allowed drop when doing a tightness test...

[rickstar88]

Hi all,just thought id mention this because i had a heated debate with 2 other gas engineers about the drop allowance when doing a tightness test.Last week 1 of the engineers left a 2 millibar drop at a property and said it was fine to do so as it was a g4 meter..i said ok but could you isolate all the appliances,he said yes...then i said well if you isolate all of them and then do another tightness test and it still drops 2 millbar then your not allowed to leave it because your not allowed ANY drop on pipework OLD or NEW,he said your allowed up to 4 millibar on a g4 meter in all cases...so to back my point up i got him to ring gas safe and they told him he was wrong...just thought id mention it incase any other engineers have been doing the same thing...let me know your views and what you think....

[kirkgas]

Hi all,just thought id mention this because i had a heated debate with 2 other gas engineers about the drop allowance when doing a tightness test.Last week 1 of the engineers left a 2 millibar drop at a property and said it was fine to do so as it was a g4 meter..i said ok but could you isolate all the appliances,he said yes...then i said well if you isolate all of them and then do another tightness test and it still drops 2 millbar then your not allowed to leave it because your not allowed ANY drop on pipework OLD or NEW,he said your allowed up to 4 millibar on a g4 meter in all cases...so to back my point up i got him to ring gas safe and they told him he was wrong...just thought id mention it incase any other engineers have been doing the same thing...let me know your views and what you think....

this is 100% correct, the dodgy bit for me is that you dont NEED to isolate the appliances to confirm whether it is appliance or carcass leak, some people will argue that is wrong or poor working practice, but it has been confirmed many yrs ago with CORGI, if you have 2mb drop on existing carcass which has an appliance it is fine to leave. IF you choose to disconnect the appliance to assit identification of the leak and you find it is on the carcass it CANNOT be left

[GQuigley67]

i thought that with a 2mb drop or anything like that(within the limits) on an existing system it would be fine as long as there is no smell of gas? correct me if im wrong.

[rickstar88]

hi kirkgas,yeah it is correct...the bit i dont get is how people will think isolating the appliances is wrong or poor practice,as isolating them(if possible to do so) gives you the answer to your problem straight away...

[rickstar88]

Hi GQuigley67,the 2 other engineers who i am talking about thought exactly the same,as long as there's no smell of gas you can leave it on existing pipework if its within the limits,this only apply's if you have an appliance that cannot be isolated(e.g-a gas hob with no isolation tap).if you can isolate all the appliances then you are not allowed any drop on any pipework old or new...

[GQuigley67]

ok that's fine, i've never actually had a drop on the pipework before so have never had to do it, so was just wondering thanks

[rickstar88]

ok,cheers for your thoughts anyway...

[kirkgas]

hi kirkgas,yeah it is correct...the bit i dont get is how people will think isolating the appliances is wrong or poor practice,as isolating them(if possible to do so) gives you the answer to your problem straight away...

no what i meant was people will think it bad practice NOT to isolate the appliances

[Blackcatgas]

Hi GQuigley67,the 2 other engineers who i am talking about thought exactly the same,as long as there's no smell of gas you can leave it on existing pipework if its within the limits,this only apply's if you have an appliance that cannot be isolated(e.g-a gas hob with no isolation tap).if you can isolate all the appliances then you are not allowed any drop on any pipework old or new...

Hmmm..Ok so youve found a leak "within limits" on a gas carcass conected to a boiler, the boiler has an iso valve on it, where does it then say that you Have to then isolate the apliance and test again?. ( I will always Isolate first afetr finding a drop btw) Iam genuinly just interested.

[rickstar88]

ah right..i see what you mean kirkgas

[kirkgas]

Hmmm..Ok so youve found a leak "within limits" on a gas carcass conected to a boiler, the boiler has an iso valve on it, where does it then say that you Have to then isolate the apliance and test again?. ( I will always Isolate first afetr finding a drop btw) Iam genuinly just interested.

it doesnt say it anywhere, if it is carcass only you have no drop, if it is a new install you have no drop, if it is existing carcass with appliances connected there is a table to tell you the permisible drop, depending on meter and pipe size, some people interpret the regs as there being a need to isolate an appliance to check the carcass only, but you dont need to, i have no issue with anyone who does isolate an appliance to confirm it is on the carcass and therefore must be fixed, as long as they clarify it with the person who is ultimately going to get the invoice, as an aside, when i test an existing caracc with appliances and i find a drop i mark it on the paperwork to give the owner the opportunity to decide whether they want the leak fixed at a later date or not, as i interpret the regs as it being their choice after i have informed them, it is perfectly acceptable to tick the PASS box, but i always note the drop as well

[Reg Man]

Hmmm..Ok so youve found a leak "within limits" on a gas carcass conected to a boiler, the boiler has an iso valve on it, where does it then say that you Have to then isolate the apliance and test again?. ( I will always Isolate first afetr finding a drop btw) Iam genuinly just interested.

Exactly what KIRKGAS was saying; "it don't say you have too". Everyone has their own views on this. Personaly I am not happy to see any drop on the gauge. If I did see the slight drop, I would most likely, if practicble, check it with the appliance iso valves off to make sure and always ask the occupier if they ever smell gas anywhere in the property.

[rickstar88]

Hi Blackcatgas, I didn't say that it says you HAVE to then isolate the appliance and test again,this is just the procedure that i would take..i am just trying to make sure that everyone is aware as 2 engineers i know were not and could of got into bother...

[tamz]

This is why it is important to carry and use testing and purging forms. Record what you are testing and your findings. If a permissable drop is found, it is then at the discretion of the individual operative as to whether or not appliances are then isolated and further tested.

Personally, as most others also, i would isolate and retest but i can see why it may not be done especially by the guys under time pressure on jobs.
Same thing with there being no requirement to do a tightness test when service /repair or doing a landlords cert. It is up to you to make the call.

[rickstar88]

Are you sure you don't have to with a landlord cert,after all it is a gas safety certificate and by not doing a tightness test your not checking that all the gas is safe are you...