Discuss 0.5mb drop on tightness test - Should I be worried? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

they would say its within safe limits why did you go looking for the leak when you didnt need too
Agreed, there almost certainly isn't a leak, and none within the meaning of the regs. No system would be totally leak free - if you left it for a year the pressure would fall. As others have said, change of temperature could easily cause that sort of pressure change. A fall of about 0.15°C is all it needs for the pressure to fall by 0.5mb.
 
we don’t use steel for gas pipes in domestic properties. The permissible drop is to cater for old gas valves on appliances, pipework only has to be totally tight.
How come, I come across quite often steel gas pipes which are either under the floor connected to copper or bedded in concrete? However, the point I made is to check for weaknesses and cracks which could be hidden due to slag or other debris.
 

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How come, I come across quite often steel gas pipes which are either under the floor connected to copper or bedded in concrete? However, the point I made is to check for weaknesses and cracks which could be hidden due to slag or other debris.

you test at op and thats it
 
A domestic gas installation should be tested at 1 bar for 30 mins ?
Standing pressure is usually well below 30mbar and working pressure 21 +\-2 so probably a bit overkill.
I do agree with zero tolerance though, that’s alway what I aim for anyway even if it’s within permissible drop.
Overkill ? Sorry mate but I disagree with that term. A gas pipe should be tested with a lot higher pressure than just 30mbar. You have to check the pipe under a load test which means with higher pressure than the one you will have when the pipe is in use. You will test the material and joints for weaknesses , hairline cracks or pinholes which are covered by slag. Due to the higher pressure you make sure to find those weaknesses or cracks which you won’t find by mbar.
 
Overkill ? Sorry mate but I disagree with that term. A gas pipe should be tested with a lot higher pressure than just 30mbar. You have to check the pipe under a load test which means with higher pressure than the one you will have when the pipe is in use. You will test the material and joints for weaknesses , hairline cracks or pinholes which are covered by slag. Due to the higher pressure you make sure to find those weaknesses or cracks which you won’t find by mbar.

so do you remove the boiler cooker and fires to do the test as these can only take 20 mbar
 
You dont need to do a TT on a service
Unless you
Overkill ? Sorry mate but I disagree with that term. A gas pipe should be tested with a lot higher pressure than just 30mbar. You have to check the pipe under a load test which means with higher pressure than the one you will have when the pipe is in use. You will test the material and joints for weaknesses , hairline cracks or pinholes which are covered by slag. Due to the higher pressure you make sure to find those weaknesses or cracks which you won’t find by mbar.
But the pressure in the pipe is in mbar, we’re only talking about domestic installation pipework with a working pressure of 19-23 mbar and standing pressure usually a few mbar higher than that so why the need to test to 1 bar?
 
so do you remove the boiler cooker and fires to do the test as these can only take 20 mbar
Yes, you would need to otherwise you will ruin the appliances. You can only test them via there operating pressure as you know. But when it comes to testing the pipework throughout the property when installed new then you will need to use the appropriate fittings to cap them off and test them with higher pressure ( but that’s the way we do it in Germany ). We do 2 test before bedding pipes into the concrete, load testing ( 1bar with air or N ) for 30min -1hour and then a 15 min test leak test.

Sorry but it is difficult to explain german terms in English. I think you can’t be careful enough when it comes to gas. I know it’s done differently here and I do whatever is required but I would wish few things would be different.
 
Unless you

But the pressure in the pipe is in mbar, we’re only talking about domestic installation pipework with a working pressure of 19-23 mbar and standing pressure usually a few mbar higher than that so why the need to test to 1 bar?
If I can decipher his posts, I think the gas pipework in his home country is welded and welded joints can be terrible, so it makes sense to test at much higher pressure
 
Unless you

But the pressure in the pipe is in mbar, we’re only talking about domestic installation pipework with a working pressure of 19-23 mbar and standing pressure usually a few mbar higher than that so why the need to test to 1 bar?
We have also 18-25mbar but when it comes to test pipework we have to undertake those tests and get that printed off with a special machine.
 
Yes, you would need to otherwise you will ruin the appliances. You can only test them via there operating pressure as you know. But when it comes to testing the pipework throughout the property when installed new then you will need to use the appropriate fittings to cap them off and test them with higher pressure ( but that’s the way we do it in Germany ). We do 2 test before bedding pipes into the concrete, load testing ( 1bar with air or N ) for 30min -1hour and then a 15 min test leak test.

