I reckon I can detect an occasional, faint whiff of gas around my daughter's kitchen, near the boiler. No other family member can.
Fifty-odd years ago, when I was involved with climbing down manholes, we used a plastic disc containing some sensitive paper to detect gas and make sure it was safe before we entered.
I can't find anything similar now and other detectors seem expensive for one off use.
Short of calling out an expert, can anyone suggest anything?
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Report a leak, presumably a gasman or gaswoman will come with something that can measure it.
If the results are negative, go to the doctors to rule out stroke/brain tumour or similar. I think olfactory hallucinations are common (I get them frequently which can be annoying) but they are sometimes a symptom of brain injury.
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>>
>>
>> If the results are negative, go to the doctors to rule out stroke/brain tumour or
>> similar. I think olfactory hallucinations are common (I get them frequently which can be annoying) but they are sometimes a symptom of brain injury.
>>
That's cheered him up no end.
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>> That's cheered him up no end.
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AND may just save his bacon!
On the same subject we had a problem with Rats entering a property via their own digging, but which was connected to an ancient brick sewer run. The smell of gas was abundant, but a gas leak was not proven. It was the former. Just saying.......
Last edited by: VxFan on Thu 4 May 17 at 01:54
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>> Report a leak, presumably a gasman or gaswoman will come with something that can measure
>> it.
And if they find a leak (pressure drop in the house pipework) they will disconnect the supply, blank off the meter and the supply can only be reconnected when the leak is repaired and the system is proved leak free by a qualified person. They will not repair the leak.
Last edited by: Old Navy on Mon 1 May 17 at 18:41
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I would most definitely report my suspicions.
"And if they find a leak (pressure drop in the house pipework) they will disconnect the supply, blank off the meter and the supply can only be reconnected when the leak is repaired and the system is proved leak free by a qualified person. They will not repair the leak."
So - you would either have the peace of mind of knowing that there wasn't a leak, or the peace of mind knowing that there had been a leak, but it can't cause any damage in the meantime.
Our (independent), qualified boiler-man/plumber detected a leak by pressure testing after he'd installed a new gas boiler in the house. He tracked the (tiny) leak to a recently installed gas-hob in our new kitchen - which I reported to the kitchen company with some indignation.
Our man does a pressure test every year when he comes to service the boiler - last year he found a small leak outside in the meter-box where the gas-pipe leaves the meter. He is exceptionally thorough and would not leave until he'd tracked it down.
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>> >> Report a leak, presumably a gasman or gaswoman will come with something that can measure it.
>>
>> And if they find a leak (pressure drop in the house pipework) they will disconnect the supply, >>blank off the meter and the supply can only be reconnected when the leak is repaired
>> and the system is proved leak free by a qualified person. They will not repair the leak.
>>
Glad I did not call them. I turned off the supply.sawed through the offending steel pipe near a T piece and put a plug in it.
The system has passed all tests since.
The only other leak we had was in our cooker. The gas person thought he was clever, damaged the cooker, stuck a notice on the cooker " Do not use else....) and left us with no cooking facilities.
We had to buy a new cooker.
No cooker made since has a thermostatic control on the gas hob and we were not amused at loosing the feature.!!!
All "experts" inform us that no such feature ever existed. A load of tosh.
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>>I reckon I can detect an occasional, faint whiff of gas around my daughter's kitchen, near the boiler. No other family member can.
I have a proven ability to be able to detect gas when the vast majority of folks cannot.
Do not be put off call the gas mob.
I suspect such a small leak is not a big risk.
( I found a tiny leak in my current house 70/80 years after it was built )
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Report it.
Choose your preferred bad outcome....
Bad Feeling 1: I reported it pointlessly and wasted people's time
Bad Feeling 2: I didn't report it and it went bang.
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If like me you have a sharp nose for that kind of smell then you can detect the tiniest trace of gas even out of doors.
A year ago I levelled a slightly sloping site to build a shed. I excavated about a foot on one side, and detected a vague gassy smell. It's natural methane I suppose, seeping out of disturbed ground from ancient vegetation. It's in open countryside with no mains gas for miles. I still pick up the odd whiff of methane in still air.
Years ago I watched a plumber tracing a small gas smell in the school chemistry lab. He opened all the windows and cupboards etc to vent any pockets, then crawled round following the pipe with a cigarette lighter. At one joint he got a tiny flickery flame about 1/4" high, tightened the joint, and it stopped. He said it was only a risk if the gas built up, but if ventilated then the trace of gas that sensitive noses can detect is harmless. That was then of course, before H&S was invented.
I'd be surprised if a pressure test can detect such a minute leak. Do they turn off the main cock and apply back-pressure with compressed air perhaps? My experience of a failed pressure regulator is that the hob taps pop out if the pressure is too high, because they are tapered seatings held by little springs in the taps.
I'd do some investigating myself first, perhaps not with a lighter, just sniffing around and listening carefully.
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>>I'd be surprised if a pressure test can detect such a minute leak.
>>
IIRC they turn off the supply and attach a gauge to the pipe ( there is a nipple there for such use)
tinyurl.com/kx5ttzq
they then wait for a specific time to see if / how much the gauge drops.
