Gas related question - is that still ok ?

[Old Account]

Hi guys,

As everybody knows I am currently doing my acs course and I had my 4th lesson done. We are currently calculating pipesizing.

However, currently I have got a job were we install a new central heating system and a complete new gas pipe from scratch.

I was yesterday calculating if we installed the right pipe size. I came to the conclusion that when you've got more than 1mbar drop you will need to upgrade the pipe to the next bigger pipe size.

I calculated over a 1mbar drop with the installation we have got. So basically my tutor meant we should upgrade to the very next size which would be 28mm.

Could anyone give me an idea if I am correct or not?

13,5m of 22mm pipe
5 pulled bends, 3 x 22mm elbows

My mate said, it is fine we don't need to upgrade the pipework... I believe him as he's experienced and I am sure it will work but usually you should upgrade according to my logic gas book.

Kind regrads
Ron

 

[mfgs]

If you are doing your ACS you should have all the relevant books and paperwork to allow you to calculate it. Also your mate who is signing it off, is ultimately who needs to be happy with it as he is the one doing the paperwork and signing it off. You seem to question him quite a lot on here.

 

[Old Account]

If you are doing your ACS you should have all the relevant books and paperwork to allow you to calculate it. Also your mate who is signing it off, is ultimately who needs to be happy with it as he is the one doing the paperwork and signing it off. You seem to question him quite a lot on here.

I am undertaking right now my Theorie and based on what I learned I was wondering what you guys would do.

I am not questioning his knowledge as I know he has got the knowledge. It is a good practise for me train on site for the future, therefore I was calculating the pipe size and found out that pipe should be upgraded to 28mm. I am pretty sure it will work with 22mm but as mentioned regarding to my book and regs it should be upgraded.

Wouldn't you wonder a little that he did not calculate at all the new gas pipe? He just said it's 22mm it will be enough. I am also a little curious as he never does a gas tightness test when he installed new boilers nor services ? So I think ive got a reason to question a little.

 

[ShaunCorbs]

You've missed one bit of info load on the gas pipe just boiler or boiler cooker fire etc and kw rating or m3/h

And if let's say it's 18 mbar at the meter and 16 mbar at a test nipple under the boiler (gas valves add more restiveness normally listed in mi)

It would need a bigger pipe installed (if this is a new install) if it's just a service / check different ball game

 

[Scott_D]

What appliances?
Have you tested the pressure drop or just working it out on paper?

 

[mfgs]

I am undertaking right now my Theorie and based on what I learned I was wondering what you guys would do.

I am not questioning his knowledge as I know he has got the knowledge. It is a good practise for me train on site for the future, therefore I was calculating the pipe size and found out that pipe should be upgraded to 28mm. I am pretty sure it will work with 22mm but as mentioned regarding to my book and regs it should be upgraded.

Wouldn't you wonder a little that he did not calculate at all the new gas pipe? He just said it's 22mm it will be enough. I am also a little curious as he never does a gas tightness test when he installed new boilers nor services ? So I think ive got a reason to question a little.

You clearly have concerns over his work and knowledge, maybe its better to find someone else until you are qualified rather than constantly trying to check up on him.

 

[Scott_D]

Never does a tightness test?

 

[Old Account]

What appliances?
Have you tested the pressure drop or just working it out on paper?

I just worked it out on paper without including the gas hob.

I just calculated pipe length 13,5m and the boiler with 27kw.

@ShaunCorbs i just have a boiler with 27kw, and a gas hob and the gas supply is brand new from scratch.

• Front left: High-speed burner - 3 KW
• Rear left: Standard burner - 1.7 KW
• Rear right: Standard burner - 1.7 KW
• Front right: Economy burner - 1 KW

I didn't even include the gas hob and if I include that I will have even a bigger drop of mbar.

@mfgs i am just cautious as I am clearly running a business which means i cannot allow myself to have complaints from my customers. However it's not relevant right now If i am having an issue or not the question i was asking if the pipework should be upgraded or not.
I appreciate your help and advise and respect what you are saying.

 

[Old Account]

Never does a tightness test?

