I HAVE HAD A NEW BOILER FITTED BY BRITISH GAS WITH A 22MM SUPPLY PIPE RUNNING ON THE OUTSIDE OF THE WALL STEPPING DOWN TO 15MM JUST BEFORE THE BOILER.
I AM NOW HAVING A KITCHEN FITTED AND THE PLUMBER RECKONS ITS ALRIGHT TO TEE OFF OF THE BOILER SUPPLY PIPE IN 15MM TO SUPPLY THE HOB IS THIS CORRECT? THE OLD CAST IRON SUPPLY PIPE TO THE OLD HOB COMES UP IN THE MIDDLE OF THE COOKER CABINET SO WE NEED TO MOVE IT OR LOSE IT !
To size a gas pipe correctly you need to know the heat input of all appliances running off that pipe. You also need to know the length of pipe run. To that length you need to add 1 metre for elbows and 1/2 a metre for pulled bends. These figures are required to ensure that there is sufficient gas available at all appliances so you cant just say 'that will be fine' and quote some big numbers me old fruit.
It makes no difference how long you've been in the trade when sizing gas pipes. You will need to know the heat input of the appliances and the length of pipe. Without theses details you introduce an element of risk. Dont take risks with gas. Corgi state that gas pipes must be sized according to the pipe length and the heat input of the appliances, but do not offer to waive this requirement if you've been in the trade for forty years. Why would anyone not do the calculations and introduce an element of risk????
Gentlemen, calm down please! We are only doing this out of a willingness to help others.
Can I add oil to these trobled waters and throw my spanner in?
You are both right in one way or another
1. He is not your old fruit!
2. Pipe length, numbers of fittings etc. must be taken into account, as well as heat input rating of all other appliances served by the gas meter.
Enjoy your day!
When the chap who does the decorating at my house turns up, he has a quick glance around the room, and then says, right, that's 30 litres of emulsion plus ten for the ceiling and gets cracking.........
Why.........because he's done it for donkeys years, knows what he's talking about and can calculate what is needed instantly because of his experience. He does not have to measure.
I have practiced my trade for forty years.......long before the CORGI was invented.
So now we have the know it all's........who in all likelyhood have no more experiance than a few weeks training course in how to instal a combi boiler.
(much beloved of amateurs .......because because it's so simple to fit that I could train a chimpanzee to install one in a day)
Perhaps one of you could explain to me how a 212 cubic feet per hour meter (normal domestic size) flowing through a 22mm pipe could not handle a domestic boiler and a hob ?
I don't understand the comparison between a chap estimating the amount of paint required to do a job, and the amount of gas available from a pipe.
I have been working with gas and oil fired boilers for as long as you, on a range of appliances from domestic cookers to 75,000,000 btu. HTHW and steam boilers.
That having been said, over the years I have worked with a few chaps young enough to be my son, but who I learned from.
You ask how a domestic meter could fail to deliver the gas required for a
boiler and hob.
From your training, you should know Sir. What if the appliance was in the West Wing of Buckingham Palace and the gas meter was in the East Wing 100 yards away? Do you think you would get it to fire on rate on a 22mm pipe?