Connecting on to existing gas run.

[Billy Bob Bob]

15mm to the inlet?????????????????they should lose their licence COWBOYS

 

[plumbster3456]

I have been to fix a few boilers over the years that bri***** gas have installed namely worcester with a 22mm gas valve on the outlet to boiler they had run the 22mm pipe out of valve and round out of site and connected it to the old 15mm pipe that was going to the old boiler.
Is bri***** gas not supposed to do things right ? or are the just the same as all these other cowboys who think this is ok to do

 

[kirkgas]

I have been to fix a few boilers over the years that bri***** gas have installed namely worcester with a 22mm gas valve on the outlet to boiler they had run the 22mm pipe out of valve and round out of site and connected it to the old 15mm pipe that was going to the old boiler.
Is bri***** gas not supposed to do things right ? or are the just the same as all these other cowboys who think this is ok to do

any registered gas company is just the same as the rest, doesnt matter how big or small they are, they are all guided by the same regs and MI's so every engineer should do the job properly,

 

[dazpara]

Expected to get shot with this one here, i agree totally with everything you guys are saying, tamz i wasnt comparing gas to water mate just stating that if you reduce down then back up a pipe size you'll only get the flow of the lower diameter pipe. I asked this question because i know its wrong what these guys are doing, and i can guarentee you that its not the standard i work to, however i have just past acs withing the last month and am awaiting my GSR number, now, i've been at this company for about 3 years and the guys that are doing these AR installs have been here a lot longer and have had their gas quals 18 months plus. If you were genuinly in my position of being basically a novice then what would you do or say to these guys. Put yourself in my place when considering this and not in yours, cheers.

 

[tamz]

Quick explanation.
Gas is different to water in that gas is compressible and water isn't.
Once the water flows through a smaller pipe then back to a bigger one, all you can get is the smaller volume.
With gas as it passes through the smaller pipe it compresses and expands again once in the bigger size.
Try it some time if you have a bit spare time. Cut a bit half inch into a 3/4" run and check the difference in flow/pressure. Not much.

With the 12.5mb thing.
The inlet pressure can be as low as 19mb, there could be a 4mb drop across the meter at high flow rates, a 1mb drop on the pipework and 1.5mb through the boiler inlet to the test point on the valve. Now the problem then becomes compounded if there is say a 2mb pipework drop then we are down to 11.5 and so on.
Btw the transporter only legally has to supply 14mb!! Do the sums on that one!

So far as what do you do.
Well as there is more than a 1mb drop obviously they are not doing it to standards. So pull them on it. They are doing it wrong. Don't worry about them being older or "more experienced" than you. A lot of experienced guys fk things up and think they know better.
Educate them

 

[wnjswozo]

1 m/bar drop on on pipework.gas rate the applaince,round off with fga,easy

 

[Blackcatgas]

you can lose 1.5 mb across the inlet of the boiler, Worcester Bosch had a technical artical out about it a few years ago basicly saying that the restriction through the isolating valve and pipe work to the gas valve was 1.5mb.

 

[Reg Man]

You hit the nail on the head, first discription. No way is this allowable. Another lazy installation. 22mm alll the way as long as its not to long a run. Have you tried to drink a McDonalds thick milkshake through a thin party straw? So how is the boiler going to operate within the requirements?

 

[smillsey]

why dont you just open up the esg on pipework discrimination, is it not in there?

 

[Billy Bob Bob]

pipework discrimination,?????????? never heard that one "is it because i is copper?" LOL