Gas Flashcards
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who is responsible to ensure all tools + equipment used on gas are in good conditions and working properly
responsibility lies within the installer who should be trained in a competent person
name of regulations that deals with personal safety
health and safety welfare act
main constitute of gas + natural gas
LPG = propane natural gas = methane
2 Reasons Why appliance could emit carbon monoxide as poc
lack of oxygen poor ventilation, flame chilling equals debris on the burner flame touching the heat exchanger
flue size is determined by various factors list them
appliance rated heat input, length of flue horizontal runs, resistance (turns and bends), height of flue
what key safety device must be fitted to a fanned draught open flue to prevent burner ignition should the fan fail
a fan sensing device is fitted to ensure burner does not turn on if fan is not working
name for points to be recorded on a notice of Hazard for a hazardous installation
name of issuer, name of customer, address of premises, gas type, hazard type, appliance
state one service that gas pipe work must not be installed alongside in service shaft
gas pipe must not be installed in duct/ services shaft where ventilation or air conditioning air
what is the permitted working pressure loss for natural gas + LPG between meter outlet plus appliance inlet
LPG = appliances on full 2.5 bar Max, natural gas = appliances on full 1 bar Max
what is meant by heat input of a gas appliance
volume of gas used in one hour in kilowatts
name three types of gas fires
live inset, radiant, radiant convector, flueless
what is the minimum ventilation for tumble dryer
less than 3kw
list two functions of a flue on a gas appliance
deposit poc to outside atmosphere, help maintain proper combustion
name three points to determine whether an appliance needs a flue
appliance heat rated input, volume of room, length of continuous use if over 7kw
how much ventilation is required for room sealed appliance (boiler 12kw) in compartment vented directly to outside 450mm cubed/kw
12 x 450 = 5400mm squared
what regulations refers to ventilation requirements for domestic gas appliance
Tec reg doc f
where are the concentration of gases between the lower and upper limits in a room/confined/ enclosed area may cause an explosion
where are the concentration of gases between the lower and upper limits in a room/confined/ enclosed area may cause an explosion. lower 5% upper 15% flammability limits
what elements of Fire are removed restricted smothered by a fire extinguisher
oxygen + heat
what is the function of the primary air port on a pre aerated burner
provide air for combustion
explain why it is necessary to carry out combustion testing on gas appliances
because incomplete combustion will lead to poc being carbon monoxide
name for key points recorded on declaration of conformance
name of installer, name and address of customer, date plus time, work carried out, ventilation conformance
describe the requirements for sitting of an emergency control valve in a flat or compartment where meter is remotely located notice must indicate what action must be taken
emergency control valve should be located near as possible to point supply enter flat, should be accessible and marked
calculate the size of pipe required to deliver 22kw, 15m calorific value is 11.6
22 / 11.6 = 1.9 needed over 15m answer to 22mm pipe
why would you fit an anti tilt device (stability bracket) to a gas cooker
this is fitted to a gas cooker that has drop down doors
min ventilation required if more than one flueless appliances fitted in the room
must be at least 13000 mm squared of ventilation when more than one flueless appliance
list two safety devices on a sealed central heating system
safety valve expansion vessel boiler stat hi limit stat gauge
list two functions of a flue
deliver poc to outside atmosphere
safety
help maintain proper combustion
name 4 parts of an open flue on a gas appliance
primary flue
draught diverter
secondary flu
terminal
how much ventilation required for 30 kW open flue boiler air allow 450
30 x 450 = 13500 mm squared
name three methods to reduce heat loss on with flues
used double lined flue
keep flue inside
insulate
keep the flu short as possible
list two main checks carried out prior to installation
CE mark right gas ventilation soundness test gas pressure appliance rated pressure
primary way of identifying gas content in a gas cylinder
collor on bottle
colour of bottle
label on bottle
what regulation must be referred to when installing a gas appliance over 60 kW
industrial/ commercial
IS820 deals with gas insulation over 60 kW
state volume of air required for complete combustion of 1 cubic metre of natural gas
10 m cubed or 10 - 1
what is the purpose of flame retention whole used on some gas cookers
prevent frame lift
keep pilot burning
what is meant by pre aerated flame
this means that some or all of air for combustion is provided before the gas leaves the burner
if gas installer discoveries a gas leak that cannot be repaired immediately what must they do
with customers permission isolate gas supply at the metre until it made safe if you’re not permitted by customer to isolate gas supply declaration of non conformance issued. ring board gais inform them of unsafe installation
name four key points that must be recorded on a declaration of conformance
installers name
customer’s name and address
time + date of work carried out
ventilation
name three types of pressure reading that can be taken on a gas installation
standing pressure
working pressure
appliance burner pressure
what is the procedure for checking gas rate when there is no metre present
check injector size to manufacturer size check inlet pressure plus pressure at burner
