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LPG leak ?


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13 hours ago, DandV said:

Any smell of gas, or imagined smell of gas must be followed up...

At home when I opened the gas meter cupboard door I could smell gas. So out came the engineer. He couldn’t find any point of leakage anywhere using a sniffer so he changed the regulator and flexi simply because he couldn’t think of anything else (and he had one on his van). The next time I opened the door I could smell gas again so a new engineer came out and he replaced the meter. A few weeks later another engineer came out to replace the meter with a smart meter. A couple of weeks after that we had an inspection that flagged up that we only had one earth bonding flag but should have two because the feed to the house went into a T piece within the meter cabinet. I may or may not get around to fitting another bonding connection but at least I can’t smell gas any longer...

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4 hours ago, croftie said:

Wayne, is that regulator damaged? It looks like a dent where the paint is missing, something dropped on it?

No its a blob or primer. It was new when i fitted everything aswell. 

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Ok is is safe to comment now without Sam scribbling all over the thread?

 

You are right. The pressure in a propane system is nominally 37mbar and that manometer is only good for 30mbar.

 

Not sure why Wayne is considering buying a manometer though, as it will only tell him the same as the bubble tester, i.e. that there is a leak. We know that already. The task is to find it. 

 

 

19 hours ago, catweasel said:

Hopefully mtb will comment, but I think the manometer for our job has to be a higher pressure. I will stand corrected if wrong. I copied someone else's and wrote the test procedure on the wooden plate which somebody kindly posted on here. I can measure it if it is any help.

 

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6 minutes ago, Mike the Boilerman said:

 

Ok is is safe to comment now without Sam scribbling all over the thread?

 

You are right. The pressure in a propane system is nominally 37mbar and that manometer is only good for 30mbar.

 

Not sure why Wayne is considering buying a manometer though, as it will only tell him the same as the bubble tester, i.e. that there is a leak. We know that already. The task is to find it. 

 

 

 

Hi Mike, its just for peace on mind to get a monometer to rid the thought of a dodgy Bubble tester. I know its just going through all i can before i bloody rip it ll out and star again lol..

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1 hour ago, W+T said:

Hi Mike, its just for peace on mind to get a monometer to rid the thought of a dodgy Bubble tester. I know its just going through all i can before i bloody rip it ll out and star again lol..

Wayne, I’ve said it before (as have others) and I’ll say it again, if there are bubbles going through the tester these are bubbles of gas and they can only travel through the tester if the gas is going somewhere...

 

You’ve purged all the air out of the pipes by running the appliances, so the gas pressure is constant within the system. With the appliances switched off any flow of gas has to be a leak.

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1 hour ago, Mike the Boilerman said:

 

Ok is is safe to comment now without Sam scribbling all over the thread?

 

You are right. The pressure in a propane system is nominally 37mbar and that manometer is only good for 30mbar.

 

Not sure why Wayne is considering buying a manometer though, as it will only tell him the same as the bubble tester, i.e. that there is a leak. We know that already. The task is to find it. 

 

 

 

Freakin' hell can I frame that?  nobody has ever said that before ;) 

Joking aside, I do seem to remember that the pressures we are dealing with are higher than found in a  domestic "natural gas: situation.

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38 minutes ago, WotEver said:

Wayne, I’ve said it before (as have others) and I’ll say it again, if there are bubbles going through the tester these are bubbles of gas and they can only travel through the tester if the gas is going somewhere...

 

You’ve purged all the air out of the pipes by running the appliances, so the gas pressure is constant within the system. With the appliances switched off any flow of gas has to be a leak.

 

Seconded.

 

And even if he hadn't purged all the air, the pressure would still be the same everywhere in the system (with no appliances running). So that's another poisson rouge...

 

 

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49 minutes ago, WotEver said:

Wayne, I’ve said it before (as have others) and I’ll say it again, if there are bubbles going through the tester these are bubbles of gas and they can only travel through the tester if the gas is going somewhere...

 

You’ve purged all the air out of the pipes by running the appliances, so the gas pressure is constant within the system. With the appliances switched off any flow of gas has to be a leak.

.............  unless the regulator is not managing to keep the pressure constant and is allowing the downstream pressure to slowly increase in the piping to the isolation valves.   in such a case the tester will show gas passing when the isolation valves are opened. 

Edited by Murflynn
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9 minutes ago, Murflynn said:

.............  unless the regulator is not managing to keep the pressure constant and is allowing the downstream pressure to slowly increase in the piping to the isolation valves.   in such a case the tester will show gas passing when the isolation valves are opened. 

