new gas supply

[Mike Jackson]

Sorry but the maximum 1mb pressure drop for domestic installation is based on the premis that the minimum supply pressure at the meter is 19mb this is to guarantee an absolute minimum of 18mb at appliances.

If you have a higher starting pressure from the meter eg 75mb (which is the top end of the Low pressure scale) in the service pipe then you can afford to lose 53mb over the 180 metres in this case .. and then install appliance regulators to control the appliance pressure as required.

Someone with a mears wheel might calculate the pressure drop over 180 metres of (say) 28mm pipe at 75mb

This is effectively what the gas supplier would be doing by fitting the meter and governer in the property but with the huge advantage that they have responsibility for repair or replacement of the pipework up to and including the meter. As a domestic gas safe registered installer I can work on natural gas at 21 +/- 2 mbar and LPG up to around 40 mbar. Working at higher pressures will require someone with a commercial ticket and maintenance costs will be vastly higher. The only sensible way of dealing with this is to have the meter in the property or look at alternative energy sources.

 

[wheeto]

Working at higher pressures will require someone with a commercial ticket and maintenance costs will be vastly higher

Or larger system volumes / large pipe sizes, as posted on previous page.

The only sensible way of dealing with this is to have the meter in the property or look at alternative energy sources.

Spot on.

 

[Joncpi]

I am sorry but, you are not correct. In ANY gas system, domestic or commercial, pipe sizing is everything. In this case you may possibly be able to get the gas supplier to give you slightly higher pressure at the meter, but only up to 23mbar. In a commercial system once the starting pressure is over 23mbar you are allowed, not "can afford", a pressure DROP of 10%. So a system that has a 53mbar pressure drop requires a start pressure of 530mbar (just over 0.5bar)

 

[wheeto]

I am sorry but, you are not correct

Who ?

 

[Joncpi]

Not you, wheeto. I agree a commercial gas engineer is more expensive, maybe not "vastly" though, and I agree it would be easier if the meter is at the house, but as I have said, not essential.

 

[TGor]

I am sorry but, you are not correct. In ANY gas system, domestic or commercial, pipe sizing is everything. In this case you may possibly be able to get the gas supplier to give you slightly higher pressure at the meter, but only up to 23mbar. In a commercial system once the starting pressure is over 23mbar you are allowed, not "can afford", a pressure DROP of 10%. So a system that has a 53mbar pressure drop requires a start pressure of 530mbar (just over 0.5bar)

Aware that this is a Hypothetical .. but the gas pipe sizing tables I have used, particularly in the US, allow pressure drops of well over 50% on medium and high pressure natural gas lines .. obviously your experience is different.. Not sure why design should be restricted by imposing 10% in this country though is there a particular reason for this??

 

[pcp]

Firstly many thanks to all who have contributed to this topic. Progress has been slow to get a responce from SGN regarding alternatives to original quote. they will run pipework to a remote meter but only in 32mm, they state that any pipe work they install must terminate at a meter, I was hoping they would terminate 63mm pipe at an ecv then an independant could connect from this to 180m pipe run/ laid by ourselves to a meter at the house. As the original quote from SGN was to run from the main in 63mm pipe to metrer position in house I assume any pressure drop would have been calculated for, as an hourly load of 60k Wh being the based upon.
Awaiting quote from indepenant company for connection from remote meter, hoping they will resolve all issues regarding pressure, if not looks like oil is next best bet.
Again many thanks to all.

 

[Joncpi]

SGN do not have to abide by the 1.0mbar pressure drop or the 10% rule as they are "before the meter" different rules apply. Their supply pressure is likely to be between 75mbar and 2.0bar. Depends on the main pressure in the road. It could be lower, but they will still ensure there is sufficient gas for what ever size of meter you need and that this can supply the maximum load you need.

 

[grahamgas]

Have you got room for a bulk lpg storage tank?
If so then that is what I would look at first, then the ashp or gshp option.

Graham

 

[Joncpi]

Aware that this is a Hypothetical .. but the gas pipe sizing tables I have used, particularly in the US, allow pressure drops of well over 50% on medium and high pressure natural gas lines .. obviously your experience is different.. Not sure why design should be restricted by imposing 10% in this country though is there a particular reason for this??

IGE/UP2 codes, Testing and Purging, section 4.4.4 It actually says anything over 21mbar is allowed a 10% drop. However I always used 23mbar as a cut off point to allow for a margin of fluctuation in the gas supply pressure. Also I believe there is talk of a change to this ruling of 10%, but nothing definite yet as far as I know.