperature</p> Signup and view all the answers

<p>Hot water supply temperature</p> Signup and view all the answers

<p>On-Off</p> Signup and view all the answers

<p>The burner generates too much heat for the load demand</p> Signup and view all the answers

<p>To start and shut off the burner</p> Signup and view all the answers

<p>Due to the furnace draft carrying heat away from the boiler and up the chimney</p> Signup and view all the answers

<p>To reduce heat losses</p> Signup and view all the answers

<p>On-off control</p> Signup and view all the answers

<p>The number of operating pressure controls used</p> Signup and view all the answers

<p>To control the low-fire burner</p> Signup and view all the answers

<p>The high-fire burner starts</p> Signup and view all the answers

<p>It reduces heat losses due to repeated purging</p> Signup and view all the answers

<p>To control the high-fire and low-fire burners</p> Signup and view all the answers

<p>It decreases</p> Signup and view all the answers

<p>The operating principle</p> Signup and view all the answers

<p>Boiler-firing circuits</p> Signup and view all the answers

<p>To shut off the burner in case of an operating control failure</p> Signup and view all the answers

<p>To maximize boiler operating efficiency</p> Signup and view all the answers

<p>The boiler pressure rises</p> Signup and view all the answers

<p>The boiler will over-pressurize and may explode</p> Signup and view all the answers

<p>To adjust to varying load demands</p> Signup and view all the answers

<p>ASME CSD-1</p> Signup and view all the answers

<p>The energy demand</p> Signup and view all the answers

<p>To directly actuate the combustion air damper</p> Signup and view all the answers

<p>To limit the firing rate during warm-up</p> Signup and view all the answers

<p>It provides the highest efficiency and closest set point adherence</p> Signup and view all the answers

<p>Three</p> Signup and view all the answers

<p>To position the modulating motor</p> Signup and view all the answers

<p>The firing rate drops to its minimum</p> Signup and view all the answers

<p>To cut off the burner above a certain pressure</p> Signup and view all the answers

<p>It reduces purge losses</p> Signup and view all the answers

<p>Three</p> Signup and view all the answers

<p>To activate a call for heat</p> Signup and view all the answers

<p>To prevent generation of steam pressure above the maximum allowable working pressure</p> Signup and view all the answers

<p>Pressure-actuated two-position single-pole, single-throw switches</p> Signup and view all the answers

<p>To position the modulating motor</p> Signup and view all the answers

<p>The boiler must be limited to low-fire until the boiler is sufficiently warm</p> Signup and view all the answers

<p>To enable modulation only when in RUN mode</p> Signup and view all the answers

<p>To shut off the fuel supply when the steam pressure reaches a preset maximum operating pressure</p> Signup and view all the answers

<p>Variable resistance temperature-actuated sensors</p> Signup and view all the answers

<p>At least one steam pressure control device that will shut off the fuel supply to each boiler</p> Signup and view all the answers

<p>To limit the firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>Two-position control devices do not modulate, while fully modulating control devices do</p> Signup and view all the answers

<p>480 kPa</p> Signup and view all the answers

<p>Single-pole, single-throw</p> Signup and view all the answers

<p>DN 8 (NPS ¼)</p> Signup and view all the answers

<p>At least one temperature-actuated control</p> Signup and view all the answers

<p>Increasing boiler pressure</p> Signup and view all the answers

<p>The mercury loses its lustre and may appear rusty</p> Signup and view all the answers

<p>The boiler shuts down and requires manual reset</p> Signup and view all the answers

<p>To shut off the fuel supply when the system water reaches a preset operating temperature</p> Signup and view all the answers

<p>The firing rate increases</p> Signup and view all the answers

<p>To shut off the burner when the operating pressure control fails</p> Signup and view all the answers

<p>The HTCO does not have a differential adjustment and has a manual reset button</p> Signup and view all the answers

<p>The HPCO has a manual reset button</p> Signup and view all the answers

<p>To interrupt the control signal</p> Signup and view all the answers

<p>90 kPa</p> Signup and view all the answers

<p>To activate the switch at the controller set point</p> Signup and view all the answers

<p>To operate the fuel valve</p> Signup and view all the answers

<p>To house the thermometer-sensing bulb</p> Signup and view all the answers

<p>To control the air and fuel flow separately</p> Signup and view all the answers

<p>To adjust the control differential</p> Signup and view all the answers

<p>115°C</p> Signup and view all the answers

<p>To fine-tune the combustion conditions</p> Signup and view all the answers

<p>The firing circuit is opened</p> Signup and view all the answers

<p>The burner remains shut off</p> Signup and view all the answers

<p>To adjust the inter-stage temperature differential</p> Signup and view all the answers

<p>The firing rate increases</p> Signup and view all the answers

<p>To avoid unnecessary lockouts</p> Signup and view all the answers

<p>To adjust the firing rate to match the boiler load</p> Signup and view all the answers

<p>To allow the firing rate to be kept at low-fire during warm-up periods</p> Signup and view all the answers

<p>To control how closely the boiler pressure tracks the set point</p> Signup and view all the answers