Sorry but it is difficult to explain german terms in English. I think you can’t be careful enough when it comes to gas. I know it’s done differently here and I do whatever is required but I would wish few things would be different.

dont want to be rude but your / were not in germany doesnt matter what the german standards are there not ours
 
If I can decipher his posts, I think the gas pipework in his home country is welded and welded joints can be terrible, so it makes sense to test at much higher pressure
Yes back in Germany we have steel pipe, malleable pipes, copper pipes which could be welded, screwed or crimped. So I am just trying to say that it would be good if we had 0 tolerances as well as checking pipes slightly different. But as we know it is different in each country. I think you would find much more leaks when pipes are tested with higher pressure and it would just help to rectify the leaks before something horrible happens.
 
dont want to be rude but your / were not in germany doesnt matter what the german standards are there not ours
You aren’t rude. You are quite right and I agree with that. I was just mentioning my own opinion as we had a discussed about zero tolerances. I just tried to explain few more things in depth. But if you understand my point of view I think you would agree with me that I am not so wrong.
 
If I can decipher his posts, I think the gas pipework in his home country is welded and welded joints can be terrible, so it makes sense to test at much higher pressure
welded should be better than any soldered joint!

We should test at 20mb to avoid regulator lockout and not testing pioework the other side of it
 
welded should be better than any soldered joint!

We should test at 20mb to avoid regulator lockout and not testing pioework the other side of it
You are right scott. I know that and that’s you would not be able to test the pipework with higher pressures. You would need to test them without having anything connected. We also check only the downstream side of it
 
welded should be better than any soldered joint!

We should test at 20mb to avoid regulator lockout and not testing pioework the other side of it

Not everyone can weld, lots of people can solder. Soldering is easy... you can pretty heat the front of the fitting and add solder... job done( usually)
Try welding a small pipe with tig/ stick / mig

Different story..

So no, welded joints could potentially leak
 
Not everyone can weld, lots of people can solder. Soldering is easy... you can pretty heat the front of the fitting and add solder... job done( usually)
Try welding a small pipe with tig/ stick / mig

Different story..

So no, welded joints could potentially leak
Agree with you. Welding is practing it comes with time. You will need to do it very regularly to have a good decent weld done which doesn’t leak. Do you actually learn welding in apprenticeships? I remember we had to bend steel pipe with sand, welding joints, soldering copper, brazing, ... using basically all kind of materials and fittings.
 
Different argument but quoting German stats again Ron. One day working to German regs will get you in to trouble. But you know best. Best to leave him to it @ShaunCorbs
You did not get my point harvest. I was saying that I stick to the rules here but would love to see some changes. The above statements are just my opinions nothing more or less. I am not working according to german standards, first of all I don’t have the parts and materials to carry out such a great work which is obviously a downside but it is what it is. It seems like you misunderstand me quite often. It is either down to my English or perhaps my understanding of your language.

So just to clarify, I stick to the rules and regs over here but have a different approach to what is right and wrong. I am just having a different opinion about plumbing in uk and in Germany. Have you ever been to Germany? Perhaps you should give it a go and come to see some of the plumbing events. Next one this year I would like to invite you and show you around if you are up for it
 
You did not get my point harvest. I was saying that I stick to the rules here but would love to see some changes. The above statements are just my opinions nothing more or less. I am not working according to german standards, first of all I don’t have the parts and materials to carry out such a great work which is obviously a downside but it is what it is. It seems like you misunderstand me quite often. It is either down to my English or perhaps my understanding of your language.

So just to clarify, I stick to the rules and regs over here but have a different approach to what is right and wrong. I am just having a different opinion about plumbing in uk and in Germany. Have you ever been to Germany? Perhaps you should give it a go and come to see some of the plumbing events. Next one this year I would like to invite you and show you around if you are up for it

I’ll come, as long as you can buy me some cheap Vw high power race parts, from some of the German engineering companies :D
 
You did not get my point harvest. I was saying that I stick to the rules here but would love to see some changes. The above statements are just my opinions nothing more or less. I am not working according to german standards, first of all I don’t have the parts and materials to carry out such a great work which is obviously a downside but it is what it is. It seems like you misunderstand me quite often. It is either down to my English or perhaps my understanding of your language.

So just to clarify, I stick to the rules and regs over here but have a different approach to what is right and wrong. I am just having a different opinion about plumbing in uk and in Germany. Have you ever been to Germany? Perhaps you should give it a go and come to see some of the plumbing events. Next one this year I would like to invite you and show you around if you are up for it

Well you don’t as you’ve said you test gas carcass at 1 bar which could hide a small leak
 

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