pressure drops

[desrob]

measuring the pressure at the meter with the boiler running at full rate, i recorded a pressure of 22m/bar and at the inlet on boiler gas valve i recorded a pressure of 20 m/bar, would you class this as a 2m/bar drop ?

 

[tamz]

Not bad at all

 

[desrob]

yes but according to my recorded pressure measurements i have a 2 m/bar drop across the installation, so therefore it's not acceptable, or is the measurements at the meter subjected to a + or - 2m/bar

 

[tamz]

There is a greater pressure loss through the gas valve. If you want an accurate reading you will need to fit a test nipple to the pipe as it connects to the boiler.
Here is a clear explanation from worcester

 

[gbgas001]

The test only gives an issue under the British Standards, What does the manufacturers instructions say. Most fan assisted appliances due to the fact that the appliance sucks gas through the pipeline could have a inlet pressure of 17 mb (check with MI). so there for manufacturers instructions overide British Standards and it would be ok.

gb-gas

 

[smillsey]

like tamz says a 2.5mbar drop at the test nipple on a gas valve is normally only 1mbar on the actual pipework
I for one do not get into fitting test nipples just to confirm something i already know!

its 1mbar