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>> >
>> they then wait for a specific time to see if / how much the gauge
>> drops.
But wouldn't tell them where the leak is though. What do they do next?
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>> But wouldn't tell them where the leak is though. What do they do next?
>>
British Gas would probably switch off the supply, sticker the meter, threaten @@@@ if you touch it and head for the exit. :-((
Someone will have the job of sniffing it out by whatever means.
I am not aware of sniffer dogs for gas leaks.
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">> they then wait for a specific time to see if / how much the gauge drops.
..... But wouldn't tell them where the leak is though. What do they do next?"
I didn't see where our chap plugged the pressure-gauge in, but it was sensitive enough to spot tiny leaks which we had not detected by smell; we were not aware of any problems.
He located the leaks by spraying an aerosol can of something-or-other at all the joints and looking for bubbles. Before he found the one by our gas-meter, he'd clambered across the rubbish-strewn double-garage to follow the pipe as it crossed over the roof trusses.
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>>Years ago I watched a plumber tracing a small gas smell in the school chemistry lab. He opened all the windows and cupboards etc to vent any pockets, then crawled round following the pipe with a cigarette lighter.
I was going to mention that method but thought better ovvit. I've seen it done and would do it myself - with particular regard to mucho ventilation beforehand.
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SFAIK, methane is odourless, hence a stenching agent, mercaptan, is added to piped natural gas. Wiki says the odour threshold is 1 ppb. Marsh gas: anaerobic decomposition with associated, pongy, natural odour! And the will o'the wisp, if you are lucky.
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when our central heating was installed the man tested all his joints with a squirty bottle of soapy water - and then watched for bubbles!
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>>Faint whiff of methane
Methane is odourless. The smell of natural gas is added - so that we can have threads like this.
Gas will only explode if it is a stochiometric mixture - i.e. the ideal ratio such that all the gas is oxidised by air at once. You may recall this experiment at school; it burns with a stead flame until it reaches the stochiometric ratio at which point you have an explosive mixture which will go bang - and blow the lid off the coffee tin.
www.youtube.com/watch?v=cKBsKFLLwYU
For testing joints, a 5:1 water:washing up liquid mixture should work - or pay for 'leak tester' which is the same thing but in a fancy bottle...
Last edited by: Mapmaker on Tue 2 May 17 at 16:06
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or pay for
>> 'leak tester' which is the same thing but in a fancy bottle...
>>
The main one I use is Snoop, something like £5 or £6 for a 300ml bottle.
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I buy our wul in 5L bottles, about £4 each.
Last edited by: Old Navy on Tue 2 May 17 at 17:29
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Quite.
If you want a perfect detonation then by all means organise a stoichiometric mixture (not especially easy) but lean mixtures also go very well - they may combust in a deflagration rather than a detonation (or both, when the deflagration reaches a volume of more combustible mixture) but it can be hard to tell the difference if you are in the middle of it and either can blow the roof off.
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>>either can blow the roof off.
Embarrassing if you were only meant to blow the b***** doors off
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Strictly I think it is incorrect to refer to the "gas exploding". It is the mixture that explodes, and neither air nor methane is explosive if the proportions are outside the range.
If you were an organism living and breathing in methane, then you would be needing a detector to trace small leaks of the explosive gas oxygen.
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>>Gas will only explode if it is a stochiometric mixture - i.e. the ideal ratio such that all the gas is oxidised by air at once.
Not quite...
It will explode if it is in the flammability limit (4.5% to 17.7% by vol in air for methane). Stiochiometric ratio is just for complete combustion to CO2 and water. Too rich and you make CO or carbon black, too lean and you have excess oxygen left over. This is what the Lambda is measuring when they test petrol car emissions. The gas coming out of the tin burns because it is lighter than air, and mixes with the air to be in the flammable range - that in the tin is initially above the flammable range (Too rich) so doesn't burn; when it reaches the UFL then it goes bang (at which point it is still rich, so probably produces black soot in the tin).
By the time you got to 4.5% the stench would be overpowering and you would want to leave the building. The stenching agent is exceptionally smelly!
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Problem solved.
Daughter admitted she also got a whiff of something now and then and bought a gas detector, which detected nothing.
She looked around and wondered about the pot of basil on the windowsill, removed it and odour went.
Does basil smell anything like gas?
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Basil smells of... well basil. Nothing like the odour they add to natural gas we get pumped to our homes.
Last edited by: rtj70 on Sun 7 May 17 at 22:47
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Have you never smelt basil BT? The kng of herbs!
No , it smell like basil and is very fragrant and goes particularly well with tomatoes
Natural gas has Ethyl Mercaptan added to it to give it that distinctive rotting cabbage odour.
Referred to as a "stenching agent" which I like.
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Fresh basil is one of my favourite fresh herbs. Coriander too.
Try to plan it so when I get a pack of fresh basil it goes in some tuna Niçoise sandwiches (found recipe online) and a gnocchi ragu. Tend not to buy pots... probably should.
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Gas detectors - Manatee
