Just had an argument about tightness testing

[Ryster]

Second post in as many days.
Just been in plumb centre and was earwigging on two guys talking about testing.
Now I'm a commercial fitter with domestic as well. Granted I have not used my domestic that much over the years but it does get used.

Now the way I was taught was the following;

Upon entering a building to do gas work you do the following:
1 minute let-by at 10mbar
1 minute stabilisation at 20mbar keeping at 20 for that minute
2 minutes at 20mbar.
Anything above 75mbar is medium pressure and requires a different test (this was where I got into conversation with them as they said anything over 82.5 was medium)

Any Drops at stabilisation are fine, any drops within 2 minute test need to be within permitted limit otherwise test fail and you need to find the source

You then do any work IE boiler service, then after the work do the same again.

Now these two guys argued with me for five minutes that you do only need to do a 2 minute test at 20mbar.
Any drop is fine as long as there is no smell of gas.
Also that doing a test upon entry is not needed, and I was wasting my time.

Now somebody please tell me I'm right, I don't have my domestic viper with Me so cannot check, but I will be mortified if I have been doing it wrong all these years!

Honestly these lads have put complete doubt in my mind now, to the point that I'm worried about doing a test today!

 

[AWheating]

you must perform a tightness before touching any part of the gas installation to make sure you have not caused a leak yourself. for example you test and find a 2mb drop, then carry out your work, test again and you have a 3mb drop. Something you have done may have caused the extra drop and will need checking.

If you dont perform the first test then you cant be sure of your own work being correct, and also if you dont test first and it has a drop outside the allowable limits then you will be responsible for finding the problem im my eyes.

It takes 3-4 mins to do a correct tightness test, i cant see what you will save by not doing one?

 

[mickie]

any drop isnt fine even if you cant smell it, on pipework.. appliances depends on the meter

 

[AWheating]

basically the guys you argued with were idiots and dangerous to boot.

 

[Ryster]

So i was right then.

I hate ****s like this, they were so cock sure about what they were doing it put doubt in my mind about the process I use.

 

[leelister6]

Sound like the sort of tossers I used to see in Plumb Centers all the time before I stopped using em; Snickers work trousers (Regulation bright blue), Walk straight round counter like they own the place and get their gear from the back themselves, rest beer gut on counter while drinking free coffee and telling everyone that will listen that "They're pulled out with work, aint had a day off since 1976, fitted 2 full systems since 8 this morning and still got another 3 to fit before 4 o clock & I don't need to do a tightness test cos I'm the bestest fastest gas fitter in (Insert the town/city of your choice)!" I always do a test before and after every job cos to be honest, I'm just too pretty to go to prison😎
These sort of blokes can make you doubt yourself and love to think they look big in the merchants. Rant over!!😡

 

[Bartdude]

I don't do an additional stabilisation period at 20mbar.The let-by test at 10mbar also acts as a stabilisation period.

It's not mandatory to do a tightness test on a service either.

 

[GQuigley67]

I hate guys like that who make you doubt your own best judgement, just because they are so full of themselfs and manipulative, I was working in my mates house fixing his shower and his step dad was trying to give me advice then saying what i done was wrong, me scratching my head trying to figure out what for 10 mins then realised i was right ! wish he just kept out my way !

But a normal test is 1 minute let by, 1 minute stabilisation if it drops bellow 20mb put it back up to 20mb for 2 mins tightness, if there is a drop which is in tolerance of the meter during the tightness test then it should be fine unless there is a smell of gas. Although you only do a tightness test if you are working on any gas pipework, I don't think one is needed for a boiler service I would do a mini tightness test if I was working on a boiler sometimes where you isolate the gas supply to the boiler and check for tightness from P1

 

[leelister6]

It's not mandatory unless you touch the gas. I do one for my own peace of mind and have actually found a couple of leaks that the customers didn't know about elsewhere in the property. I you do a service and a customer reports a smell of gas afterwards, the finger will automatically point at you, then you've got all the hassle that comes with that, all for the sake of 4 minutes. Do it by the book and no-one can argue!

 

[nysk2008]

did you give there horses out the front any water, its pretty warm today, actually I think I can hear their stirrups clinking in the distance, hope their not working round here.

Just checked my viper and Medium Pressure Installations are max 2bar and min 75mbar

 

[royston]

Tell the morons to come on here later for some discussions ! Agreed with above times and tests. I always do my tests before i touch any gas appliances or pipework.

 

[REDSAW]

Sound like the sort of tossers I used to see in Plumb Centers all the time before I stopped using em; Snickers work trousers (Regulation bright blue), Walk straight round counter like they own the place and get their gear from the back themselves, rest beer gut on counter while drinking free coffee and telling everyone that will listen that "They're pulled out with work, aint had a day off since 1976, fitted 2 full systems since 8 this morning and still got another 3 to fit before 4 o clock & I don't need to do a tightness test cos I'm the bestest fastest gas fitter in (Insert the town/city of your choice)!" I always do a test before and after every job cos to be honest, I'm just too pretty to go to prison😎
These sort of blokes can make you doubt yourself and love to think they look big in the merchants. Rant over!!😡

you know the guy that trained me then, this is a copy to how i would describe him.
taught me to do a let-by at 6mb, went into the center with this and i didnt know which way to turn.git.

 

[mfgs]

You dont have to do a tightness test if you are just servicing the boiler and you can isolate the gas at the appliance.

 

[fuzzy]

do you think its wise to do one though?

 

[Bartdude]

Well,at the risk of playing Devils' Advocate technically these guys were right.

The actual test period is 2 minutes,and you don't have to do a tightness test if you're doing routine maintenance on an appliance. So going by the information in the original post it seems to be factually correct.Whether it's bad practice or not is another matter however.

 

[tamz]

A tightness test should always be done before you start working.


Anyone who doesn't is not only stupid but also incompetent.

Low pressure is up to 75mb, medium pressure 75mb - 2 bar.
This pressure relates to the incoming service and the outlet pressure (domestic) will be the same regardless (some i&c stuff will be higher) and slightly different test methods are used but the same principles apply.

Even if you don't do a tightness test on a service if you are isolating it at the valve, any broken joints still need testing with soapy.

 

[leelister6]

I think i'll continue to do a test before and after every job, when all's said and done it takes minutes.

 

[mfgs]

do you think its wise to do one though?

If a customer complains of a smell of gas or asks me to test it, I will. For just a service on an appliance with an isolation valve there is no need to, thats the way I have been shown and taught. As tamz said, any disturbed joints I always soap up or if hard to get to with LDF use my gas sniffer.

 

[AWheating]

if your going to meter to do gas rate or working pressures then i cant see any reason not to perform a tightness test on any type of work, if you find a problem then you may gain extra work too. 😉

 

[kirkgas]

you must perform a tightness before touching any part of the gas installation to make sure you have not caused a leak yourself. for example you test and find a 2mb drop, then carry out your work, test again and you have a 3mb drop. Something you have done may have caused the extra drop and will need checking.

If you dont perform the first test then you cant be sure of your own work being correct, and also if you dont test first and it has a drop outside the allowable limits then you will be responsible for finding the problem im my eyes.

It takes 3-4 mins to do a correct tightness test, i cant see what you will save by not doing one?

can you clarify what you mean by the bit i have highlighted, if taken literally as ANY work needs a TT then you are wrong, you do not NEED to do a TT when you service or repair a gas appliance for a private customer (by that i mean not a tenanted property) if you mean before altering or adding to a carcass then i agree with you