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81 Cards in this Set
- Front
- Back
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Low temp boilers max temperature? |
250F (120c) |
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Max pressure of low temp boilers? |
1100kPa (160psig) |
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Max pressure on conventional cast-iron boilers? |
207 kPa (30 psig) |
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How are low temp boilers usually rated? |
In BTU/hr or EDR |
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What does EDR mean? |
Equivalent direct radiation (1 hot water EDR = 150BTU/Hr) (1 steam EDR = 240BTU/Hr) |
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What ASME section covers low temp boilers? |
IV |
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How are high temp boilers usually rated? |
MBH or BHP |
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What does MBH stand for? |
Thousands of BTU per hour Example: 6MBH = 6000 BTU |
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What does BHP stand for and what is it’s equivalent BTU? |
boiler horse power 1 BHP = 33.475 BTU |
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Auto air vents need how much pressure at the inlet? |
4psi |
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What is Net rating equivalent too? |
75% of the gross rating |
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How much additional pressure do you need in a low temp boiler to raise the boiling point to 250F? |
15 PSI |
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Low mass boilers need what to start? |
A steady flow of water through the heat exchanger |
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What do high mass boilers need to start? |
Needs water, but does not need flow |
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What holds sections of cast together in a boiler to allow water to pass through each section? |
Push nipple |
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What is a push nipple? |
Non-threaded space nipple that holds cast sections together |
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What draws together the cast sections? |
Tie rods |
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How do you calculate boiler efficiency? (Not net rating) |
(Gross output in BTUH / Input in BTUH) x 100 = % efficiency |
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What 2 ways do you lose BTUs inside the boiler? |
Stack losses Jacket losses |
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What 2 ways do you lose BTUs between the boiler and the Fin? |
Transmission losses Pick up load |
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After calculating input - stack/jacket losses, what is your outcome called? |
Gross output |
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After calculating your gross output - transmission losses/ pickup load, what is your outcome called? |
Net rating |
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Using figure 49 on page 53 in ILM 060202a, what is A? |
Flow switch |
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Using figure 49 on page 53 in ILM 060202a, what is B? |
Circulator |
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Using figure 49 on page 53 in ILM 060202a, what is C? |
Auto air vent |
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Using figure 49 on page 53 in ILM 060202a, what is D? |
Line scoop |
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Using figure 49 on page 53 in ILM 060202a, what is E? |
Diaphragm Expansion Tank |
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Using figure 49 on page 53 in ILM 060202a, what is F? |
Pressure Reducing Valve |
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Using figure 49 on page 53 in ILM 060202a, what is G? |
Flow Control Valve |
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Using figure 49 on page 53 in ILM 060202a, what is H? |
Back flow device |
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Using figure 49 on page 53 in ILM 060202a, what is I? |
Drain valve |
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Using figure 49 on page 53 in ILM 060202a, what is J? |
High limit control and operating control |
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Using figure 49 on page 53 in ILM 060202a, what is K? |
Combination gauge |
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Using figure 49 on page 53 in ILM 060202a, what is L? |
Safety Relief Valve |
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Using figure 49 on page 53 in ILM 060202a, what is M? |
Low water cut off |
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Using figure 49 on page 53 in ILM 060202a, what is N? |
Temperature gauge |
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What are the types of low water cut offs? |
Float type and probe type |
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What are you looking for on a safety relief valve to insure it is okay to use? |
V or HV symbol |
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What is a horizontal section boiler also known as? |
Pancake boiler |
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What is a horizontal section boiler also known as? |
Pancake boiler |
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What is the efficiency rate of a condensing boiler? |
90% or greater |
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What is a horizontal section boiler also known as? |
Pancake boiler |
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Boiler fittings are for which type of boiler? |
High mass boiler. |
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A line scoop needs smooth flow to allow air to release. How long of straight pipe do you need on either side of a line scoop? |
5 pipe diameters |
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What is an advantage of a microbubble resorber over a line scoop? |
Microbubble resorber does not need smooth flow, can be used in tighter piping systems where 5 pipe diameters can’t be achieved on both sides of scoop. |
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What 2 things can be tied into a line scoop? |
An auto air vent or a cushion tank |
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Where do you install a pressure reducing valve? |
On the domestic water line, between the boiler and compression tank |
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What are the 3 types of tanks used for fluid expansion? |
Open expansion tank Cushion tank Diaphragm tank |
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Where does an open expansion tank get installed? |
3 feet above the highest pipe |
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What is the temperature limit on an open expansion tank? |
180F |
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Where can you install a cushion tank? |
Above the boiler, piped to the line scoop. |
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What pressure is a cushion tank under? |
15psi |
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What is the efficiency rate of a condensing boiler? |
90% or greater |
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Where can a diaphragm tank be installed? |
Anywhere around the boiler |
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What pressure is the diaphragm tank under? |
Whatever pressure matches the system |
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What must be installed to the line scoop if a diaphragm tank is being used? |
An auto air vent. |
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What are the two types of circulators? |
Conventional Wet rotor |
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How is an conventional circulator cooled and lubricated? |
Air cooled, lubricated by oil/grease |
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How is a wet rotor circulator cooled and lubricated? |
Cooled and lubricated by heating system fluid |
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What do both circulators utilize to move water? |
An impeller |
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What is the housing for the impeller on a circulator called? |
The Volute |
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What are the 3 types of piping systems in heating? |
Series or perimeter loop Mono flow or one pipe system Two pipe direct system |
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What is the BTU limit on a series or perimeter loop? |
50000-60000 BTU/Hr |
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How does a condensing boiler work? |
Reverts steam back to water producing 970 BTU/lbs of condensate. |
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What fitting must be installed on a mono flow or one pipe system? |
A Venturi Tee |
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How does a Venturi tee work? |
Fluid speeding through Venturi nozzle draws fluid in from side branch, this moves heat fluid through the heater |
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What is the highest temperature you can set a high limit controller to? |
250F |
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What does the code require on any boiler when it comes to controls? |
Must have 2 temperature controls on any boiler, hence the operating control and high limit |
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How far can the discharge or a safety relief valve be from the floor? |
No lower than 6 inches and no higher than 12 inches |
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What is considered best practice on the end of a discharge pipe? |
Cut the pipe at an angle to prevent any type of pipe or fitting connection. |
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What must an air vent have for service? |
An isolation valve |
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What are the three types of air separation devices? |
Boiler fitting Line scoop Microbubble resorber |
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How does a Venturi tee work? |
Fluid speeding through Venturi nozzle draws fluid in from side branch, this moves heat fluid through the heater |
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What must be installed on a two pipe direct return system? |
Balancing valves, due to being prone to short circuits. |
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What does the ASME code require for low mass boilers? |
Low mass boilers over 40MBH. Must include a flow switch to prevent the boiler from firing in the event of no flow through the heat exchanger |
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What problems can occur in a conventional boiler if the flue gases are cooled to their dew point? |
Draft hoof spillage or damage caused by corrosive condensate |
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Best location for a circulator in a hot water heating system? |
Downstream of the compression tank. |
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What are the circulating pumps used on a hydronic heating system called? |
A centrifugal pump |
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What are the two classifications for centrifugal pumps? |
Low head High head |
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What are the characteristics of a low head centrifugal pump? |
Generally have 1/2 HP motors or less Operate below 12 feet of head pressure Pumped head pressure is less than the static head or operating pressure of the system. |
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What are the characteristics of a high head pump? |
Over 1/2 Hp motors Operate over 12 feet of head pressure Pumped head pressure is greater than the static head or operating pressure of the system |