what is the minimum required diameter flue pipe suitable for DFE gas fire
minimum size for the who is 175 mm/7 in across axis of flu
minimum ventilation required for a cooker fitted in a bed sitting room
13000 mm squared
list two safety devices found on a sealed heating system
safety valve expansion vessel boiler stat hi limit stat gauge
with who does responsibility lie with to ensure tools equipment using gas installation are in good condition and are complete with safety guards where appropriate
responsibility lies with the installer who should be properly trained and competent
building regulations tech document l deals with
part L deals with conservation of fuel and energy
name the main constituent of natural gas
methane
what is the purpose of an injector
gas enters the burner tru injector orifice to provide exact measurement of gas
list two reasons why an appliance could emit carbon dioxide as a product of combustion
- interference with flame (flame chilling)
debris on the burner flame touching the heat exchanger - Lack of oxygen insignificant ventilation lack of primary air
explain why it is necessary to do combustion test on a gas appliance
it is done because incomplete combustion will result in carbon monoxide being produced
blue size is determined by many factors list them
appliance heat input
height of flue
resistance of flow
total length of horizontal runs
in relation to flue gases + air for combustion what a difference between room sealed + open flue appliances
room sealed = this appliance take all of it air for combustion from outside atmosphere
open flue = this appliance takes air for combustion from the room the appliance is in
what ventilation is required at low-level per kilowatt for open flued boiler in air compartment which is vented into the room
1800 mm squared
what is minimum height of an open flued terminal exiting through a roof with a pitch not more than 45°
600 mm less than 45°, 1000mm greater than 45°.
what must be maintained when gas metre/pipe/fitting is removed or replaced
electrical continuity must be maintained
what is the difference between hazardous + substandard Insulations
hazardous= e.g gas heat
something that could kill injure a person or property
substandard = not client with IS813 standards + regulation/ not installed properly EG clips wrong fuse not sleeved no brackets
name four key points recorded on a declaration of conformance
installers name/company customer's name + address appliance installed soundness test performed ventilation details time + date of work signature of installer + customer
what is Max recommended distance between brackets on copper pipe 15mm horizontal and vertical
1.2 m and 1.8 m
how would you find working pressure going to a boiler
a gauge should be connected to the inlet test point when appliance is on full
what extra safety requirements considered when installing cookers with drop down oven doors
these cookers must be installed with a stable bility device such as the stability bracket, safety chain
what is the purpose of a fuse for heating system what size should it be
protection for gas boiler fuse size 3 amps
name two rooms where open flue central heating boilers can’t go
bathroom shower room domestic garage
minimum ventilation required for cooker fitted in a bed sitting
13000 mm squared
minimum height of a flue exiting through a roof pitch greater than 45° and less than 45°
1000mm for greater than 45° and 600mm for Less Than and 45°
commissioning a gas cooker list main checks
all safety devices work burners are good condition CE mark on appliance ignition system ventilation FS devices are working
what needs to be done with gas installation installed before current standards
bring it up to current standards
who gets a declaration of conformance
everyone who installation conforms with standards + regulations set by is813
who gets a declaration of conformance
everyone who installation conforms with standards + regulations set by is 813
minimum height of a ladder has to rise above the place of landing
minimum of 1.1 m
regulation tech document l deals with
conservation of fuel + energy
main continuity bulk LPG
propane
main continuity of bulk LPG
propane
purpose of flame retention holes on some gas burners
prevent flame lift/ keep main pilot light burning
function of primary airport on a pre aerated burner
provide air for combustion
treating dad digital combustion Analyser can detect
carbon dioxide
carbon monoxide
nitrous oxide
oxygen
four major components of natural draught open flue system
primary flue drafted diverter secondary flue terminal
when gas supply is located in same duct as electrical cables what must be done
space inside Plus out insulate 35mm space for maintenance
why would you purge LPG different than natural gas
you would Purge LPG to outside atmosphere due to its density in comparison to air air = 1 LPG = 1.5
what method is used to ensure gas appliance is actually achieving it’s rated heat input
performance test
2 signs of open flue gas appliance is dangerous
soot, condensation, in correct flame
minimum vent for tumble dryer
6500 m squared
primary way of determining type of gas contained in cylinder
colour of the bottle
collor on the bottle
labels on the bottle
duty of employer set down in the safety health + welfare Work Act
employer duty is to provide a written statement of its general policy with respect to health + safety at work of its employees
explain what is meant by relative density of gas
this is the weight of a given volume of gas to that of same volume of air weight of gas compared to that of air
what is the purpose of flame retention holes
prevent flame lift
keep pilot flame burning
list two reasons why appliance code emit carbon monoxide as poc
lack of oxygen
