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Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

Apr 9, 2019
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Heating Engineer (Expired GSR)
I’m curious why gas is regulated to such low pressures when it enters a dwelling.

My gut instinct says this is for safety but then there is an argument smaller pipes could be made from stronger materials, have smaller leak paths and are less likely to be damaged.

Given this seems to cause issues I assume there is a sound reason for this, or is this a legacy from the days of town gas?
 
I’m curious why gas is regulated to such low pressures when it enters a dwelling.

My gut instinct says this is for safety but then there is an argument smaller pipes could be made from stronger materials, have smaller leak paths and are less likely to be damaged.

Given this seems to cause issues I assume there is a sound reason for this, or is this a legacy from the days of town gas?

The pressure in the network varies. It is brought down to the pressure we require to operate appliances to the manufacturers performance requirements. In other words, it's enough.

It is better to have gas pressure as low as possible for safety reasons e.g. if it leaks at a higher pressure, more will escape. If that occurs near or within residential areas, there is a high risk of damage, injury or even death from fire or explosion.

Underground pipework is old (a lot of it is) and leaks anyway, so if the pressure is higher than required, there will be more repairs to carry out, more complaints and most importantly, more risk of explosion. Those are few of my thoughts! I hope they help?

Towns Gas pressure was lower than the current pressure at the point of entry to a dwelling, (roughly half or there and there about).
 
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The network seems to run at the sort of pressured you’d kind of expect. It’s when it actually reaches a property and is regulated down to 30mbar it seems a bit odd.

I guess if you put a screw through a pipe it will leak at a lower rate.
 
The network seems to run at the sort of pressured you’d kind of expect. It’s when it actually reaches a property and is regulated down to 30mbar it seems a bit odd.

I guess if you put a screw through a pipe it will leak at a lower rate.

Hmm. Maybe you should stick to the North Sea?

I don't actually know what the pressure is in London mains, but I do know that there is not enough pressure in the network to provide a universally satisfactory 24hr supply to dwellings in dense urban areas.
 
Hmm. Maybe you should stick to the North Sea?

I don't actually know what the pressure is in London mains, but I do know that there is not enough pressure in the network to provide a universally satisfactory 24hr supply to dwellings in dense urban areas.

A helpful and informative comment, much appreciated.
 
The low pressure network can run at a theoretical max pressure of 75mb. Having said that, the highest ive seen is about 50mb standing pressure which many people would be glad of. Typically the standing pressure would be 23-30. As more and more older cast iron mains are replaced with plastic,it will be possible to admit higher pressures to those sections.
 
You are talking about medium pressure gas main. Regulator for domestic is set to 20 to 23mbar working pressure. Standing pressure 25mbar. anything outside this perimeter requires attention. Please don't confuse this forum with what you think is clever. The forum is a mainly domestic and light commercial.
 
The pressure in the network varies. It is brought down to the pressure we require to operate appliances to the manufacturers performance requirements. In other words, it's enough.

It is better to have gas pressure as low as possible for safety reasons e.g. if it leaks at a higher pressure, more will escape. If that occurs near or within residential areas, there is a high risk of damage, injury or even death from fire or explosion.

Underground pipework is old (a lot of it is) and leaks anyway, so if the pressure is higher than required, there will be more repairs to carry out, more complaints and most importantly, more risk of explosion. Those are few of my thoughts! I hope they help?

Towns Gas pressure was lower than the current pressure at the point of entry to a dwelling, (roughly half or there and there about).
thats why after midnight the grid pressure is lowered to lower the gas leak rate
 
thats why after midnight the grid pressure is lowered to lower the gas leak rate

I’m quite sceptical about that, gas distribution still utilises quite a lot of positive displacement and turbine flow meters, if you change if you changed the pressure by any significant amount these would give massive errors unless you do a lot of maths.
 
You are talking about medium pressure gas main. Regulator for domestic is set to 20 to 23mbar working pressure. Standing pressure 25mbar. anything outside this perimeter requires attention. Please don't confuse this forum with what you think is clever. The forum is a mainly domestic and light commercial.

It wasn’t meant to be clever I was just curious why such a lot pressure is used domestically. Kind of seems like it causes problems like having to run 28mm gas pipes to boilers.
 
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I’m quite sceptical about that, gas distribution still utilises quite a lot of positive displacement and turbine flow meters, if you change if you changed the pressure by any significant amount these would give massive errors unless you do a lot of maths.
I’m quite sceptical about that, gas distribution still utilises quite a lot of positive displacement and turbine flow meters, if you change if you changed the pressure by any significant amount these would give massive errors unless you do a lot of maths.
 
Thought of this thread when I saw this 😀

DA61B11D-DB0A-480D-96A1-09237205C4C7.png
 
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