checking safety devices on gas hob and oven

[g60rge]

hi, im working towards my acs and have a query,

if im checking safety devices on a gas hob/cooker,

letby/tightness

lid shut off

check controls are working and not letting by or stiff/loose

check stability device/hose connections etc

i check the fsd by lighting the oven and watching it light on low flame, once the phial has heated up it allows the main burner to light (30 secs). Shut the gas off, wait for the click (time it) turn back on, should start off on low flame again.

check the flame returns to bypass after temp is satisfied

check the seals with a sheet of paper

now ive found nothing in my notes to suggest checking ffd shut off on hobs and cookers and doing the tightness test to ensure gas isnt being passed to the burners which worries me.

thinking about it, if the gas supply was interrupted and then reinstated, but the ffd shut the gas off, how is the appliance reset? as ive never seen one with a reset button. if they dont, then what happens?

thanks in advance

 

[SimonJohns]

Certain hobs nowadays have an fsd

Other than that there is only clearances etc.

 

[mikegas]

"i check the fsd by lighting the oven and watching it light on low flame, once the phial has heated up it allows the main burner to light (30 secs). Shut the gas off, wait for the click (time it) turn back on, should start off on low flame again."

there will be no click on an oven vapor pressure fsd, after your 30 sec you just turn gas off and wait 90 sec max then relight, it should then light on low flame

 

[g60rge]

i did realise that but the college will probably have old appliances in there.

any advice what i should do in my acs exams if the mi's dont say if it has one or not?

 

[mikegas]

to check cooker lids light the cooker burners and lower the lid, gas should turn off

 

[g60rge]

"i check the fsd by lighting the oven and watching it light on low flame, once the phial has heated up it allows the main burner to light (30 secs). Shut the gas off, wait for the click (time it) turn back on, should start off on low flame again."

there will be no click on an oven vapor pressure fsd, after your 30 sec you just turn gas off and wait 90 sec max then relight, it should then light on low flame

ahh i see, thats all i need to check then, other than the other stuff i mentioned, thats good.

how about the hob? all i remeber doing at college and with the engineer i was with on my portfolio (whom i dont like bugging too often which is why im here) is check the controls are working correctly and the flame looks good.

 

[mikegas]

ahh i see, thats all i need to check then, other than the other stuff i mentioned, thats good.

how about the hob? all i remeber doing at college and with the engineer i was with on my portfolio (whom i dont like bugging too often which is why im here) is check the controls are working correctly and the flame looks good.

if it doesnt have a lid or fsd's on the hob the yes

 

[g60rge]

to check cooker lids light the cooker burners and lower the lid, gas should turn off

i knew that one lol thanks

 

[g60rge]

if it doesnt have a lid or fsd's on the hob the yes

thats great, this website really is proving helpfull..

last q
if the mi's dont mention the fsd, or on the tools there are no mi's, what would be the sign that the hob has an fsd?

 

[mikegas]

i knew that one lol thanks

ok, good luck

 

[g60rge]

should hear the click?

 

[dancinplumba]

thats great, this website really is proving helpfull..

last q
if the mi's dont mention the fsd, or on the tools there are no mi's, what would be the sign that the hob has an fsd?

each burner will have it pointing into flame, you will see them

 

[g60rge]

each burner will have it pointing into flame, you will see them

i think i remember seeing those badboys somewhere, wasnt taught this in college, isnt in my books or my folder, by mentor never taught me either...

 

[g60rge]

each burner will have it pointing into flame, you will see them

got me thinking now, after the click/lockout - how is it reset?

 

[dancinplumba]

dont have to reset anything just relight burner by pressing on control knob

 

[Syty]

there will be thermo-couple, do not confuse it with ignitor.
You can light one of the burners and blow it. FSD should shut the gas within 60 sec max.
You can put your hand on the cooker and feel when FSD does work

 

[SimonJohns]

there will be thermo-couple, do not confuse it with ignitor.
You can light one of the burners and blow it. FSD should shut the gas within 60 sec max

Allowing gas to escape In to amtosphere. That's not very good lol

I know what you mean thou. Should just wait for allowed time and turn back on. No gas. Pass!

 

[g60rge]

hang on,

flame is lit on hob
i cut off the gas
after 60 secs it click shut
i turn gas back on and do a tightness test to check it has shut off and not passing gas to the burner - it passes
gas control is still on
how does it then go back to normal ie gas is allowed back in - is it when the control has returned to the off position?

