Tightness testing on gas installations

[Scott_D]

As said above
Always test before starting any work so you know what you are dealing with.

 

[Funky dog]

Hello. First of all I’m new to this site. I’m in the process of doing my apprenticeship, but now with the current circumstances we are not working. I have a couple of basic questions which no doubt will raise eyebrows, but every body starts somewhere.

In tightness testing. Regarding permissible drops. It outlines new installations and existing installations.. so what would an installation be if it was a partial upgrade. So half existing/half new

in let by. We are testing to see if the ECV is letting by and rising on the gauge. But if there’s an ever so slight constant drop. That would suggest a leak. So what do you do then, if say the tightness test was satisfactory, 1mbar drop over 2 minutes on an E6?

Apologies for the silly questions. But I keep getting told conflicting information and the book doesn’t actually cover everything

thanks

If you have upgraded a installation treat it as a new no drop

if it’s not letting by go on to stabilisation and tightness test and see how much it’s dropping by then resolve the leak.

 

[GrahamM]

Thanks everyone for the feedback. Great to hear other opinions.

Today we installed a new gas pipe, where eon had capped the meter off for a 3mbar leak on another e6. Not sure why or if gas was smelt. He renewed the gas pipe, only a 3 meter run, feeding one hob.

tightness test showed a 0.15mbar drop on tightness testing. It’s the first time I have seen digital being used. it’s always been a u-gauge before where you would not see that movement. He signed it off and said that was ok.

Guess with things close to the mark it’s a game of opinions?

Perceptible movement is 0.2mb on a digital gauge so your 0.15 drop is within these limits so not an issue.
Dont like using digital gauges anyway. Especially on a windy day as bounces around too much!
Cant beat the Regin Premier when got a full day of CP12's.

 

[sammathias]

Haven't read everyone's replies but I'll stick my 2p in anyway. New installation you shouldn't have any drop on pipework. If I was to be doing a service for instance on an existing installation and I've got a 2mb drop on say an e6 meter before and after service then it's simply noted on the cp12...unless there's a smell of gas.... The second you start isolating appliances looking for an acceptable drop means you will have to find the source of the drop...not always easy. There's tolerable drops on the different types of meters for a reason.
I've had a letby test rise by 0.6mb so thought the ecv was letting by so ldf the ball itself and it was fine. Turnt out to be heat transfer from the sun onto the external pipe run.
Another good senario.....you are replacing a combi....only appliance on existing gas supply. Tightness before work starts and you have 2mb drop. So you change boiler and you still have 2mb drop.....clearly thats indication there is a 2mb leak on pipework that needs looking at, a few I debated this with seemed to think because the pipework installation is existing and there was no smell of gas it's fine and just noted....that would be the case if say they had a gas hob and fire on the install.