Keeping a gas test on for 24 hours????

[Rich]

Hi,
I work for a company that have installed gas pipe in a new build. There is approximately 200 meters of 3" pipe. The company who are commissioning the pipe work have said it needs to be on test for 24 hours at a pressure of 150 mbar.

Does this sound right?? Seems like a very long time?

Thanks for the help,

Rich.

 

[macplumb]

There's a lot of pipe work so a small leak would take a long time to show. Where a 1m run of pipe with a small leak would drop fast

 

[Rodreguez]

sounds right to me as it came up on my commercial ACS's i think

 

[plumbster3456]

wow 24 hrs what if it drops you need to find a leak repair it then realise 24 hrs later theres another leak lol the 2 min one we all do now is starting to become dreaded the amount of times we got to do them

 

[Gray0689]

wow 24 hrs what if it drops you need to find a leak repair it then realise 24 hrs later theres another leak lol the 2 min one we all do now is starting to become dreaded the amount of times we got to do them

It's for commercial gas not domestic

 

[plumbster3456]

I know that i am making a joke.... obviously they would not make u do it on domestic for 24 hrs as 99 out of a 100 existing installs would be at zero after a few hours

 

[GQuigley67]

you'll know if there is a drop in a couple of hours anyway i'd imagine while your on site

i done pressure tests on water services in commercial, we left it pressurised with air overnight also

 

[plumbster3456]

I worked on commercial too years ago we also tested with air cant remember the time more than the usual hour but not overnight.
cant stand it doing commercial work

 

[GQuigley67]

sometimes we left it over night at 3 bar, usually if it was a monday night or somethin lol

 

[plumbster3456]

dodgy testing with air seen a 42 or 54mm gate valve blow off and smack the wall during a test if it hit someone it would have killed them,

 

[GQuigley67]

the building was not in use everyone would be away home as we'd be working late doing the test as you know sometimes they take ages to get up, and then we were always the first ones in as we started at 7.30

 

[plumbster3456]

the building was not in use everyone would be away home as we'd be working late doing the test as you know sometimes they take ages to get up, and then we were always the first ones in as we started at 7.30

think if i remember right some of the main contractors did start saying that if testing with air it had to be on a saturday when the building was empty maybe thats why now that its years past since i done commercial that they require it at night when building is empty

 

[GQuigley67]

yeah building must be empty, cant have a building site full of people more risk of someone getting injured as u know there is almost always something that blows off

 

[Reg Man]

IGE/UP/1. This don't sound right. 24hrs? will check it out.

 

[plumbster3456]

IGE/UP/1. This don't sound right. 24hrs? will check it out.

they go over the top all the time some of the house builders wanted water and heating pipes tested to 20 bar even though the water bylaws and bs 6700 both say 1 and a half times the maximum working pressure if this was not sufficient then why is it recommended to test to that

 

[GQuigley67]

20 bar ? talk about extreme lol

 

[Bartdude]

Was that the pipes only? Most valves are rated for 10 bar only.

 

[plumbster3456]

Was that the pipes only? Most valves are rated for 10 bar only.

when just pipes especially parts that would go under something that you couldnt get at later then later date rads fitted valves and sanitery ware etc.
people go over the top all the time seen a clerk of works literally hanging and pulling at a unit to see how strongly fixed it was what a jobsworth

 

[tamz]

IGE/UP/1. This don't sound right. 24hrs? will check it out.

Rounding volume up to 1.2 and combining strength and tightness using air and an electronic guage to 2 dp's (volume too big for a std wg)

5min + 5 min + 5 min (15-10) + 9 min = 24mins

 

[Reg Man]

Thanks for checking this out. Looks right now.

 

[plumbster3456]

Rounding volume up to 1.2 and combining strength and tightness using air and an electronic guage to 2 dp's (volume too big for a std wg)

5min + 5 min + 5 min (15-10) + 9 min = 24mins

do you have to test for 24 mins then on pipes this size? not clued up on commercial gas just domestic gas only done pipe fitting and plumbing commercial

 

[tamz]

do you have to test for 24 mins then on pipes this size? not clued up on commercial gas just domestic gas only done pipe fitting and plumbing commercial

You need to calculate it. Test times depend on volume, guage selection, test medium etc. New work also needs strength tested.
The above numbers were for a combined strength and tightness test of just a pipeline. Doing them separately would have added 10 minutes.
Bit hard to explain fully without rambling on for pages but formula is GRM x IV x F1 all dependent upon different things
GRM = gauge readable movement
IV = installation volume
F1 = multiplication factor
The MPLR (allowed drop) also needs calculated.

 

[plumbster3456]

You need to calculate it. Test times depend on volume, guage selection, test medium etc. New work also needs strength tested.
The above numbers were for a combined strength and tightness test of just a pipeline. Doing them separately would have added 10 minutes.
Bit hard to explain fully without rambling on for pages but formula is GRM x IV x F1 all dependent upon different things
GRM = gauge readable movement
IV = installation volume
F1 = multiplication factor
The MPLR (allowed drop) also needs calculated.

so you do a bit a commercial gas then tamz? or do you just know your stuff..... seems a bit daunting with all the calculations seems like there would be a lot more calculations than there is in domestic gas anyway...

 

[tamz]

I do some I&C gas among other stuff. The calculations are a pain to get your head around to begin with but it comes to you. A lot different to domestic.

 

[Reg Man]

so you do a bit a commercial gas then tamz? or do you just know your stuff..... seems a bit daunting with all the calculations seems like there would be a lot more calculations than there is in domestic gas anyway...

Tamz knows what his doing.