Gas Meter working pressure

[billy_smith]

Quick query here,

If testing working pressure at a gas meter should all gas appliances be running at full rate ?

IE Combi boiler with Hot tap running and gas hob with 4 rings burning.

I had a chat with the fitter today, he tested meter with boiler running full but didn't have the hob running for meter test, he then tested working pressure at boiler with the 4 rings on hob burning.

I would have thought this would give a false reading ?

I'm a retired plumber so have limited knowledge with gas works etc but I like to keep in the know !!

 

[45yearsagasman]

Your plumber knows what he's doing.

 

[billy_smith]

So only the boiler need to be running on max when checking pressure at meter.

Thanks

 

[Agile]

When testing the working pressure at the boiler, did he have the boiler ON or just the four gas rings?

The useful test is to put the boiler on full and test the working pressure at the meter and at the boiler.

The difference becomes the pressure loss in the pipework.

There can be some confusion here because traditionally the working pressure at the meter has been defined as with three gas rings working.

That has become rather irrelevant now that many boilers are 24 kW or more. So the minimum should be with the boiler working on max although there is a good argument that the system should be tested with all appliances on full to give the worst case.

Tony

 

[billy_smith]

When he tested working pressure at the boiler he had the boiler running on full and he also turned the 4 rings on the hob on.

When he tested working pressure at meter, he turned boiler on full but didn't turn the hob on at all.

 

[45yearsagasman]

That's perfectly acceptable. Like I said, your man knows what he's doing.

 

[Agile]

When he tested working pressure at the boiler he had the boiler running on full and he also turned the 4 rings on the hob on.

When he tested working pressure at meter, he turned boiler on full but didn't turn the hob on at all.

Thats a bit odd!

Most would make the measurement at the boiler and then at the meter with everything all working.

That provides the pressure loss in the pipework!

 

[Jackrae]

If the boiler was a new installation then during the second test he was most probably actually testing the consumption rate of the boiler. He does this by noting gas meter change for a given time period. Since he'd already done a boiler pressure test with all systems fired he could immediately determine if the meter governor was OK since any problems with the governor would have caused an unacceptable loss at the boiler.