<p>The modulating motor drives to the closed position</p> Signup and view all the answers

<p>To balance the circuit and control the modulating motor</p> Signup and view all the answers

<p>To balance the circuit</p> Signup and view all the answers

<p>To provide feedback to the modulating controller</p> Signup and view all the answers

<p>To permit low-fire operation when the boiler is cold</p> Signup and view all the answers

<p>To provide the finest pressure control</p> Signup and view all the answers

<p>The control of the modulating motor is transferred to the manual flame control potentiometer</p> Signup and view all the answers

<p>To maximize boiler operating efficiency</p> Signup and view all the answers

<p>The boiler pressure falls</p> Signup and view all the answers

<p>To reduce the energy input when the pressure limit controls fail</p> Signup and view all the answers

<p>The boiler temperature falls</p> Signup and view all the answers

<p>The type of sensors used</p> Signup and view all the answers

<p>To manipulate the fuel flow</p> Signup and view all the answers

<p>It is more efficient</p> Signup and view all the answers

<p>To manipulate the fuel flow</p> Signup and view all the answers

<p>The boiler produces supersaturated hot water and over-pressurizes</p> Signup and view all the answers

<p>To maintain a steam pressure set point</p> Signup and view all the answers

<p>It is more efficient</p> Signup and view all the answers

<p>To maintain a hot water temperature set point</p> Signup and view all the answers

<p>To limit the firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>The firing rate decreases to low-fire</p> Signup and view all the answers

<p>Increased efficiency due to reduced purge losses</p> Signup and view all the answers

<p>To position the modulating motor in response to the error between the control set point and the boiler pressure</p> Signup and view all the answers

<p>To limit the firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>To shut off the burner when the boiler pressure exceeds a set point</p> Signup and view all the answers

<p>3</p> Signup and view all the answers

<p>To call for heat when the boiler pressure is below a set point</p> Signup and view all the answers

<p>Reduced purge losses</p> Signup and view all the answers

<p>To limit the firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>Because it minimizes the heat losses due to frequent cycling</p> Signup and view all the answers

<p>Because temperature and pressure swings are unacceptable in larger plants with more stringent pressure and temperature requirements</p> Signup and view all the answers

<p>To reduce the firing rate when the load demand is low</p> Signup and view all the answers

<p>The high-fire burner starts</p> Signup and view all the answers

<p>Multi-position control reduces heat losses caused by repeated purging</p> Signup and view all the answers

<p>It decreases</p> Signup and view all the answers

<p>To control the high-fire and low-fire burners</p> Signup and view all the answers

<p>Steam boilers use two operating pressure controls, while hot water boilers use two operating temperature controls</p> Signup and view all the answers

<p>Because they cycle more often, resulting in heat losses due to frequent purging</p> Signup and view all the answers

<p>It minimizes the heat losses due to frequent cycling</p> Signup and view all the answers

<p>To prevent steam from entering the control</p> Signup and view all the answers

<p>The electrical circuit for the combustion system opens</p> Signup and view all the answers

<p>Because they are prone to failure due to oxidation</p> Signup and view all the answers

<p>The HPCO has a manual reset button</p> Signup and view all the answers

<p>90 kPa</p> Signup and view all the answers

<p>To prevent excessive boiler pressure</p> Signup and view all the answers

<p>Both a and b</p> Signup and view all the answers

<p>SPST switch</p> Signup and view all the answers

<p>To control the combustion air damper and firing rate control valve in unison</p> Signup and view all the answers

<p>The firing circuit opens</p> Signup and view all the answers

<p>Because the operating pressure control has failed</p> Signup and view all the answers

<p>To fine-tune the combustion conditions</p> Signup and view all the answers

<p>The opposite sequence occurs, and the firing rate decreases</p> Signup and view all the answers

<p>To interrupt the control signal during warm-up or base loading</p> Signup and view all the answers

<p>Independent control of air and fuel flow</p> Signup and view all the answers

<p>To fine-tune the combustion conditions</p> Signup and view all the answers

<p>Pressure-actuated, single-pole, single-throw (SPST) switch</p> Signup and view all the answers

<p>To prevent generation of steam pressure above the maximum allowable working pressure</p> Signup and view all the answers

<p>Variable resistance temperature-actuated sensors</p> Signup and view all the answers

<p>It provides more precise control over the firing rate</p> Signup and view all the answers

<p>The boiler must be limited to low-fire until the boiler is sufficiently warm</p> Signup and view all the answers

<p>To limit the firing rate of the boiler to low-fire during startup</p> Signup and view all the answers

<p>To directly actuate the modulating motor that drives the combustion air damper and the firing rate control valve</p> Signup and view all the answers

<p>Variable resistance pressure-actuated sensors</p> Signup and view all the answers

<p>A two-position control device can only operate at two fixed firing rates, while a fully modulating control device can operate at any firing rate</p> Signup and view all the answers

<p>To shut off the fuel supply to the boiler when the steam pressure reaches a preset maximum operating pressure</p> Signup and view all the answers

<p>To shut off the burner when the operating temperature controls fail to stop the burner</p> Signup and view all the answers

