quick question

[jackyp1234]

hard to describe but here goes,

my boss has just fitted a boiler room and now gone on holiday leaving me with a few little bits to do

1st there is an expansion vessel fitted but he hasn't run the pipe work for the pressure relief valve yet, so I am left with the 3 bar relief valve with a short pipe of half inch coming out of it, i need to work this round to the corner of the room where i have brought a 1' 1/2 waste pipe up, to take condensate, this blow off and another blow of from the unvented cylinder.....

it will b very hard to fit a tun dish off the pressure relief valve as the vessel is sat on the floor, so too low to get your 300mm before the first bend, is it essential to fit tun dish on here? also can this pipe connect into the blow off from my cylinder, which is in 3/4 with a Tun dish,

if you can imagine, my waste pipe comes up on an elbow, then goes vertically up about 3 inches, then has a tee, which is facing so the brach off the tee picks up the condensate and i wanted to fit a 22mm reducing tee above the top of the waste tee and drop my blow off into it

very hard to explain but with my boss being away im not sure where else to turn for advice!!

THANKS FOR READING!1

 

[GrahamM]

If you are asking these questions you are obviously not qualified to fit an unvented cylinder. I would not go any further.

 

[Gray0689]

Yes just connect pipe from prv to your discharge pipe from cylinder

 

[jackyp1234]

I knew some one would write that! Lol But could you please respond as to why you would say that?

 

[kay-jay]

I knew some one would write that! Lol But could you please respond as to why you would say that?

cos if you don't know what you are doing you could blow up the building!

 

[Gray0689]

Read op the cylinder is already in he is only connecting the discharge ps your boss must of had a little bit of faith in you to leave you on your own but you need to open your mouth and ask him/her what they wanted doing before they went and if you had to write down what they wanted doing

 

[jackyp1234]

THANK YOU GRAY, SORTED IT ANYWAY.......you shouldn't be fitting this LOL im still learning

 

[AWheating]

yes you must fit the tundish and increase the size of the discharge pipe as per G3 regs and have your 300mm, if going to plastic pipework then it must be able to withstand high temps (ie pushfit) and it must have a hepvo valve fitted and written building control permission.

If you are unsure about any of it then google building regs part G section 3 (G3) and download and have a read, then you will know what to do next time.

if it does explode then its your gaffa's fault as much as yours, you can share a cell.... LOL (joke)

 

[jackyp1234]

Thanks for advice, going to sound stupid now but i know about tundish's off cylinders i just couldnt recall seeing one fitted off the expansion vessel. but thank you pal.....

 

[jackyp1234]

cos if you don't know what you are doing you could blow up the building!


not sure how it would cause the building to explode, if you read the post its discharges into a waste pipe (in the correct size copper) , which is dis charged into a gully......so either was if it was discharging how would it cause a problem? the only problem i can see is the air gap wouldnt be provided by then tun dish?

 

[AWheating]

if you are doing loads of these types of installs i would push your gaffa to let you take the unvented course, its a good qualification to have under your belt for future job prospects.

 

[AWheating]

cos if you don't know what you are doing you could blow up the building!


not sure how it would cause the building to explode, if you read the post its discharges into a waste pipe (in the correct size copper) , which is dis charged into a gully......so either was if it was discharging how would it cause a problem? the only problem i can see is the air gap wouldnt be provided by then tun dish?

how do you calculate the correct size discharge pipe?

also discharges can not be run in waste pipe unless connecting internally into waste system via a hepvo valve in hi temp waste pipe.

do the course, its worth it.

 

[AWheating]

without the air gap/tudish if the pipework got blocked or frozen and the cylinder overheated and could not discharge then the pressure will build untill the cylinder splits open at which point the hot water inside could turn to steam increasing in volume causing an explosion.

with the tundish the prv can still run/overflow.

if you go on youtube and search unvented cylinder explosions you can see what can happen.

 

[jackyp1234]

never knew you could run t and p ino waste pipe to be fair! will rip out tommorrow