flame chilling debris on boiler flame touching heat exchanger
some combustion Analyser display carbon monoxide in PPM what does this mean
PPM= parts per million
what’s the difference between open flue plus room sealed appliance
room sealed = takes air from outside for combustion
open flue appliance = takes air from inside room for combustion
how much ventilation is required at low level for open flued appliance in compartment vented to the outside allow 900 mm squared kilowatt boiler 24kw
900 x 24 = 21600 mm squared
name three places and open flue appliance is not permitted
bathroom showroom domestic garage bedroom
list two main check to be carried out on appliance prior to installing it
does it have CE mark right gas for appliance safety devices working soundness test right ventilation
incorrect warning signs + lack of signage on gas installations is a sign of what
sign of substandard installation
what must be issued to customer after a hazard repaired successfully
declaration of conformance
state two requirements of gas supply pipework installed behind dry lining wall
must be soundness tested
no compression fittings used
use cupro no fitting if possible
how would you find the working pressure going to a boiler
U gauge should be fitted to the inlet test point on the boiler should be tested when boiler on full allowed (1 mbar drop)
name two categories of space heater
open flue
room sealed
clueless
name two categories of space heater
open flue
room sealed
flueless
min ventilation required for tumble dryer
6500 mm squared + openable window
what should be fitted to a sealed central heating system should Primary boiler start fail
hi limit stat
two gas fires that have a heat exchanger
radiant convector
gas fire
inset live
what is the purpose of a heat exchanger
increase overall efficiency of appliance allow connected heat to be admitted from heat exchanger as well is radiant heat
what is least efficient gas fire
DFE decorative fuel effect
name two types of space heating appliances that do not require a chimney
fan assisted open flue gas fire
condensing gas fire
what is the most efficient gas fire
radiant convector gas fire
document l deals with
conservation of fuel + energy
main constituent of LPG + natural gas
LPG = propane
natural gas = methane
purpose of flame retention holes
to prevent flame lift
to keep main flame burning
what is function of the primary airport on a pre aerated gas burner
primary air port on a gas burner is to provide some or all of the air for combustion before the gas leaves the burner
name three items a digital combustion Analyser can identify + determine in flue gases
- Carbon dioxide 2. Carbon monoxide 3. Nitrous oxide
list four components of a natural draught open flue system
primary flue
draught diverter
secondary flue terminal
minimum ventilation for copper in a bed sitting room
13000 mm squared
when commissioning a gas cooker for main points to be checked
check ignition system
inform customer how to operate
ensure working pressure at burner is correct
clear work area
who is entitled to a declaration of conformance
everyone customer who is installation + ventilation is conformance with is 813
where a gas supply is located in same duct as electricity cables what must be done
must be spaced out or insulated 35mm ducts must be ventilated
in what way would LPG be purged differently from natural gas
you would Purge LPG out in the outside atmosphere as is heavier than air
air = 1 LPG = 1.5
what method is used to ensure gas appliance is actually achieving its specified rated heat input
performance test
list two signs that open flue gas fire is dangerous
soot, condensation, unstable combustion
what is minimum ventilation required for tumble dryers
6500 mm squared openable windows
what type of safety valve is recommended on a domestic heating system
no2 safety valve gauge Incorporated sealed system 3 bar
are compressed fittings allowed in concealed areas
no any compressed fittings should be accessible
how to thick must the brick work be on a chimney
25mm minimum
what does the H+ s welfare act provide for employees
employer must provide a written statement of its policy with respect to the H+ s welfare act provide a safe working environment
what is the max shutdown time for flame supervision device fitted to decorative gas fire
120 seconds/2mins
what are most common cause of carbon monoxide
lack of oxygen insignificant ventilation
flame chilling flame touching heat exchanger
what is produced from incomplete combustion
carbon monoxide
what are main signs of carbon monoxide
stain of appliance, soot, unstable combustion
what is calorific value
the amount of heat released by the complete combustion of a measured volume of gas
name 6 parts of a multifunctional gas valve
pilot flame adjustment valve solenoid valve gas pressure adjustment point operating button inlet pressure test point burner pressure test point
what is flame supervision device used for
to prevent unlit gas passing into the combustion chamber through the burner
when will supervision device work
pilot light fails to light when ignition applied main burner fails to light when ignition applied pilot lights or main burner go out after ignition
how does supervision device work
by using the heat from the flame the flame acting as a conductor to complete an electrical circuit
what are main disadvantage of flame conductance device
a short circuit can simulate presence of a flame EG if electrodes touch each other it will fail to shut off gas
list three components of a multifunctional valve
solenoid valve
inlet pressure test point
pilot adjustment valve
what points to consider when planning and installation
pipe sizing future installation how many appliances ventilation Nat gas + LPG gas pipe material resistance to fire