<p>One temperature-actuated control to shut off the fuel supply when the system water reaches a preset operating temperature</p> Signup and view all the answers

<p>To activate the switch at the controller set point</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>To control the operating temperature of the boiler</p> Signup and view all the answers

<p>Whichever is greater between 5% lower and 480 kPa lower</p> Signup and view all the answers

<p>To measure the boiler water temperature</p> Signup and view all the answers

<p>To establish the cut-in and cut-out points</p> Signup and view all the answers

<p>It allows for easier mounting of the controller</p> Signup and view all the answers

<p>To prevent the water temperature from exceeding the maximum allowable water temperature</p> Signup and view all the answers

<p>To adjust the firing rate during warm-up periods</p> Signup and view all the answers

<p>To control how closely the boiler temperature tracks the set point</p> Signup and view all the answers

<p>The resistance of the slide wire controller changes, unbalancing the circuit</p> Signup and view all the answers

<p>To balance the circuit when the steam pressure or water temperature is at the set point</p> Signup and view all the answers

<p>To set the desired boiler pressure</p> Signup and view all the answers

<p>It provides more precise control over the firing rate</p> Signup and view all the answers

<p>To move to balance the circuit when the motor runs</p> Signup and view all the answers

<p>The control of the modulating motor is transferred to the manual flame control potentiometer</p> Signup and view all the answers

<p>To control how closely the boiler pressure tracks the set point</p> Signup and view all the answers

<p>To balance the circuit when the steam pressure or water temperature is at the set point</p> Signup and view all the answers

<p>To maximize boiler operating efficiency</p> Signup and view all the answers

<p>The boiler pressure falls</p> Signup and view all the answers

<p>ASME CSD-1</p> Signup and view all the answers

<p>The boiler explodes</p> Signup and view all the answers

<p>To manipulate the fuel flow and airflow</p> Signup and view all the answers

<p>The temperature would fall</p> Signup and view all the answers

<p>Varying load demands</p> Signup and view all the answers

<p>The energy demand</p> Signup and view all the answers

<p>The measured variable</p> Signup and view all the answers

<p>To prevent over-pressurization</p> Signup and view all the answers

<p>Shut off the burner to prevent unsafe operating conditions</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>Boiler-firing circuits</p> Signup and view all the answers

<p>To change the firing rate as required to maintain a steam pressure set point</p> Signup and view all the answers

<p>The number of firing rates</p> Signup and view all the answers

<p>It equals the average heat requirements of the process</p> Signup and view all the answers

<p>To reduce or stop the energy input</p> Signup and view all the answers

<p>It is more energy efficient</p> Signup and view all the answers

<p>Significant loss of heat from the boiler due to frequent cycling</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>The high-fire burner starts</p> Signup and view all the answers

<p>To provide low heat output</p> Signup and view all the answers

<p>It decreases</p> Signup and view all the answers

<p>Finer control of boiler steam pressure or temperature</p> Signup and view all the answers

<p>To control high and low firing rates</p> Signup and view all the answers

<p>Because of temperature and pressure swings</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>The low-fire burner starts</p> Signup and view all the answers

<p>To actuate the modulating motor that drives the combustion air damper and the firing rate control valve</p> Signup and view all the answers

<p>To prevent generation of steam pressure above the maximum allowable working pressure</p> Signup and view all the answers

<p>The boiler is limited to low-fire until the boiler is sufficiently warm</p> Signup and view all the answers

<p>To limit the firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>Pressure-actuated sensors</p> Signup and view all the answers

<p>To maintain the steam pressure within a desired range</p> Signup and view all the answers

<p>At least one steam pressure control device that will shut off the fuel supply to each boiler</p> Signup and view all the answers

<p>A two-position control device has two positions, while a fully modulating control device has multiple positions</p> Signup and view all the answers

<p>The firing rate is adjusted to low-fire</p> Signup and view all the answers

<p>It is more efficient and provides better combustion efficiency</p> Signup and view all the answers

<p>To regulate the air-to-fuel ratio</p> Signup and view all the answers

<p>The burner turns off</p> Signup and view all the answers

<p>To limit the firing rate to low fire during warm-up</p> Signup and view all the answers

<p>Reduced purge losses</p> Signup and view all the answers

<p>To shut off the burner during high-pressure events</p> Signup and view all the answers

<p>To activate a call for heat</p> Signup and view all the answers

<p>To position the modulating motor</p> Signup and view all the answers

<p>To provide a last line of defense before the safety valve operates</p> Signup and view all the answers

<p>The modulating motor places the air and fuel in high-fire</p> Signup and view all the answers

<p>Reduced purge losses</p> Signup and view all the answers

<p>DN 8 (NPS ¼)</p> Signup and view all the answers

<p>To control the firing rate</p> Signup and view all the answers

<p>The mercury loses its lustre and may appear rusty</p> Signup and view all the answers

<p>To require operator intervention after a trip condition</p> Signup and view all the answers

<p>90 kPa or less</p> Signup and view all the answers

<p>To prevent steam from entering the control</p> Signup and view all the answers

