Gas question

[Huckerz]

I am currently a plumber in the process of becoming gas safe an have a questions.

Why can't you test the working pressure on new boilers?

Thanks for your time an help

 

[stevetheplumber]

if you mean burner pressure its because the are zero govenors the gas is actually sucked out by the fan you can do inlet pressure and working pressure at the meter

 

[albatross]

You can test the inlet working pressure.

You can't test the burner (working) pressure as it has a fan and a zero governor gas valve. The fan effectively sucks the gas through and you should read around zero on a gauge because of this.

On older boilers there is no fan or it only pushes the fumes out so a reading of gas pressure can be taken at the burner as the gas still has some pressure from the gas main.

You are welcome.

 

[albatross]

if you mean burner pressure its because the are zero govenors the gas is actually sucked out by the fan you can do inlet pressure and working pressure at the meter

You blooming type faster than me!

 

[Whyme]

you can take a working pressure usually before the gas valve or at the inlet, burner pressure is if the appliance has got an injector. Working pressure just means close or at the appliance as a rule of thumb. a more accurate reading would be gas rating the meter if no test point is available.

 

[albatross]

Working pressure just means close or at the appliance as a rule of thumb.

Working (or dynamic) pressure means an appliance is being used during the test as opposed to standing pressure when nothing is being used. Working pressure can be take anywhere depending on what you are trying to find out. At the appliance or the meter.

 

[Whyme]

i agree "working" ie (what the op said couldnt be done) can be done anywhere but more accurately for an appliance at an appliance then if you like at the meter to show the drop blah blah. all i was saying was "yes you can take a working pressure".

 

[paulsanderson]

worcester ask for a pressure differential in the book

 

[Ermintrude]

Ideal logic show on a graph dynamic losses on valves as each size appliance has different losses.