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55 Cards in this Set
- Front
- Back
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Scale build up effect efficiency |
Insulate not transfer heat. |
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Mawp |
Max allow working pressure |
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Water tube |
Fire outside tube |
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Purpose if bottom blowdown |
Remove sludge. Remove water |
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Most important valve |
Saftey |
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What control operate steam |
Pressyrtrol |
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Hydrobic control |
Aquastat |
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What causes soot |
Improper combustion |
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What can cause incomplete combustion |
Lack of air |
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How to test diaphragm type expanse tank thats water logged |
Knock on side to see if hollow |
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Indication of water logged expansion tank |
Relief valve will open. No where for expansion to take place |
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Blower between furnace and stack |
Induced |
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Proper combustion stack smoke should look like |
Light haze |
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Mean if black smoke |
Incomplete combustion. |
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Heavy white smoke |
Tube leak |
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Purpose of water column |
To slow down water fluctuation so easier to read gauge glass |
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Correct time to blow down boiler |
When light load still warming up |
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Saftey valve leak |
Replace |
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Some cases blow down line has 2 valves what's the procedure to open |
Closes to boiler work way out then w9rk way back |
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When do you need two valves on bottom |
Exceed 100psi mawp |
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Benefits of proper water treatment |
Reduce corrosion. Reduce scale buildup by removing oxygen giving proper ph |
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Good ph for hot water |
8 to 9 |
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Ph for steam boiler |
10.5 to 11 |
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Dissolved gasses in water, most harmful is |
Oxygen |
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Which valve has unrestricted flow through it |
Gate valve |
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Gauge glass is full, what mean |
Top valve closed or boiler is full. Open top cock to see what comes out |
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Water level not moving |
Bottom valve is plugged |
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How often test saftey valve |
Monthly |
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Proper way to warm up a gauge glass |
Crack open the top valve. Slowly let steam in |
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Purpose of expansion tank |
As heat goes up pressure goes up. Volume of water changes so tank handle the changes of water volume |
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What 2 devices control the flow zoned system |
Zone circulator or zone valve |
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What happens if circulate oversized |
Frequent burner cycling efficiency goes down. Delta t goes down. |
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Undersized circulator |
Insufficient heat. Not proper gpm |
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What does a siphon do and how |
Protects steam from entering gauge glass or pressurol. Traps steam with water in bottom |
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Wtf does a lwco do? |
Shut off burner when water level gets too low |
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Remedy for cold hydronic boiler |
Bleed out air |
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Evaporation test how to? |
Shut off feedwater and let the boiler run |
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How often does steam boiler need internal inspection |
Annualy |
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How often does hydronic need internal inspection |
5 year |
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Which boiler can't be used on high pressure |
Cast iron |
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What can cause boiler explosion |
Out of water adding water to hot dry boiler. Unburned fuel |
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Purpose of pre purge |
Clears out combustion chamber |
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Common chemical used as oxygen scavenger |
Sodium sulfite |
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Common set point for relief valve low pressure hot water |
30psi |
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What does thermostat directly control on multi zone system |
Zone valve or zone circulator |
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What enable the aquastat relay on multi zone system |
Zone valve, end switch, thermostat |
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Commercial boilers have how many aquastat |
Usually 2 |
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Commercial boilers have what kind of aquastat |
High limit and operation |
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Purpose of surface blow down |
Impurities that are on the surface |
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What is water hammer |
When water droplets bang into steam piping around turns. Steam boiler |
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What causes water hammer |
Surface tension |
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Calculate gallons per minute |
Btu/hr ÷ (Delta t×500) |
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Calculate head pressure |
ML × 1.5×.04= |
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Calculate btu |
Btu out ÷ 33472 |
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Minimum like size for steam pipe |
1/4 inch |
