15mm or 22m for correct gas pressure

[fixitflav]

Not necessarily

If supply pressure (to meet regs) is 21+/-2mbar at meter outlet, and maximum allowed pipe loss is 1mbar, I make that minimum pressure at meter outlet 19mbar, and 18mbar at the boiler.
But I just googled it make sure the 21+/-2mbar is at meter outlet (as I'd expect), and and there is a wide range of opinions, some saying the pressure required in practice at most boilers is much lower than 18mbar. Ask 10 GSR guys and you get 11 opinions!

 

[fixitflav]

I'm asking you.

And define boiler inlet.

The boiler inlet pressure tapping point, upstream of the gas valve.

 

[Dan Robinson]

Yep. I'd stop commenting on gas issues.if I were you.

 

[OvertonPlumber]

There

We had Glowworm request we repipe a boiler once. Was literally next to gasmeter..say 1.5mtrs of 15mm pipe. Still insisted we repipe in 22mm which we did at no cost.

Had to repipe a 40kw ideal once someone had replaced a Wau just connected of the 15mm pipe. Funny the hot water wasnt very good.

 

[FiremanT]

If supply pressure (to meet regs) is 21+/-2mbar at meter outlet, and maximum allowed pipe loss is 1mbar, I make that minimum pressure at meter outlet 19mbar, and 18mbar at the boiler.
But I just googled it make sure the 21+/-2mbar is at meter outlet (as I'd expect), and and there is a wide range of opinions, some saying the pressure required in practice at most boilers is much lower than 18mbar. Ask 10 GSR guys and you get 11 opinions!

That is because ypu do not know the rules.

What you have to work to and what someone else has done are completely different things.

To explain the rules is too complicated to bother with, and probably above your head

 

[Dan Robinson]

I'm baffled by the need people seem to have to post twaddle on things they don't know about.

 

[fixitflav]

Yep.

Does that mean you agree? If so, what's the problem? As usual, you're making generalised insults but not saying how you disagree with anything I've said.

 

[Dan Robinson]

No, I don't agree. I'm saying you're clueless. It's not an insult. Its a statement of fact.

 

[fixitflav]

What you have to work to and what someone else has done are completely different things.

Where have I said anything about working to what someone else has done? I'm saying look at it as it is and work out what pipe size is needed.

and probably above your head

As you have no more idea about my ability to understand things than I have about yours, that's too silly for any further comment.

 

[fixitflav]

No, I don't agree. I'm saying you're clueless. It's not an insult. Its a statement of fact.

Here we go again, more of the same. If the tapping point is not at the boiler inlet, where is it?

 

[Dan Robinson]

Here we go again

No point whining about things. Just stop posting on things you are not qualified or informed on.

P1 could be at the end of a 4mbar internal drop FFS.

 

[fixitflav]

P1 could be at the end of a 4mbar internal drop

OK, so if you measure pressure there, and it's 4mbar plus some pipe loss lower than the meter, do you conclude there's a problem, as it's > 1mbar? If not, how do you confirm pipe loss is < 1mbar? Fit another tapping point upstream of the internal drop, on the pipework? I bet that happens a lot! Boilers I've seen have just 2 tapping points, inlet pressure and burner pressure.

 

[Grumpy Gasman]

OK, so if you measure pressure there, and it's 4mbar plus some pipe loss lower than the meter, do you conclude there's a problem, as it's > 1mbar? If not, how do you confirm pipe loss is < 1mbar? Fit another tapping point upstream of the internal drop, on the pipework? I bet that happens a lot! Boilers I've seen have just 2 tapping points, inlet pressure and burner pressure.

The above question you ask suggests that you should refrain from commenting on any future gas related topics.

 

[ianmcd]

OK, so if you measure pressure there, and it's 4mbar plus some pipe loss lower than the meter, do you conclude there's a problem, as it's > 1mbar? If not, how do you confirm pipe loss is < 1mbar? Fit another tapping point upstream of the internal drop, on the pipework? I bet that happens a lot! Boilers I've seen have just 2 tapping points, inlet pressure and burner pressure.

OH Dear !!!

 

[snb]

Here we go again, more of the same. If the tapping point is not at the boiler inlet, where is it?

Afraid fixitflav you are well out of your depths here. And the giving out of gas advise outside of the combustion chamber is not allowed under the forum rules. you can do as much fishing as you like on google but i'm afraid certain information is restricted and is not available on the internet unless you have certain passwords/ memberships for various sites to gain access. This is done so illegal gas work is not encouraged, and untrained/unqualified can't find the answers.