Notes: Flashcards
CH4 Methane Temperatures
- _____ approx ignition temp
- ______ approx flame temp (air)
- ______ approx flame temp (oxygen)
- 1300F
- 3600F
- 5900F
C3H8 Propane temperatures:
- 920F approx ______ temp
- 3600F approx ______ temp (air)
- 5900F approx ______ temp (oxygen)
- ignition
- flame
- flame
Ch4 methane has a calorific value of ______btu/ft3
1000btu/ft3
Ch4 methane has a specific gravity of
0.55 or 0.6
Liquid methane has a specific gravity of
0.3
C3H8 propane has a calorific value of
2520btu/ft3
Why is propane dangerous?
it is denser than air so it will fill a room ground up before you smell it
C3H8 propane has a specific gravity of
1.52
Liquid propane has a specific gravity of
0.51
Methane Expansion Ratio:
- Boiling point:
- 1 ft3 liquid =
- -260F
2. 1:600ft3
Propane Expansion Ratio:
- Boiling point:
- 1 ft3 liquid =
- -44F
2. 270ft3
What is the Volume, Pressure, Temperature Formula
V1T2P1 = V2T1P2
What does ASME stand for?
American society of mechanical engineers
Combustion air supplies:
- combustion air = __ft3/1000btu
- excess air = __ft3/10000btu
- dilution air = __ft3/1000btu
- total air __ft3/1000btu
- 10ft
- 5ft
- 15ft
30ft
Propane tank relief valve setting is at ?
312 or 250psi
propane cylinder relief valve setting is at ____psi
375psi
Primary liquid natural gas relief valve set at ____ of tank
MAWP
secondary liquid natural gas relief valve set at ____ times MAWP of tank
1.5 times
Secondary relief valve is _______ and primary is piped away
exposed
Air supply inlet opening from outdoors shall be located not less than ___” above outside grade (code) but safety regulation requires __”
- 12”
2. 24” (right answer)
Anything over ___” nominal pipe size must be welded
2 1/2”
Depth of dirt or drip pocket is minimum _”
3”
Two types of oil fired burners:
- flame ______- head
- high ______ burner
- flame-retention head
2. high static burner
Why are duplex filters used?
allows for replacement of one without disrupting the other
what does a premix (inspiration burner) use to entrain air?
gas under pressure
What does a premix (aspirator) use to create a negative pressure and draw in gas?
air pressure
forced draft is produced by a device ________ of combustion chamber
upstream
Fan assist is located ______ of combustion chamber
upstream
Forced draft requires a strong fan as it overcomes resistance of the appliances heat _______
exchanger
A typical pilot burner has an ______ orifice
insert
The more tapered angle of approach on an orifice means a higher ____ flow rate
gas
Higher _ factor means better flow characteristics through the orifice
K
Use a hand ____ to adjust orifice sizes
hand
larger drill size the _______ the hole
smaller
choose ______ orifice if between numbers
smaller
Orifice flow fundamentals:
- doubling the area ______ the flow
- double diameter ________ the flow
- quadrupling the pressure ______ the flow
- quadrupling the specific gravity ______ the flow
- doubles
- quadruples
- doubles
- halves
Orifice size is determined by the _________
manufacturer
The higher the altitude the less _____ the air is and less oxygen it has
dense
Appliances shall be adjusted to the ____ _________ rating on the nameplate
high altitude
standard high altitude rating is _____-_______Ft
2000-4500ft
When an appliance is installed above 4500ft, the certified high altitude input rating shall be reduced at the ratio of __% per additional 1000ft
4%
