In article ,
Fredxxx writes:
On 07/05/2015 13:39, Martin Bonner wrote:
On Thursday, 7 May 2015 13:34:35 UTC+1, newshound wrote:
On 07/05/2015 13:03, Jim GM4DHJ ... wrote:
"Fredxxx" wrote in message
...

Its easy to detect gas leaks with a simple manometer.

It is quite easy, but there is a defined procedure which is not
obvious if you don't already know it.

If any doubts get a Landlord or similar gas safety certificate.

you can do that at the connector at the meter can't you ? ......

At the test nipple.
Afterwards you should check the test nipple is sealed closed by using
leak detector fluid.

Correct. I forget the pressure drop criterion, isn't it something like
less than 10 mm in five minutes (which is about 1 mb) for a typical
domestic installation?

Or "no detectable drop" if all the appliances have been disconnected.

There is also the small proviso that the regulator hasn't kicked in and
regulating the high pressure gas between the lever valve and regulator.

In other words you should ensure the starting pressure is a little below
this 'regulated' pressure to ensure the lack of any drop isn't caused by
this.

You also have to check that the main stop cock is sealing off, which
you do by closing it, safely venting the pipework down to atmospheric
pressure and then closing off the vent point, and monitor the pressure
for a while to make sure the pressure doesn't start increasing in the
pipework. If the main stop cock is not sealing off, it can hide a leak
in the system during the pressure drop test.

Note that you do these tests before *and* after making changes. If you
only check afterwards and find a leak, you will not know if you caused
it or if it was already there, which makes a big difference to the
fault area which needs searching.

Second note - ambient temperature changes during a pressure test will
cause the pressure in the pipework to change even when there aren't
any leaks.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]