When you put it like that, it could be what was happening with my system.  I like your thinking.

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3 hours ago, Murflynn said:

.............  unless the regulator is not managing to keep the pressure constant and is allowing the downstream pressure to slowly increase in the piping to the isolation valves.   in such a case the tester will show gas passing when the isolation valves are opened. 

 

True!

 

In which case a manometer connected to the test nipple will show a steadily rising pressure. 

 

This is one of the reasons the first step in using a manometer for tightness testing is the let-by test. No-one ever mentions this on here, except me :)  

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20 hours ago, Mike the Boilerman said:

 

True!

 

In which case a manometer connected to the test nipple will show a steadily rising pressure. 

 

This is one of the reasons the first step in using a manometer for tightness testing is the let-by test. No-one ever mentions this on here, except me :)  

Is this the part where you lower the pressure in the system and watch for any rise? I cant' remember as I don't do such stuff very often. 

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I could tell you exactly how to use a manometer correctly, it would not tell you lies.

But I am not going to have the old  Knows all about nowt boiler spew all over my threads like he does with Sam, who really seems to know what is what. Where is Sam?

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7 minutes ago, hider said:

I could tell you exactly how to use a manometer correctly, it would not tell you lies.

But I am not going to have the old  Knows all about nowt boiler spew all over my threads like he does with Sam, who really seems to know what is what. Where is Sam?

I'm sure he's around somewhere 

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Okey dokey

 

Here goes. All i did was fit a test nipple on the valve body so before the valves/taps themselves. 

 

I tested for that  to see if leaking and all good :)

 

Now i tested the lines, dont know why but i thought i would see whats happening now. As said before the bubbles in the tester do change. 

 

When i open each line there is a bubble straight away but nothing for over a minute. The same when i open all three lines/valves together. One bubble then nothing for over a minute.

 

I checked the cylinder regulator for bubbles in the small release hole on top, nothing either.

 

So guys n gals what does that mean.

 

Either a dodgy bubble tester or maybe reg ? all i can think of.

 

I am getting manometer this weekend and see what that does.

 

 

Captain Faffer :)

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42 minutes ago, W+T said:

Okey dokey

 

Here goes. All i did was fit a test nipple on the valve body so before the valves/taps themselves. 

 

I tested for that  to see if leaking and all good :)

 

Now i tested the lines, dont know why but i thought i would see whats happening now. As said before the bubbles in the tester do change. 

 

When i open each line there is a bubble straight away but nothing for over a minute. The same when i open all three lines/valves together. One bubble then nothing for over a minute.

 

I checked the cylinder regulator for bubbles in the small release hole on top, nothing either.

 

So guys n gals what does that mean.

 

Either a dodgy bubble tester or maybe reg ? all i can think of.

 

I am getting manometer this weekend and see what that does.

 

 

Captain Faffer :)

my bet is on the regulator - it ain't leaking externally but it isn't holding back the bottle pressure properly.

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Just now, Murflynn said:

my bet is on the regulator - it ain't leaking externally but it isn't holding back the bottle pressure properly.

I agree, but, as always with me lol. How come the bubble tester dont bubble when the valves are closed the gas can get to the valve body?

 

Is it the lines that are longer to take more pressure/gas so makes the first bubbles ?

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3 minutes ago, W+T said:

Is it the lines that are longer to take more pressure/gas so makes the first bubbles ?

That’s Murf’s guess, yes. There’s a length of pipe to pressurise over time once a tap is open. With the tap closed there’s insufficient pipe after the bubble tester for the problem to show. 

 

So if it turns out that the regulator is faulty then it’s also shown that the bubble tester flagged up the fault. 

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1 minute ago, WotEver said:

That’s Murf’s guess, yes. There’s a length of pipe to pressurise over time once a tap is open. With the tap closed there’s insufficient pipe after the bubble tester for the problem to show. 

 

So if it turns out that the regulator is faulty then it’s also shown that the bubble tester flagged up the fault. 

Going to get a reg tomorrow so fingers crossed.

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good luck

1 hour ago, WotEver said:

That’s Murf’s guess, yes. There’s a length of pipe to pressurise over time once a tap is open. With the tap closed there’s insufficient pipe after the bubble tester for the problem to show. 

 

So if it turns out that the regulator is faulty then it’s also shown that the bubble tester flagged up the fault. 

exactly.  the volume inside the pipe from the tester to the isolation valve is insignificant so there would be little movement of gas responding to a slight change in pressure..

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