Ch. 5 Quiz Flashcards
propane tank must be __ft. away from a source of ignition
10ft.
propane tank must be __ft. away from an air intake
10ft.
propane tank must be __ft. from an opening of a building
5ft.
1st stage regulator is responsible for… (LP)
variance in tank pressure
inlet pressure of 1st stage regulator (LP)
20 - 80 psi
outlet pressure of 1st stage regulator (LP)
10 psi
2nd stage regulator is responsible for… (LP)
variance in down stream pressure
inlet pressure of 2nd stage regulator (LP)
10 psi
outlet pressure of 2nd stage regulator (LP)
11 - 14” w.c
max lockup pressure
120% of the 2nd stage regulator’s outlet pressure
bounce of 2nd stage regulator can be up to..
1” of w.c (.5 up or .5 down)
the allowable pressure drop for 2nd stage regulator
.5” w.c
pressure available @ appliance
No more than .5” w.c less than 2nd stage outlet’s pressure
What code covers first and second stage regulators (LP)
NFPA 58
NFPA 58 states what about single stage regulation
single stage regulation shall not be installed in fixed piping systems
what is required when the supply pressure is higher than what the appliance is designed for
Vent Limiter ( line gas pressure regulator)
inlet of 1st stage regulator pressure
usually 20 - 80 but less than 312 psi
rubber diaphragm in a regulator senses..
gas pressure
the lever actuator and seat disk do what…
meter the amount of gas
what does the spring in a regulator do..
controls the flow of gas
foreign material between inlet nozzle and seat disk causes …
no lockup and creeping (lg rise over 5 min)
a relief valve is required on..
final stage gas regulators
what does the vent of the final stage regulator do
vents excessive gas pressure
obstruction of regulator vent causes what?
prevention of excessive pressure relief and prevention of diaphragm
regulator vents shall prevent what
water from entering (face down) insects (screen) foreign materials (paint)
regulator vent shall terminate __ft from source of ignition (LP)
5’
regulator vent shall terminate __ft from source of ignition (NAT)
4’
when terminating a reg vent from indoors to outdoors vent must terminal how?
90 degrees vent down with screen installed
gas meters must be readily accessible for…
examination
reading
replacement
maintenance
gas meters must be identified by..
metal tag or other perm. means of designating the building or part of building it supplies
3 factors that determine how much a customer should be billed
heat content - (sgs knows the blend)
inlet pressure - (meter adjusted at install)
temperature - (meter/sgs adjust meter for temp)
meter set (meter & reg combo) located __ ft from opening
at least 3’
what shall not be used in gas piping systems
cast iron
what kind of black iron shall be used
min. sched 40
when will plastic tubing be used..
outside underground only
pvc used on outdoors regulator vents shall be what
UV resistant (electricians PVC)
when metallic piping is used outdoors what must be done?
protected usually paint
what kinds of teflon tape can be used as a thread joint compound?
blue monster or other approved material (UL listed)
Four acceptable means of joining metallic pipe
Threaded
Flanged
Brazed (excess of 1,000)
Welded
largest size pipe that can be threaded without approval from ahj is..
4 inches
When pipe is over 4 inches the two methods of joining are
Flanged and welded