<p>Mercury switches are no longer manufactured, while mechanical switches are used instead</p> Signup and view all the answers

<p>To adjust the cut-in and cut-out points of the control</p> Signup and view all the answers

<p>At least 10% lower than the safety valve setting, or 50 kPa lower</p> Signup and view all the answers

<p>To permit low-fire operation during warm-up periods</p> Signup and view all the answers

<p>To balance the circuit and stop the modulating motor</p> Signup and view all the answers

<p>The burner shuts off, and the SSOVs close</p> Signup and view all the answers

<p>The modulating motor drives the damper to the closed position</p> Signup and view all the answers

<p>To provide feedback to the modulating controller</p> Signup and view all the answers

<p>It is more efficient than on-off control</p> Signup and view all the answers

<p>To shut down the boiler in case of an emergency</p> Signup and view all the answers

<p>To operate the potentiometer</p> Signup and view all the answers

<p>The modulating motor drives the damper to the open position</p> Signup and view all the answers

<p>To enable the modulating controller when the boiler is in RUN mode</p> Signup and view all the answers

<p>To interrupt the control signal, so that the boiler can be kept at low-fire for warm up or base loaded</p> Signup and view all the answers

<p>Using two modulating motors that receive the same signal from a single master pressure or temperature controller</p> Signup and view all the answers

<p>To fine-tune the combustion conditions</p> Signup and view all the answers

<p>A single modulating motor that operates both the combustion air damper and the firing rate control valve, in unison</p> Signup and view all the answers

<p>The opposite sequence occurs, increasing the fuel flow and air flow to restore the pressure or temperature to the set point</p> Signup and view all the answers

<p>To provide a single signal to the modulating motors that control the air and fuel flow</p> Signup and view all the answers

<p>5% lower or 480 kPa lower</p> Signup and view all the answers

<p>To prevent the water temperature from exceeding the maximum allowable water temperature</p> Signup and view all the answers

<p>The HTCO has a manual reset button</p> Signup and view all the answers

<p>Each boiler must have at least one temperature-actuated control</p> Signup and view all the answers

<p>To activate the switch at the controller set point</p> Signup and view all the answers

<p>To shut off the fuel supply when the system water reaches a preset operating temperature</p> Signup and view all the answers

<p>Each limit and operating control must have its own sensing element and operating switch</p> Signup and view all the answers

<p>To adjust the inter-stage temperature differential</p> Signup and view all the answers

<p>To prevent the water temperature from exceeding the maximum allowable water temperature</p> Signup and view all the answers

<p>The HTCO must be set higher than the operating temperature control</p> Signup and view all the answers

<p>Two-position control = Either fully on or fully off Multi-position control = Can have multiple firing rates Fully modulating control = Can adjust firing rate to match demand On-off control = Can only be fully on or fully off</p> Signup and view all the answers

<p>High limit control = Shuts off the burner to prevent unsafe operating conditions Sensing element = Measures the process variable Controller = Adjusts the firing rate based on the measured variable Final control element = Executes the control action</p> Signup and view all the answers

<p>Greater heat energy entering the boiler than required = Pressure rises Less heat energy entering the boiler than required = Pressure falls Energy output equals energy demand = Pressure remains constant Excessive firing rate = Over-pressurization</p> Signup and view all the answers

<p>Two-position control = Significant loss of heat Fully modulating control = Maximum boiler operating efficiency Multi-position control = Multiple firing rates On-off control = Either fully on or fully off</p> Signup and view all the answers

<p>Resistance slide-wire control = Adjusts the firing rate based on pressure Programming controller = Adjusts the firing rate based on a schedule Manual firing rate limit switch = Limits the firing rate for safety High-pressure cut-off control = Shuts off the burner to prevent over-pressurization</p> Signup and view all the answers

<p>ASME CSD-1 = Code for automatically fired boilers CW-310 = Part of ASME CSD-1 for automatically fired steam boilers NEC = Code for electrical installations OSHA = Code for workplace safety</p> Signup and view all the answers

<p>Fully modulating control = Maximum boiler operating efficiency Multi-position control = Improved boiler operating efficiency On-off control = Simple and low-cost Two-position control = Less expensive than fully modulating control</p> Signup and view all the answers

<p>Operating pressure control = Maintains the desired operating pressure High-pressure cut-off control = Shuts off the burner to prevent over-pressurization Low-fire control = Limits the firing rate to prevent over-pressurization High-limit control = Shuts off the burner to prevent unsafe operating conditions</p> Signup and view all the answers

<p>On-Off Control = Non-modulating, two-position control Multi-Position Control = Permits finer control of boiler steam pressure or temperature Two-Position Control = Reduces heat losses caused by repeated purging Fully Modulating Control = Used in smaller capacity boilers</p> Signup and view all the answers

<p>Low-Pressure Steam Boiler = Cycles based on pressure Hot Water Boiler = Cycles based on temperature On-Off Boiler = Operates continuously for greater efficiency Multi-Position Boiler = Has a single operating pressure control</p> Signup and view all the answers