We have done 2 boilers recently and he hasn't done 1 tightness test to see if there any gas leak.

 

[ShaunCorbs]

wtf you need to do a tt as if the system is leaking its down to you

are you 10000% sure he never did a tt

 

[Old Account]

wtf you need to do a tt as if the system is leaking its down to you

are you 10000% sure he never did a tt

10001%

 

[ShaunCorbs]

I just worked it out on paper without including the gas hob.

I just calculated pipe length 13,5m and the boiler with 27kw.

@ShaunCorbs i just have a boiler with 27kw, and a gas hob and the gas supply is brand new from scratch.

• Front left: High-speed burner - 3 KW
• Rear left: Standard burner - 1.7 KW
• Rear right: Standard burner - 1.7 KW
• Front right: Economy burner - 1 KW

I didn't even include the gas hob and if I include that I will have even a bigger drop of mbar.

@mfgs i am just cautious as I am clearly running a business which means i cannot allow myself to have complaints from my customers. However it's not relevant right now If i am having an issue or not the question i was asking if the pipework should be upgraded or not.
I appreciate your help and advise and respect what you are saying.

but its off the same line as the boiler true or false?

 

[ShaunCorbs]

10001%

naughty naughty

 

[Old Account]

wtf you need to do a tt as if the system is leaking its down to you

are you 10000% sure he never did a tt

I know it's wrong that's why I am wondering about the 22mm pipe size if that's enough or if that has to be upgraded

 

[ShaunCorbs]

I know it's wrong that's why I am wondering about the 22mm pipe size if that's enough or if that has to be upgraded

give us the full facts then cant work it out half arsed

do a drawing of the gas line elbows ts appliance etc

distances from meter to to the cooker t cooker t to boiler you get the drift

will work it out for you but need everything

 

[Old Account]

naughty naughty

The only thing he does is gas rate, and flue gas checks. When he Services he doesn't hieven take the boiler cover off. We recently serviced a conventional boiler potterton and he just checked 2 x gas fires with smoke test, flue gas analysed, and that was it. So I think I have got a reason to be concerned

 

[Old Account]

give us the full facts then cant work it out half arsed

do a drawing of the gas line elbows ts appliance etc

distances from meter to to the cooker t cooker t to boiler you get the drift

will work it out for you but need everything

Ok give me a minute please.

 

[ShaunCorbs]

The only thing he does is gas rate, and flue gas checks. When he Services he doesn't hieven take the boiler cover off. We recently serviced a conventional boiler potterton and he just checked 2 x gas fires with smoke test, flue gas analysed, and that was it. So I think I have got a reason to be concerned

yes and no stnd bg service

do you know the fga reading off the boiler?

 

[Old Account]

yes and no stnd bg service

do you know the fga reading off the boiler?

What does fga mean ?

 

[ShaunCorbs]

What does fga mean ?

flue gas analyser, did he do one?

 

[Old Account]

give us the full facts then cant work it out half arsed

do a drawing of the gas line elbows ts appliance etc

distances from meter to to the cooker t cooker t to boiler you get the drift

will work it out for you but need everything

 

[ShaunCorbs]

View attachment 29972

now your learning give us 5 mins

 

[Old Account]

flue gas analyser, did he do one?

Unfortunately I do not know the readings but if I asked my customer I could get a picture of the gas certificate.

 

[ShaunCorbs]

right since cooker and boiler are so close dont need to worrie about cooker just add it in with boiler

boiler 27kw + cooker 8 kw = 35 kw

aprrox 0.3m for a pulled bend and 0.5m for an elbow

so 6 pulled bends and 4 eblows

13.5m + 1.8 (pulled bends) 2m (elbows) so total = 17.3m

so you need 35 kw at 17.3m from the meter

its on the max drop of 22mm so i would recommend 28mm giving a drop of 0.40 mabr

(to work it out into m3/h)

kw / 10.65 = m3/h (35/10.65 = 3.28 so 3.30m3/h

so look at your table of m3/h that copper can carry and you will see 22mm will just but its maxing it out

 

[ShaunCorbs]

View attachment 29972

hows the copper going from the meter to the appliance in the floor? if so wooden ? etc