 

[dancinplumba]

they are relatively recent and are now a requirement in houses of multiple occupation

 

[dancinplumba]

hang on,

flame is lit on hob
i cut off the gas
after 60 secs it click shut
i turn gas back on and do a tightness test to check it has shut off and not passing gas to the burner - it passes
gas control is still on
how does it then go back to normal ie gas is allowed back in - is it when the control has returned to the off position?[/QUOTE]
no just press down on control knob and relight burner,doesnt matter what position , flame touches t/couple again and stays lit

 

[Hobo128]

Just to change the subject because this thread is so fresh and im doing my acs too,
When purging existing pipework say after a service or something do you have to work out a purge volume to purge it or can you just purge 0.01 m3 of gas through. I understand that you have to work out purge volumes to check its within your limits.

 

[g60rge]

there will be thermo-couple, do not confuse it with ignitor.
You can light one of the burners and blow it. FSD should shut the gas within 60 sec max.
You can put your hand on the cooker and feel when FSD does work

ah i see the fsd in a hob is a thermoelectric valve

 

[g60rge]

hang on,

flame is lit on hob
i cut off the gas
after 60 secs it click shut
i turn gas back on and do a tightness test to check it has shut off and not passing gas to the burner - it passes
gas control is still on
how does it then go back to normal ie gas is allowed back in - is it when the control has returned to the off position?[/QUOTE]
no just press down on control knob and relight burner,doesnt matter what position , flame touches t/couple again and stays lit

just like on the fire place.

im so happy right now thanks every1

 

[dancinplumba]

just like on the fire place.

im so happy right now thanks every1

yes, well done just like a fire

 

[g60rge]

Just to change the subject because this thread is so fresh and im doing my acs too,
When purging existing pipework say after a service or something do you have to work out a purge volume to purge it or can you just purge 0.01 m3 of gas through. I understand that you have to work out purge volumes to check its within your limits.

if the gas pipe has been opened, i would do a purge calculation and follow the correct procedure to remove explosive mixtures!

 

[Syty]

it should click up to 60 sec. not after. Usually it does before

 

[Hobo128]

if the gas pipe has been opened, i would do a purge calculation and follow the correct procedure to remove explosive mixtures!

But what if you cant see the pipe work and you dont know how many fittings or how much 22mm pipe runs though the ceiling? Are you only doing purge volume caculations to check if you are allowed to purge it with out igniting. I am confused. Alot of the time you can see the pipework and you cant go ripping floor boards up.

 

[Syty]

Just to change the subject because this thread is so fresh and im doing my acs too,
When purging existing pipework say after a service or something do you have to work out a purge volume to purge it or can you just purge 0.01 m3 of gas through. I understand that you have to work out purge volumes to check its within your limits.

You have to purge installation if you had pipework open. If you did work on the boiler with isolation valve closed than no need to purge.

 

[Hobo128]

You have to purge installation if you had pipework open. If you did work on the boiler with isolation valve closed than no need to purge.

Yeah sorry mate i know this but what if for instance i have cut the pipe work and have to purge but cant see the pipe work to get the IV.

 

[Syty]

well if installation is up to 28mm it would be 0.01m3

 

[Hobo128]

So why do you need to work out a purge volume ?

 

[Hobo128]

well if installation is up to 28mm it would be 0.01m3

So why do you need to work out a purge volume ?
I mean cant you just purge 0.01m3 through everytime if the pipe work is not greater that 28mm. Dont forget im doing my acs soon and need explanation.

 

[GrahamM]

So why do you need to work out a purge volume ?
I mean cant you just purge 0.01m3 through everytime if the pipe work is not greater that 28mm. Dont forget im doing my acs soon and need explanation.

Correct. The standard purge volume for a G4/U6 meter with 28mm pipe is 0.01m³ as Syty states.
Only if bigger meter or greater than 28mm pipe does this change.

 

[kirkgas]

Just to change the subject because this thread is so fresh and im doing my acs too,
When purging existing pipework say after a service or something do you have to work out a purge volume to purge it or can you just purge 0.01 m3 of gas through. I understand that you have to work out purge volumes to check its within your limits.

check your notes and get your head round this you seem to be mixing a couple of things up
depending on meter and/or pipe size you only need to purge 0.01m3, if above 28mm or U16 meter there is a calculation to do, but a purge calculation isnt done to see if it is within limints of your work scope, the calculation is to work out how much gas to purge and whether you purge to air with no ignition or constant ignition
the calculation to decide whether you cvan work on it is IV (Installation Volume) and if over 0.035m3 isnt domestic

 

[kirkgas]

if the gas pipe has been opened, i would do a purge calculation and follow the correct procedure to remove explosive mixtures!

i wouldnt do a purge calculation until i had done a visual inspection to see what meter and pipes were fitted, as you dont need to calculate every install