At working pressure why are you only allowed a 1mb gas pressure drop from the meter to appliance. For example if the appliance's MI states it can work at 17mb why are you still only allowed a 1mb drop? I have searched the internet for the answer to this and cannot find the actual technical term so answers appreciated.
1mb Allowance gas pressure drop from meter to appliance
- Thread starter stephenleespooner
- Start date
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Not all gas appliance have a governor, gas fires and hobs for example and are designed to work at 20mb working pressure, the meter should be set to give 21mb wp and with 1mb loss across the pipework give 20mb wp at the appliance.
The manufacturers are also taking into account the pressure loss across the appliance's internal gas train and the gas valve.
What is likely to happen if there is an inadequate pressure at appliance? This is merely curiosity and knowledge for myself & not related to a job by the way before anyone asks me to post in the Gas section
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if it is a fully modulating boiler then very little problems only you may not get the full input rate if underpressurised and may have problems igniting on some appliances but can cause real problems on fixed rate appliances and can make them ID if the pressure loss is excessive
And also what is the official Gas safe description of why you are only allowed 1mb per appliance? Last question I promise 
What kind of problems?
if its a fixed rate appliance you could possibly have incomplete combustion as the burner/injectors may have not been tested at lower pressures, I have seen under pressure appliances lighting back to the injector, can be very dangerous
Right you should be definitely be posting this in the CC.
Last answer...
Lack of pressure can mean fixed rate appliances are snuffed out when a larger demand is placed on the gas pie work. Leaving you with a dangerous situation where gas can escape when the larger demand ceases.
Alternatively, a boiler not supposed to condense could start doing so due to lower output.
However, if you are not an RGI, then the mechanics of such things are largely irrelevant. If you are doing private gas work, asking on here for technical advise is not all of a sudden going to make you competent.
If you are an RGI:
A - you should already know all this.
B - Post in the CC.
Last answer...
Lack of pressure can mean fixed rate appliances are snuffed out when a larger demand is placed on the gas pie work. Leaving you with a dangerous situation where gas can escape when the larger demand ceases.
Alternatively, a boiler not supposed to condense could start doing so due to lower output.
However, if you are not an RGI, then the mechanics of such things are largely irrelevant. If you are doing private gas work, asking on here for technical advise is not all of a sudden going to make you competent.
If you are an RGI:
A - you should already know all this.
B - Post in the CC.
Thankyou, helpful. Only interested in something, trying to learn, doesn't mean I'm doing anything dodgy Dan, you can't find this information on a normal google search, all sorts of things come up.
Good.
There is a reason we undergo the training and assessments we have.
Google warriors are a menace to society.
Cheers .
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