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Bubble Tester Question


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6 hours ago, nicknorman said:

Interesting that the tightness test is done at a significantly lower pressure than the operating pressure. 20mB vs 37 mb. Seems odd!

 

It is odd I agree, but I think it is to do with the rate gas leaks through a small hole in relation to the pressure causing that flow. The quantity of gas that needs to be stuffed into the space behind the hole makes a difference! 

 

Remember that member we once had who dismissed out of hand testing at 20 mBar, or 37 mBar or anything like it? He pumped up his gas installation to 2.0 Bar and if the gauge still said 2.0 Bar the next morning, he considered this proof the system was gas tight. See any problems with that?? 

 

 

 

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2 minutes ago, Mike the Boilerman said:

Remember that member we once had who dismissed out of hand testing at 20 mBar, or 37 mBar or anything like it? He pumped up his gas installation to 2.0 Bar and if the gauge still said 2.0 Bar the next morning, he considered this proof the system was gas tight. See any problems with that?? 

He is no longer with us ?

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4 hours ago, bizzard said:

An ordinary little test point for a manometer is only a fraction of the price of a bubble tester which are nearly £50 plus installation, and get yourself a BSS inspector that is Boat gas safe registered.

That can be difficult. Where I am, none of the local BSS Inspectors are Gas safe registered. We managed to track down a "Gas Safe for boats " registered guy, but he said he only did the "boats" part of the course because he fancied another day away, and having lashed out for the "domestic" course (required for the LPG course),the LPG course (required for the "caravan" course), and the "caravan" course, the "boats" course wasn't a lot more money. His normal job was gas in caravams.

Our options for the BSS on a trip boat were either arrange for both the gas guy and the BSS guy to be there at the same time, or fit a bubble tester. The former proved impossible, as neither could guarantee a time, both having other other commitments which took priority. We fitted a bubble tester :).

 

The local hire fleet(s) "import" a BSS Inspector every couple of years, and pay his travel and hotel expenses.

Edited by Iain_S
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12 hours ago, system 4-50 said:

Alde bubble testers are available adapted to imperial (which is difficult to do yourself). I got mine from Socal. I think they might do other sizes to order? I thought I bought 5/8ths but I might be wrong.

https://www.socal.co.uk/search/bubble

 

It's very simple to change the fitting and olive to imperial, you simply put the bubble tester in a vice and crack the original metric fitting off. Where does this myth come from that anything to do with gas is difficult to do?

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3 minutes ago, blackrose said:

 

It's very simple to change the fitting and olive to imperial, you simply put the bubble tester in a vice and crack the original metric fitting off. Where does this myth come from that anything to do with gas is difficult to do?

Because in the past the thread sealant that is used is more like a permanent thread lock and it feels something will catastrophically break before the sealant lets go.

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9 hours ago, Mike the Boilerman said:

 

I promise you, it isn't. 

 

The fact that your statement overlooks flueing and ventilation illustrates just how incompetent you are.

 

 

Well well just have to agree to disagree. I wasn't talking about fluing or ventilation, just plumbing. Is that really the best argument you can come up with (again)? The fact that you bring up flueing and ventilation again to try to justify your position like you did last time we talked about this, just illustrates how pig headed and ignorant you are. 

 

By the way, the flueing and ventilation of my gas appliances (where relevant) was also passed by all inspectors with flying colours so they certainly didn't agree with your verdict about my competence and unlike you they actually inspected the boat! ?

Edited by blackrose
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6 minutes ago, blackrose said:

 

It's very simple to change the fitting and olive to imperial, you simply put the bubble tester in a vice and crack the original metric fitting off. Where does this myth come from that anything to do with gas is difficult to do?

It is not that it is related to gas, its just that the metric fittings are in very tight. With the right equipment (I have no vice(s)) I'm sure it is straightforward.

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6 hours ago, Tacet said:

I have had a quick Google (I know), and it looks to me as though the regulations apply to boats in which the owner/user lives for most of the time.  If this is correct, then it is not a question of no-other-abode liveaboard (or not).

 

Someone may well know better than me - but over what period is "most of the time" measured?  Maybe its a year, which seems reasonable  But if one takes Nick's summer,  he may well live on his boat most of the time.   On the other hand you could take a much longer period of several years and come to a different conclusion even if you lived aboard for one calendar year.

 

 

 

6 hours ago, Alan de Enfield said:

It is a residential boat if it is your sole, or main, residence.

 

It could be argued that at 6 months and 1 day on board it becomes you main residence.

 

However :

 

CODNER v WILTSHIRE VALUATION AND COMMUNITY CHARGE TRIBUNAL (1994)

The High Court confirmed the principle that time was not the only factor to be considered in determining sole or main residence.

 

The courts use the following as indicators of main residence :

 

Personal Ties
 

  • At which residence you are registered with a doctor / dentist
  • Where the majority of your possessions are kept
  • Where you return to during periods of leave or at the end of employment
  • Your long-term intentions
  • Are you already regarded as mainly resident elsewhere for council tax purposes
  • Where you are registered to vote
  • Membership of clubs and other social activities  
  • Where you receive post
  • Which property you regard as your main residence
  • How you split your time between your residences


Family Ties
 

  • At which residence your partner / dependants live
  • From which residence your children attend school
  • At which residence you spend time with your family    

 

 

I was looking at this http://www.hse.gov.uk/pUbns/priced/l56.pdf which refers to "most of the time" rather than "main residence"  Is the latter determinative for Gas Safety as well as the now defunct Community Charge?

