tightness testing

Discussion in 'Plumbing and Central Heating' started by lion08, 9 May 2011.

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  1. expertgasman

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    It would make more sense to remove the union of the ECV and test the ECV with LDF. If every installation had an anaconda, I suspect this would be the regs. If an existing leak was PRECISELY the same as the let by rate, no leak or let by would be apparent. If you see what I mean.

    Once again, I suspect that I shouldn't post after an evening on Tim Taylors.
     
  2. bengasman

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    That is new to me. I thought only mp meters lock out.
     
  3. hansthebear

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  4. bengasman

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    Of course, force of habit. :)
     
  5. Jake1886

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    1 minute at 10mbar to test if the ECV (emergency control valve) is letting by.
    1 minute at 20mbar temp stabilization.
    2 minute at 20mbar tightness test of the gas installation.

    Out of interest lion08 which college will you be going too?
     
  6. adlplumbing

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    according to transco guy i know he says it can lock out after 18mb
    thats why we spray the ecv pipe work to governor and governor it self
     
  7. ChrisR

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    The figures for the allowances were worked out from the amount of energy build-up you would get if there were an escape. It used to be part of BG's extended remit to get stuff like that tested, back in the day.
    Anyone remember 20.75mbar test pressure?!
    So no they aren't exactly arbitrary, which is why they're different for different meter & pipe sizes. If you work it all out, the domestic test turns out to be quite a strict one., though it doesn't seem that way when you watch an E6 drop 7mbar and have to decide what to do!
    I find that only about 25% of reassessing rgis know enough about tightness testing and gas rates, which is pretty damning. I don't mean not knowing all the numbers, they can be looked up, I mean not knowing what the numbers depend on. Normally we ask enough leading questions that they work it out.
    We had one guy, an old git like me, who said he did a combined let-by and tightness at 15mbar or so, and that was good enough. I asked him 3 times, same answer. That'll be a FAIL then :rolleyes: . He protested that I'd stopped him working. Yup, that's the idea, mate.

    I didn't know it could be 18, but he's probably right. They can also lock up if the gas goes backwards.
    I know the book says to spray the anaconda, but I protest, cos I've been caught out a couple of times! If eg the anaconda gets flux on it, it'll split, and the gas pours out. So you faff about trying to get your 20mbar, until you lock the thing up. Release the gas slowly and stop at 20mbar, it stays locked up and you do your test. Ok so now you spray the anaconda. But all the gas WENT half a minute ago, through the gert big split, so you see nothing. Of course it stinks, but you've had the test point open, so that's normal.
    Even if you're quick, the rate the gas comes through the split is so high it just blows the LDF out of the way - no bubbles. You have to go up and down the anaconda with a handlful; of LDF, with the gas on. Then you'll either see bubbles at the end of your grip, or you'll feel it, it''ll be COLD!

    Just in case any diyer is wondering - no this is NOT enough information to check for escapes - don't even think about doing it yourself.
     
  8. Agile

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    Insomnia Chris?
     
  9. commercialman

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    Did you know getting old is frowned upon when working in the gas industry? , some would say you're past the sell by date. :mrgreen:
     
  10. bengasman

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    :eek:
    I'll admit that I still have to double check which calculation is for what when it comes to net and gross derivation from a meter reading, but it is shocking that there are guys out there that don't understand how to do the basic tests.
     
  11. namsag

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    as basic as it gets and already up to 3 pages in combustion chamber. tut tut
     
  12. commercialman

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    :eek: :mrgreen: ....................might join the idiot sorry combustion chamber again if not for a laugh.....................
     
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  13. commercialman

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    Namsag , i thought you disbanded from the combustion chamber?
     
  14. namsag

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    Na i read it and according to some i post under 6 different names in it ;)
     
  15. LeeC

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    It's bloody embarrassing.
     
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