<p>On-Off Firing Rate Control = One operating pressure control (pressuretrol) Multi-Position Firing Rate Control = Two operating pressure controls Fully Modulating Firing Rate Control = Resistance slide-wire control Two-Position Firing Rate Control = Manual firing rate limit switch</p> Signup and view all the answers

<p>Low Load = Boiler cycles more often High Load = Boiler cycles less frequently Low Pressure = High-fire burner starts High Pressure = Low-fire burner shuts off</p> Signup and view all the answers

<p>On-Off Control = Less complex controls Multi-Position Control = Reduces heat losses caused by repeated purging Two-Position Control = Used in smaller capacity boilers Fully Modulating Control = Greater efficiency and plant efficiency</p> Signup and view all the answers

<p>On-Off Firing Rate Control = Cycles on and off based on load demand Multi-Position Firing Rate Control = Permits finer control of boiler steam pressure or temperature Two-Position Firing Rate Control = Has a single operating pressure control Fully Modulating Firing Rate Control = Operates continuously for greater efficiency</p> Signup and view all the answers

<p>Pressuretrol = Operates as a pressure-operated switch SSOV = Shuts, opens at a low-fire setting, or opens at a high-fire setting Aquastat = Controls high and low firing rates Burner = Produces heat energy</p> Signup and view all the answers

<p>Frequent Cycling = Reduces boiler efficiency Continuous Operation = Improves boiler efficiency Low Load = Increases cycling rates High Load = Reduces cycling rates</p> Signup and view all the answers

<p>On-Off Control = Used in smaller capacity boilers Multi-Position Control = Used in larger capacity boilers Two-Position Control = Used in hot water boilers Fully Modulating Control = Used in steam boilers</p> Signup and view all the answers

<p>On-Off Firing Rate Control = Non-modulating, two-position control Multi-Position Firing Rate Control = Permits finer control of boiler steam pressure or temperature Two-Position Firing Rate Control = Reduces heat losses caused by repeated purging Fully Modulating Firing Rate Control = Operates continuously for greater efficiency</p> Signup and view all the answers

<p>Operating pressure control = Activates a call for heat Resistance slide-wire pressure control = Positions the modulating motor High-pressure cut-off control = Cuts off the burner when the boiler pressure reaches a set point Manual firing rate limit switch = Limits the firing rate to low fire during warm-up</p> Signup and view all the answers

<p>Smaller capacity boilers = On-off control Larger capacity boilers = Fully modulating firing rate control Hot water boilers = Multi-position control Steam boilers = Two-position firing rate control</p> Signup and view all the answers

<p>High-fire control = Directly actuates the modulating motor that drives the combustion air damper Low-fire control = Limits the firing rate to low fire during warm-up Pressuretrol = Operates the burner between high and low firing rates Modulating motor = Positions the combustion air damper and the firing rate control valve</p> Signup and view all the answers

<p>Boiler pressure below 50 kPa = Burner turns on Boiler pressure above 70 kPa = Burner turns off Boiler pressure between 50 kPa and 70 kPa = Firing rate is modulated Boiler pressure above 55 kPa = Firing rate gradually drops to its minimum</p> Signup and view all the answers

<p>Fully modulating firing rate control = High-efficiency boilers Two-position firing rate control = Small capacity boilers Multi-position firing rate control = Medium capacity boilers On-off control = Low-efficiency boilers</p> Signup and view all the answers

<p>Modulating motor = Positions the combustion air damper and the firing rate control valve Resistance slide-wire pressure control = Determines the firing rate Operating pressure control = Activates the burner High-pressure cut-off control = Limits the boiler pressure</p> Signup and view all the answers

<p>Heat input exceeds load demand = Boiler pressure continues to rise Boiler pressure below 55 kPa = Firing rate increases Boiler pressure above 65 kPa = Firing rate gradually drops to its minimum Boiler pressure above 70 kPa = Burner turns off</p> Signup and view all the answers

<p>Steam boilers = Three pressure controls Hot water boilers = Three temperature controls Small capacity boilers = Two pressure controls Large capacity boilers = Four pressure controls</p> Signup and view all the answers

<p>Fully modulating firing rate control = Highest efficiency and closest set point adherence Two-position firing rate control = Simple and low-cost Multi-position firing rate control = Better efficiency than on-off control On-off control = Lowest cost</p> Signup and view all the answers

<p>Steam Boiler Control System = Steam pressure Hot Water Boiler Control System = Outlet water temperature Multi-position Control System = Flow rate Two-position Control System = Energy demand</p> Signup and view all the answers

<p>Two-position Control = Cycling on and off Multi-position Control = Firing at intermediate rates Fully Modulating Control = Cycling on and off On-Off Control = Firing at maximum heat rating</p> Signup and view all the answers

<p>Operating pressure control = Cut-in at 50 kPa and cut-out at 70 kPa High-pressure cut-off control = Cut-out at 70 kPa Resistance slide-wire pressure control = Positions the modulating motor Manual firing rate limit switch = Limits the firing rate to low fire during warm-up</p> Signup and view all the answers

