Note's Flashcards
Any person involved in the installation, removal, repair, inspection, and servicing of a pressure relief device shall?
be trained and competent
Which one of the following devices is typically used for steam or vapour service?
a) relief valve
b) safety valve
c) safety relief valve
d) temp and press relief valve
b)
Which of the following is typically used for a liquid service?
a) relief valve
b) safety valve
c) safety relief
d) temp and press relief
a)
What is the usual temperature and pressure relief valve setting?
a) 150f
b) 180f
c) 210f
d) 212f
c)
Safety, safety relief, and relief valves shall be of the
a) direct spring loaded type
b) indirect spring loaded type
c) internally weighted type
d) rupture disc type
a)
What type of valve may be installed between a boiler and its relief valve?
no valve at all
When a vacuum relief is used for low pressure steam devices a _______ must be installed to prevent live steam from damaging the device?
pigtail
What is the LNG secondary relief valve relief pressure set at?
a) same pressure as the MAWP of the tank
b) 1.5 times the MAWP
c) 2 times the MAWP
d) 2.5 times the MAWP
b)
What pressures are propane tank safety valves set at?
a) 250 or 312psi
b) 250 or 375psi
c) 295 or 375psi
a)
What pressure is a propane cylinder safety valve set at?
a) 250psi
b) 312psi
c) 295psi
d) 375psi
d)
Propane produces ___ft3 of air per 1ft3 fuel
25
Natural gas produces ___ft3 of air per 1ft3 fuel
10
Calorific value of natural gas?
1000btuh
Calorific value or propane?
2520btuh
Expansion ratio of propane
1:270
Expansion ratio of natural gas
1:600
Combustion air supplies
- comb. air: __ft3/1000btuh
- exc. air: __ft3/1000btuh
- dil.air: __ ft3/1000btuh
- total air: ___ ft3/1000btuh
- 10
- 5
- 15
- 30
ASME stands for?
American society of mechanical engineers
Primary LNG relief is set at the MAWP of the tank. True or False?
True
Secondary relief valve is exposed and primary is piped away. True or False?
True
Anything over 2 1/2” must be welded. True or False?
True
Depth of dirt or drip pocket is?
3” minimum
Nipple diameter is the diameter of the piping being served or __NPS. Whichever is less
2”
What are the liquefied petroleum gases (LPG)?
a) butane and air
b) propane and air
c) propane and butane
d) methane and butane
c)
What is the air to fuel ratio required to achieve stoichiometric combustion?
a) 1:1
b) 2:1
c) 5:1
d) 10:1
d)
What is the yield formula for the stoichiometric combustion of methane?
= 1,2,8
Why is digester gas considered a renewable resource?
a) it does not cost any money to make
b) generates no net co2
b)
Propane-Air systems do not require additional gas trains, piping, or special fuel delivery systems within the building it serves. True or False?
True
All combustion chambers are suitable for alternate fuel combustion. True or False?
False
What are all the conditions that must be met to ensure correct application and selection of a conversion burner?
a) fan speed and colour
b) combustion air geometry, fan speed
c) firing rate, combustion chamber geometry, and flue gas travel
c)
Why is biomass fuel considered to be a renewable energy source?
a) it does not cost any money to make
b) generates an abundance of co2
c) photosynthesis cycles the co2 back into new crops
c)
If a liner cannot be installed in a masonry chimney, what must be done to accommodate a conversion from oil to natural gas?
a) new venting system must be installed
b) special draft inducer
c) special concrete wash
a)
When piping a gas supply system of 5psi and up. What calculation must be considered?
Friction loss of fittings
Minimum gas pressure for propane?
1.5’’
Minimum gas pressure for natural gas?
3.5’’
Why are vacuum reliefs on tanks required?
To prevent an extreme vacuum from a fire truck hook-up
Draft hood appliance requires a total of ___ft3
30ft3
Draft hood requires __ft3 for combustion and __ft3 for the draft hood
15ft3 and 15f3 for a total of 30ft3
Purpose of a draft hood is to provide air to mix with ____ gases and reduce the speed of them and reduce _________
flue gases, condensation
Speed of flue gas is _______ to speed of fresh air pulled in
inverse
Considerations when selecting OPPD? (3)
- Continuity - how important is gas interruption
- Where - where will gas relief
- Failure - how is failure detected
Name four types of OVER PRESSURE PROTECTION
- monitoring
- pressure relief
- series regulation
- overpressure cut-off
When inlet pressure on the first regulator exceeds downstream pressures, you must have _________ ________ installed
over pressure protection
_______ valve is considered the most reliable type of OPPD
Relief valve
Why are relief valves considered the most reliable type of OPPD? (3)
- do not block flow
- do not decrease capacities of regs
- alarm if they vent to atmosphere
Name 4 types of relief valves
- pop type
- direct operated
- pilot operated
- internal relief
Vent limiters must be installed ______
upright
Vent limiters replace regulator _______ in certain situations
regulator venting
Vent limiters allow a slow escape of gas if the ________ rips
diaphragm
Vent limiters can only be installed ?
indoors
Surge arrestors are also known as ?
vent stabilizer or flapper assembly
Surge arrestors protect the regulator from?
Increased outside pressures pushing down on the diaphragm
Surge arrestors allow air to move _______ and allows gas to escape if necessary
freely
