Pressure loss through the pipework

[markadams]

I have recently read a couple of posts on here that specify that the pressure loss from the meter to the applicate can be a max on 1.5 mbar.

I always understood it to be 1.0 mbar. Has it changed without my knowledge? I am due to resit my assessment soon so it was a while ago.

Mark.

 

[Scott_D]

1mb as far as I know
Then losses through boiler and gas valve as per MIs

 

[Darren Jackson]

Permissible drop of 1 mbar from meter to appliance is what I always believed and as far as I know it still is.

 

[ShaunCorbs]

From gas valve test port some 1.5 some 4.5 mbar

 

[Darren Jackson]

From gas valve test port some 1.5 some 4.5 mbar

Can you explain further Shaun? I too am re-taking my ACS in a couple of months & I always thought it was 1 mbar drop from governor to appliance.

 

[ShaunCorbs]

Can you explain further Shaun? I too am re-taking my ACS in a couple of months & I always thought it was 1 mbar drop from governor to appliance.

Depends where you take it from if there's a test point before the gas valve e.g. On the gas ISO valve then it is ,

But if your testing on the gas valve manufacturer instructions will tell you the drop Worcester are 1.5 and I think vaillint are 4.5

Understand?

 

[markadams]

Well it seems that it is not the case on the Ideal boilers, if taking a reading at the isolation valve test point then you can allow a higher loss based on the KW rating (as per the MI)

 

[quality]

if you take the reading from the isolation valve there should be max 1mb loss if from the gas valve some manufacturers allow a bigger loss

 

[ShaunCorbs]

Well it seems that it is not the case on the Ideal boilers, if taking a reading at the isolation valve test point then you can allow a higher loss based on the KW rating (as per the MI)

Why if it's straight through valve ? Be the same as cutting a test point below the boiler

 

[markadams]

The MI give an extra 1.75 mbar for a 30KW boiler.