<p>Steam Boilers = Safety valves Hot Water Boilers = Temperature limit controls Packaged Boilers = Pressure relief valves Industrial Boilers = High-pressure cut-off controls</p> Signup and view all the answers

<p>Combustion air dampers = Regulating airflow Firing rate control valve = Controlling fuel flow High-fire control = Limiting excessive heat input Low-fire control = Regulating airflow</p> Signup and view all the answers

<p>Steam Boiler Control System = Steam pressure Hot Water Boiler Control System = Hot water supply temperature Multi-position Control System = Flow rate Two-position Control System = Energy demand</p> Signup and view all the answers

<p>Steam Boiler Control System = Combustion air dampers and firing rate control valve Hot Water Boiler Control System = Fuel flow control valve Multi-position Control System = Airflow damper Two-position Control System = Fuel pump</p> Signup and view all the answers

<p>Steam Boiler Control System = Fuel flow and airflow Hot Water Boiler Control System = Fuel flow and airflow Multi-position Control System = Fuel flow only Two-position Control System = Airflow only</p> Signup and view all the answers

<p>Two-position Control = Simple and low-cost Multi-position Control = More efficient and precise Fully Modulating Control = Improved plant efficiency On-Off Control = Reliable and easy to maintain</p> Signup and view all the answers

<p>Steam Boiler Control System = Pressure-sensitive sensors Hot Water Boiler Control System = Temperature-sensitive sensors Multi-position Control System = Flow rate sensors Two-position Control System = Energy demand sensors</p> Signup and view all the answers

<p>Steam Boiler Control System = Maintaining steam pressure set point Hot Water Boiler Control System = Maintaining hot water supply temperature set point Multi-position Control System = Matching energy output to demand Two-position Control System = Regulating energy input</p> Signup and view all the answers

<p>Two-position pressure control device = Operating pressure control, high and low firing controls, and high-pressure cut-offs Variable resistance pressure-actuated sensor = Controls the firing rate of fully modulating burners Modulating motor = Positions fuel valves and combustion air dampers Pressure-actuated single-pole, single-throw switch = Sensing element and operating switch</p> Signup and view all the answers

<p>Two-position control devices = On-off boilers Multi-position control devices = Hot water boilers Fully modulating firing rate control devices = Steam boilers High-pressure cut-off control devices = Power burners</p> Signup and view all the answers

<p>At least one steam pressure control device = CW-310 a) High steam pressure limit control = CW-310 b) Manual reset = CW-310 c) No shutoff valve in the steam pressure connection = CW-310 d)</p> Signup and view all the answers

<p>Two-position boilers = On-off control Multi-position boilers = Modulating control Fully modulating boilers = Variable resistance control Power burners = Linkage and cam control</p> Signup and view all the answers

<p>Programming controller = Places boiler in AUTO or HIGH mode Modulating motor = Positions fuel valves and combustion air dampers Resistance slide-wire pressure control = Positions modulating motor Manual firing rate limit switch = Limits firing rate to low-fire during warm-up</p> Signup and view all the answers

<p>Pressure-actuated sensors = Steam boilers Temperature-actuated sensors = Hot water boilers Variable resistance sensors = Fully modulating burners Sensing elements = Operating pressure controls</p> Signup and view all the answers

<p>Improved combustion efficiency = Maximum heat output Reduced thermal stress = Increased boiler lifespan Increased plant efficiency = Optimized energy output Limiting firing rate to low-fire during warm-up = Prevents uneven thermal expansion</p> Signup and view all the answers

<p>Prevents generation of steam pressure above maximum allowable working pressure = CW-310 b) Causes safety shutdown and lockout when activated = CW-310 c) Requires manual reset = CW-310 d) Indicates when it is activated = CW-310 a)</p> Signup and view all the answers

<p>Operating pressure control = Between the boiler and steam pressure connection High-pressure cut-off control = After the operating pressure control Low-fire control = Before the operating pressure control Modulating motor = After the resistance slide-wire pressure control</p> Signup and view all the answers

<p>Two-position boilers = Two-position control devices Multi-position boilers = Multi-position control devices Fully modulating boilers = Fully modulating firing rate control devices Power burners = Variable resistance pressure-actuated sensors</p> Signup and view all the answers

<p>Modulating motor = Adjusts fuel flow for optimum combustion efficiency Jackshaft = Operates combustion air damper and firing rate control valve Fuel cam = Fine-tunes combustion conditions Master pressure controller = Provides signal to modulating motor</p> Signup and view all the answers

<p>Two-position control = Burner is either on or off Multi-position control = Burner firing rate can be adjusted Fully modulating control = Continuous adjustment of fuel flow MAN-AUTO control = Allows manual interruption of control signal</p> Signup and view all the answers

<p>Steam pressure falls = Fuel flow increases Steam pressure rises = Fuel flow decreases Boiler is base loaded = Firing rate is adjusted for low-fire Boiler is warm up = Firing rate is adjusted for low-fire</p> Signup and view all the answers

<p>Crank arms = Operate combustion air damper and firing rate control valve Cam = Fine-tunes combustion conditions Master pressure controller = Provides signal to modulating motor Jackshaft = Converts rotary motion to linear motion</p> Signup and view all the answers