 

Even so, I can't see why 6 months and 1 day is a watershed.  Surely a boat can be you main residence from the moment you step on it, in some circumstances at least.

 

6 hours ago, nicknorman said:

This is what the exemption to the law actually says:

 

5) Nothing in these Regulations shall apply in relation to the supply of gas to, or anything done in respect of a gas fitting on—

...

c)a vessel not requiring a national or international load line certificate except when such vessel is—

(i)hired out in the course of a business;

(ii)made available to members of the public in the course of a business carried out from that vessel; or

(iii)used primarily for domestic or residential purposes;

 

So it is (iii) that is relevant. But what does it mean? Well the industry has decided that it means live aboard vs not live aboard. Personally I’d say that all leisure Narrowboats are used primarily for domestic or residential purposes even if only for 2 weeks a year. The rest of the time (when the owners are not aboard) the boat is not used at all. What else are they used for? 

This looks to be chapter and verse. The interpretations that you and the industry both offer sound plausible but (against you)  it is reasonably possible that the primary use of a boat is for holiday rather than domestic (or residential) purposes.  Who knows.  And, of course, how long is a holiday use before it becomes residential use?   I lived aboard for three years and it felt little different from a long holiday.  It is likely that some of the considerations in Alan 'de' Enfield's community charge case might be relevant - such as does one have alternative accommodation readily available and, perhaps, whether you go to work each day.  The amount of travel by the boat could be a factor too

Edited by Tacet
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1 hour ago, blackrose said:

It's very simple to change the fitting and olive to imperial, you simply put the bubble tester in a vice and crack the original metric fitting off.

 

Changed my mind.

 

Edited by Mike the Boilerman
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On 09/11/2019 at 15:44, alan_fincher said:

So is this actually an issue if appliances are simultaneously in use at more than 12KW.

 

Yes, because there will be a pressure drop through the bubble tester causing a pressure drop higher than allowable under PD54821-3 (or whatever it is called this week.) An abnormally low burner pressure when all the appliances are connected and running could be dangerous, apparently, as the appliances are no longer being operated in accordance with manufacturer specifications. 

 

 

Edited by Mike the Boilerman
Terminology error!
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2 hours ago, Mike the Boilerman said:

 

Yes, because there will be a pressure drop through the bubble tester causing a pressure drop higher than allowable under PD54821-3 (or whatever it is called this week.) An abnormally low burner pressure when all the appliances are connected and running could be dangerous, apparently, as the appliances are no longer being operated in accordance with manufacturer specifications. 

 

 

The BSS examiner poster whose thread was expunged said that low gas pressure can result in increased CO output. Is that right? Seems a bit counter-intuitive because normally CO is produced when there is too much gas and not enough air.

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12 hours ago, nicknorman said:

The BSS examiner poster whose thread was expunged said that low gas pressure can result in increased CO output. Is that right? Seems a bit counter-intuitive because normally CO is produced when there is too much gas and not enough air.

From my days as a student testing industrial gas burners...

Too much gas and you get CO due to incomplete combustion. Too much air and you get CO due to the flame being quenched before combustion is complete. That was on forced draft burners (fan driven air supply) and the same may not happen on natural draft burners such as cookers.

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5 minutes ago, David Mack said:

From my days as a student testing industrial gas burners...

Too much gas and you get CO due to incomplete combustion. Too much air and you get CO due to the flame being quenched before combustion is complete. That was on forced draft burners (fan driven air supply) and the same may not happen on natural draft burners such as cookers.

With burners designed for variable flame (hob, grill, oven) I can’t see how having a reduced gas pressure is any different from turning the flame down using the knob or thermostat. For a fixed flame device like a Morco I suppose it could be different, but I’m struggling to see how!

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32 minutes ago, nicknorman said:

With burners designed for variable flame (hob, grill, oven) I can’t see how having a reduced gas pressure is any different from turning the flame down using the knob or thermostat. For a fixed flame device like a Morco I suppose it could be different, but I’m struggling to see how!

 

Nor me.

 

Even the Morco isn't fixed flame. It has high and low flame settings.

 

The training we get on CO as lowly gas bods always strikes me as heavily dumbed down, as you can imagine how feek some of the plumbers there are, and they HAVE to squeeze them through or the skool gets a reputation for failing peeps and commercially fails as word gets around. 

 

So I'm in no position to answer any of the more probing questions that might crop up, I've just been fed the company line where CO is concerned...

 

 

 

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Just now, Machpoint005 said:

 

Please Sir, how could he read to a fraction of a millibar on a gauge reading up to 2bar (or more)?

Well yes but I think it’s more to do with the maximum pressure that a typical gas solenoid valve can tolerate. Much less than 2 bar!

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1 hour ago, nicknorman said:

With burners designed for variable flame (hob, grill, oven) I can’t see how having a reduced gas pressure is any different from turning the flame down using the knob or thermostat. For a fixed flame device like a Morco I suppose it could be different, but I’m struggling to see how!

I'm inclined to agree. The burners I tested had metred quantities of gas and air, so the air/gas ratio was fixed. Natural draft burners essentially use as much air as is needed for the quantity of gas supplied.

Turning down the knob results in a lower gas flow, and hence a reduced pressure behind the nozzle, exactly the same as reducing the supply pressure further upstream would.

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1 hour ago, Mike the Boilerman said:

 

 

 

So I'm in no position to answer any of the more probing questions that might crop up, I've just been fed the company line where CO is concerned...

 

 

 

Which is what they will use if ever the shit hits the fan

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