what is melting point of Nat gas + LPG gas
Nat gas = 210°c
LPG gas = 450°c
name four places where you can’t put carcass pipework
under foundations
under base footing of load bearing wall
in cavity of a cavity wall
service duct ventilated Lloyds
name three points to consider when sizing pipe requirements
Max rated heat input of all appliances + add-ons length of pipework run
route of pipework
what is minimum depth of pipework buried outside
minimum depth is 375 mm with 150mm of sand either side
what must be done to pipework in concrete or driveways
must be sleeved also coated minimum of 25mm of crack free concrete
what protection practice is used for mild steel pipes outside
two coats of bituminous paint
when working with naked flame on existing installation what care must be taken to avoid
flashback to gas storage vessel
damage to decoration + combustible materials
gas pipe going through joist should be what size
no greater than 1/8 of the depth of the joist holes no greater than 1/4 of depth of joist
name two things when gas pipe runs in ducts
- must be ventilated top + bottom
2. integrity of fire resistance to be maintained
what is temporary bonding
temp bonding is done so electrical continuity is maintained. At all times cable with insulated clamps at each end (jumper leads)
when commissioning a gas appliance name for important to consider
- General condition of insulation + appliance
- adequate ventilation available
- Ability to remove pocs to outside atmosphere 4. Adequate air for the combustion process
minimum checks to be made for new installation of a gas appliance
soundness test pipework purged metre outlet working pressure appliance working pressure flue ventilation
name 5 types of gas fire
radiant convector radiant live in set decorative fuel effect DFE flueless
name three Florida open flue appliance used where no chimney exists
- fan assisted open flue gas fire
- Fan assisted closed flue convector
- condensing gas fire
what is a closure plate what is it used for
a. it is a steel plate 3 - 6 mm put in front of fire with a spigot for the flue
b. It is used to change the amount of air changes in the room from 7 - 2
what is flue size for radiant convector fires
125mm 5 in to cross axis of flue
what is flue size for inset live
125mm 5 in Cross axis of flue
what flue sizes for decorative fuel effect
175mm 7-in across axis of flu if spigot is less than a 13000 mm squared
what is standard size of brick chimney
9 x 9 in
closure plate size should be what
this should be 50 mm wider 25mm higher
what distance should gas fire be off back of Builders opening
at least 50 mm. From the back wall
what thickness minimum should the heart be
50mm
name two types of room sealed appliance
radiant convector fires
convector wall heaters
what is commonly known as a letterbox
hello opening in the closure plate 350mm wide 400mm high
text before installing an open flue gas fire wall hung heater
type of room. type of appliance. ventilation. gas connection. Combustible surfaces. risk of injury
safety check list pre installation gas fire
does s carry the CE mark is applying suitable for that gas safety devices are installed control tap work properly radiants is there a closure plate is the flue correct suitable
what is purpose of a flue
remove poc to the outside atmosphere
to maintain proper combustion
what can affect performance of flue
it's cross sectional area termination point number of bends heat loss climatic conditions it's condition
when does an appliance need a flue
when over 7kw
how you determine whether or not appliance requires a flue
rated input of appliance
period of continuous use
room volume
what amount of kilowatts determines whether is a domestic or commercial
domestic = 60 kW under
commercial = 60 kW over
name five rooms open flued appliances can’t go
bathroom
shower room
domestic garage
bed sitting room
flue termination point flat roof
greater than 1500mm from wall
less than 1500mm from wall
greater than 1500mm /24 in from wall
less than 1500mm/ 24 in from wall
flue bends horizontal Max of Bend and vertical
horizontal 45° Max
vertical 135° Max
what is the minimum vertical run from Fire before any bands
least 600 mm
how can you prevent heat loss of flue and condensate or gases
keep flue short as possible used twin wall flue keep surfaces to calculated minimum insulate if necessary run flue internally
how can you protect the flu as it passes through roof floor ceiling or partition
sleeve the flu 25mm
in hot press are covered protected by mesh wire with 50mm air gap so nothing come in contact with flue
flue pre-installation check
discuss with customer checking manufacturer specs check location is suitable for flue check if other open flue appliance is in room check adequate ventilation check flue can be terminated correctly
advantages of balanced flue appliance
safer appliance don't need to take air from room easier to install can insulate in any room minimises condensation in flue neater when installed
what is minimum ventilation under building regs
6500 mm squared
if chimney in room 12000 mm squared
what is adventitious ventilation
adventitious ventilation is air that can enter room through cracks around doors + openable windows
4 points to consider when calculating ventilation for flueless appliance
- must communicate with outside atmosphere directly
- there is sufficient room volume for the proposed type of appliance
- note any restrictions on appliance
- All flueless appliance require openable window
- Small room require purpose provided ventilation
- Size of appliance in kilowatts
- Any other appliances flued or flueless in the room
what is a closure plate
to reduce air changes in a room and control the pull of the flue
3 types of cookers
free standing built in built under