<p>Two-position control = Simple and cost-effective Multi-position control = Improves efficiency and reduces wear Fully modulating control = Provides precise control and flexibility MAN-AUTO control = Allows manual override for safety</p> Signup and view all the answers

<p>Modulating motor = Receives signal from master pressure controller Fuel cam = Adjusts fuel flow for combustion conditions Crank arms = Operate combustion air damper and firing rate control valve Jackshaft = Converts rotary motion to linear motion</p> Signup and view all the answers

<p>Mercury Switch = Relies on a bellows and a pressure adjustment spring to operate Mechanical Switch = Uses a pressure capsule to move levers and activate the switch High Pressure Cut-Off = Has a manual reset button and no differential adjustment Operating Pressure Control = Has a differential adjustment and is used for low-pressure boiler service</p> Signup and view all the answers

<p>Steam Heating Boilers = Not to exceed 90 kPa Steam Power Boilers (Up to 2100 kPa MAWP) = At least 10% lower than the safety valve setting, or 50 kPa lower than the safety valve setting, whichever is greater Steam Power Boilers (Over 2100 kPa to 6890 kPa) = At least 7% lower than the safety valve setting, or 200 kPa lower than the safety valve setting, whichever is greater Hot Water Boilers = No specific recommendation provided</p> Signup and view all the answers

<p>Differential = The difference between the cut-out and cut-in points Process Variable = Not mentioned in the provided content Control Differential = Determines the difference between the cut-out and cut-in points SPST Switch = Single Pole Single Throw switch</p> Signup and view all the answers

<p>Mercury Switch = Tilting the mercury switch causes the mercury to flow to the opposite end of the tube, opening or closing the electrical circuit Mechanical Switch = Moving levers and activating the switch according to the spring tension on the pressure adjustment High Pressure Cut-Off = Not mentioned in the provided content Operating Pressure Control = Increasing boiler pressure causes the bellows to expand and tilt the mercury switch</p> Signup and view all the answers

<p>Two-Position Control = Relies on a mercury switch or mechanical switch to operate Fully Modulating Firing Rate Control = Uses a resistance slide-wire control to modulate the firing rate Multi-Position Control = Has a low-fire control and multiple operating pressure controls On-Off Control = Not mentioned in the provided content</p> Signup and view all the answers

<p>Siphon = Protects the pressure control device from steam entering the control Mercury Switch = Operates the electrical circuit for the combustion system Pressure Capsule = Moves levers and activates the switch Bellows = Expands and tilts the mercury switch</p> Signup and view all the answers

<p>Mercury Switch = Prone to failure due to small cracks in the glass allowing oxygen to enter Mechanical Switch = Not mentioned in the provided content High Pressure Cut-Off = Requires manual reset after activation Operating Pressure Control = Has a differential adjustment that may require resetting</p> Signup and view all the answers

<p>Steam Heating Boilers = Not mentioned in the provided content Steam Power Boilers = Requires operator intervention to reset the high-pressure cut-off after activation Hot Water Boilers = Not mentioned in the provided content Multi-Position Firing Rate Control = Requires operator intervention to reset the operating pressure control after activation</p> Signup and view all the answers

<p>High Pressure Cut-Off = Set higher than the operating pressure control and the low-fire control Operating Pressure Control = Set lower than the high-pressure cut-off Low-Fire Control = Set lower than the operating pressure control Multi-Position Firing Rate Control = Has multiple operating pressure controls with different settings</p> Signup and view all the answers

<p>Mercury Switch = Fails to close or open the switch contacts due to oxidation of the mercury Mechanical Switch = Not mentioned in the provided content High Pressure Cut-Off = Locks in the open position and requires manual reset Operating Pressure Control = Fails to stop the burner due to faulty differential adjustment</p> Signup and view all the answers

<p>HPCO = High Pressure Cut-Off HTCO = High Temperature Cutoff Operating Temperature Control = Combines a filled system thermometer with a bellows-operated SPST switch ASME CSD-1 Part CW-410 = Requirements for Temperature Controls for Hot-Water Heating and Supply Boilers</p> Signup and view all the answers

<p>High Temperature Cutoff = Shuts off the burner when the operating temperature controls fail to stop the burner Operating Temperature Control = Combines a filled system thermometer with a bellows-operated SPST switch High-Low Fire Control = Used for hi-low fired boilers to satisfy the requirement for two operating temperature controls High Pressure Cut-Off = Prevents the water temperature from exceeding the maximum allowable water temperature</p> Signup and view all the answers

<p>Two-Position Temperature Control = A temperature-actuated, single-pole, single-throw (SPST) switch Multi-Position Firing Rate Control = Used in larger capacity boilers for more precise control High Temperature Limit Control = Requires manual reset and indicates when it is activated Operating Cycle = The process of the boiler firing and shutting off repeatedly</p> Signup and view all the answers

<p>High Temperature Cutoff = Has a manual reset button and locks in the open position when activated Operating Temperature Control = Has a differential adjustment and does not have a manual reset High Pressure Cut-Off = Prevents the water temperature from exceeding the maximum allowable water temperature High-Low Fire Control = Used in hi-low fired boilers and has two SPST switches operated by the same thermal element</p> Signup and view all the answers

