Pressure drop on G4

[psk]

Hello wisemen,

I have a little problem on this installation i went on to do a cp12. i found a pressure drop that was over the permissible limits.
basically its a G4 meter connected to a boiler in 22mm and 15mm to cooker and i found a drop over 4mbar. the pressure kept on dropping slowly over a 3-4 min time. i tested several times on 2 mins to be sure there was an actual drop. after i went over 2 mins to observe the drop.
i also disconnected the appliances and tested the pipework only,we are looking at about 3 metres of pipework run and i still found a drop in the pipework. tested all the joints and fittings with ldf but no leaks! though the pressure kept dropping.

has anyone come across such a situation, i will appreciate your inputs in this matter. Its baffled me and i hope you can help me on this matter.

thanks fellows.

 

[AlexGas]

Have you sprayed the tails on the meter?

 

[aggis]

Hi, did you bubble the inlet annaconda & regulator, also disconnect meter outlet & test meter.

 

[anz]

Put a cap on the outlet of the meter and test. If you've still a drop ring National Grid as it's their problem.

Also check your tube just in case.

 

[psk]

yes i bubbled aslmost all the joints i could see. i havnt checked the meter alone. Is there a possibility of the meter leaking? if yes from where? just curious to know.
cheers

 

[mfgs]

Check your monometer and hose for leaks.

 

[tamz]

:iagree:

 

[psk]

as we r speaking i have blowed into the manometer on 20 and held the pressure,its ok

 

[mfgs]

Check the hose for splits, cracks etc. I got caught out by a split before, wasted about 15 mins before I found it. Now its the first thing I check lol.

 

[tamz]

Check the hose carefully. They get small holes in them after a while. Cut an inch off the hose.

 

[psk]

ok thx will keep checking the hose, any other possibilties we looking at leaks in installation?

 

[AlexGas]

Neighbor's connected to the same pipework?!

 

[Leadbetter]

I have had the old split in the hose problem had me confused for an hour hahaha

 

[steadyon]

Is there a capped off point, e.g. for a gas fire. I had one recently which was leaking very slowly through the plug in the restrictor elbow. Could be stopped by tightening the internal valve in the elbow right down, but in the end capped off completely under floor.

 

[kirkgas]

ok thx will keep checking the hose, any other possibilties we looking at leaks in installation?

check if the test point housing is welded or screwed in, if screwed in it could have been disturbed when you unscrewed the test point, as others have said, if you find a drop then test pipe only, next thing is to cap meter outlet and check it, then you know it is on the pipe you need to try to work out the best way to sectionalise (is that a real word) the pipework to trace the drop, have you checked EVERY room and confirmed there are no appliances with pilots on them which are showing up as a leak (i know only an idiot would start tracing for a leak after missing an old fire in an upstairs room), i (i mean a guy i know) was gutted/happy when i found the fire and realised there was no leak

 

[metaldust9]

ad check the anaconda pipe /flexi pipe on the meter as i had a pin hole in one and it leaked, down to flux being dropped on it from someone else and i had the same simtomes

 

[stevetheplumber]

after all above its a case of cutting and capping to get in sections to test individually

 

[diamondgas]

Hello wisemen,

I have a little problem on this installation i went on to do a cp12. i found a pressure drop that was over the permissible limits.
basically its a G4 meter connected to a boiler in 22mm and 15mm to cooker and i found a drop over 4mbar. the pressure kept on dropping slowly over a 3-4 min time. i tested several times on 2 mins to be sure there was an actual drop. after i went over 2 mins to observe the drop.
i also disconnected the appliances and tested the pipework only,we are looking at about 3 metres of pipework run and i still found a drop in the pipework. tested all the joints and fittings with ldf but no leaks! though the pressure kept dropping.

has anyone come across such a situation, i will appreciate your inputs in this matter. Its baffled me and i hope you can help me on this matter.

thanks fellows.

How much over the 4mbar are we talking psk? You have a very small amount of pipe so 5mbar is a pretty small leak! Do you know anyone with a gas detector? ldf has it's limits! As long as you know it's not on your manometer and not the gas meter then it's either a re-pipe or trace and repair. Another obvious question is to ask the tenant if they've smelt gas anywhere?

ANyhoo's they're my thoughts ...

 

[midge]

That brings back bad memories of the day I cut off three customers in a row before discovering a pin hole in my U gauge rubber tube.

 

[psk]

well its keeps dropping steadily and no the customer hasnt smelt any gas neither did i. i do not know anyone with a gas detector so im just stuck with my ldf lol.

 

[psk]

its aw welded joint and it looks sound. i will try testing the meter alone. never heard of a meter leaking:confused5:, if it is the meter then where from? i will probably call the gas board out.
thanks for the input gentlemen it is an eye opener when everyone pitches in. much appreciated

 

[diamondgas]

That brings back bad memories of the day I cut off three customers in a row before discovering a pin hole in my U gauge rubber tube.

I remember a guy I knew at BG spent all day exchanging sunken meters on a housing estate only to realise later that evening that he had a test nipple in his pocket!!! LOL Armed with a torch that evening he drove back to the estate, jobsheet in hand lifting the covers of the meters until he found the one ... !!

 

[AWheating]

you could always air test pipework. Higher pressure = better chance of tracing a leak with your ldf.

 

[Billy Bob Bob]

its aw welded joint and it looks sound. i will try testing the meter alone. never heard of a meter leaking:confused5:, if it is the meter then where from? i will probably call the gas board out.
thanks for the input gentlemen it is an eye opener when everyone pitches in. much appreciated

in my time i have had 3 meters leak dont dis credit it it does happen obviously check your hose to your gauge first

 

[That Extra Mile]

We've found gas leak detectors really useful in these situations. They're not that cheap but are very sensitive and will pick up the smallest leaks quickly. In our experience they're much more effective than leak detection spray. Jonathan, That Extra Mile Plumbing.

 

[Kimou]

you could always air test pipework. Higher pressure = better chance of tracing a leak with your ldf.

You don't mean compressing the system with just air do you?

 

[AWheating]

You don't mean compressing the system with just air do you?

sticking on of thoses regin test pump tee and pumping the pressure up above 20mb and you will have a better chance of finding a leak with ldf, wouldnt advise a high pressure of course.

 

[Kimou]

haha, no that wouldn't be the sanest thing to do. Even still. I wouldn't tell anybody about it. But I suppose if there was an explosion then it'd happen there and then. You have to carry out a RA and get everyone out the building before you do one and only if you're trained. Scary what can happen. I was going to do that years ago when I was very young but couldn't be bothered to get my friend's compressor... Can you imagine???

 

[psk]

i reckon i will have to invest in one of these after my experience with tihs leaky situation.
what figures we looking at?

btw everyone thanks for your input.ta

 

[Pssst]

Are you qualified? this is hardly rocket science.

 

[psk]

Occluded I'm qualified and if it would have been rocket science u wouldn't be able to answer it either it doesn't hurt asking a question just to confirm ur findings. Now this isn't rocket science isn't it?