<p>ASME CSD-1 Part CW-410 = Requirements for Temperature Controls for Hot-Water Heating and Supply Boilers HPCO Setting = Should be at least 5% lower than the setting of the safety valve, or 480 kPa lower, whichever is greater HTCO Setting = Factory set to 121°C, and has a fixed 11°C differential Operating Temperature Control = Used to shut off the fuel supply when the system water reaches a preset operating temperature</p> Signup and view all the answers

<p>High Temperature Limit Control = Prevents the water temperature from exceeding the maximum allowable water temperature High Pressure Cut-Off = Shuts off the burner when the operating temperature controls fail to stop the burner Operating Temperature Control = Combines a filled system thermometer with a bellows-operated SPST switch High-Low Fire Control = Used in hi-low fired boilers to satisfy the requirement for two operating temperature controls</p> Signup and view all the answers

<p>Two-Position Control = A temperature-actuated, single-pole, single-throw (SPST) switch Multi-Position Firing Rate Control = Used in larger capacity boilers for more precise control High Temperature Cutoff = Requires manual reset and indicates when it is activated Operating Cycle = The process of the boiler firing and shutting off repeatedly</p> Signup and view all the answers

<p>High Temperature Limit Control = Requires manual reset and indicates when it is activated Operating Temperature Control = Has a differential adjustment and does not have a manual reset High Pressure Cut-Off = Prevents the water temperature from exceeding the maximum allowable water temperature High-Low Fire Control = Used in hi-low fired boilers and has two SPST switches operated by the same thermal element</p> Signup and view all the answers

<p>ASME CSD-1 Part CW-410 = Requirements for Temperature Controls for Hot-Water Heating and Supply Boilers HPCO Setting = Should be at least 5% lower than the setting of the safety valve, or 480 kPa lower, whichever is greater HTCO Setting = Factory set to 121°C, and has a fixed 11°C differential Operating Temperature Control = Used to shut off the fuel supply when the system water reaches a preset operating temperature</p> Signup and view all the answers

<p>High Temperature Limit Control = Prevents the water temperature from exceeding the maximum allowable water temperature High Pressure Cut-Off = Shuts off the burner when the operating temperature controls fail to stop the burner Operating Temperature Control = Combines a filled system thermometer with a bellows-operated SPST switch High-Low Fire Control = Used in hi-low fired boilers to satisfy the requirement for two operating temperature controls</p> Signup and view all the answers

<p>Steam boilers = Modulating temperature control Hot water boilers = Modulating pressure control</p> Signup and view all the answers

<p>Manual flame control potentiometer = Allows low-fire operation during warm-up periods Bridge circuit = Positions the combustion air damper and the firing rate control valve Balancing relay = Unbalances the circuit to drive the modulating motor Feedback potentiometer = Operates the potentiometer in the form of a resistance slide wire</p> Signup and view all the answers

<p>On-off control = Has a single set point Modulating control = Has a proportional range setting Two-position control = Has a low-fire control Multi-position control = Has a single set point</p> Signup and view all the answers

<p>Modulating motor = Positions the combustion air damper and the firing rate control valve Resistance slide wire = Operates a potentiometer to adjust the firing rate High-pressure cut-off = Shuts off the boiler when the pressure exceeds a set point Manual-AUTOMATIC switch = Transfers control of the modulating motor to the manual flame control potentiometer</p> Signup and view all the answers

<p>Modulating pressure control = Steam boilers with fully modulating burners Modulating temperature control = Hot water boilers with fully modulating burners On-off control = Smaller capacity boilers Multi-position control = Steam boilers with fully modulating burners</p> Signup and view all the answers

<p>Set point = Determines the desired boiler pressure or temperature Differential setting = Controls how closely the boiler pressure tracks the set point Proportional range setting = Determines the desired boiler pressure or temperature MIN setting = Tracks the set point the closest, to provide the finest pressure control</p> Signup and view all the answers

<p>Programming controller = Enables the modulating controller when in RUN Manual flame control potentiometer = Allows the firing rate to be kept at low-fire during warm-up periods Modulating controller = Adjusts the firing rate to match the boiler load Balancing relay = Unbalances the circuit to drive the modulating motor</p> Signup and view all the answers

<p>Steam boiler warm-up = Manual flame control potentiometer Hot water boiler operation = Modulating temperature control Steam boiler operation = Modulating pressure control Hot water boiler warm-up = Modulating motor</p> Signup and view all the answers

<p>Modulating control = Continuously adjusts the firing rate to match the boiler load On-off control = Has a single set point Two-position control = Has a low-fire control Multi-position control = Has a proportional range setting</p> Signup and view all the answers

<p>Modulating motor = Adjusts the firing rate to match the boiler load Feedback potentiometer = Moves to balance the circuit Balancing relay = Causes the modulating motor to drive to the closed position Resistance slide wire = Operates a potentiometer to adjust the firing rate</p> Signup and view all the answers