On Fri, 15 Mar 2019 08:39:31 -0000, Chris J Dixon wrote:

Commander Kinsey wrote:

On Thu, 14 Mar 2019 22:10:54 -0000, Tim+ wrote:

Commander Kinsey wrote:
On Thu, 14 Mar 2019 20:26:21 -0000, Andrew Gabriel wrote:

The high pressure network represents a significant proportion of the
country's stored gas.

But is it usable?

Our reserves are now stored in the pipeline.

So presumably this pipeline is variable pressure?

https://www.nationalgridgas.com/balancing/nts-linepack

" Methodology

We determine NTS linepack by calculating the volume of gas within
the NTS pipelines, using a network model and instantaneous
measurements. The model contains a database of NTS pipeline
diameters and lengths, updated as required to accommodate changes
to the network.

The NTS is divided into pipeline sections, and the volume of gas
within each section is determined by multiplication of the pipe
free volume by the ratio of the gas density at actual conditions
to the gas density at standard temperature and pressure.

The actual gas density is computed from a standard equation of
state applying pressure, temperature and specific gravity data.
The pressure is derived from telemetered measurements at the
beginning and end of the pipeline section, and an average network
gas temperature is applied. The specific gravity is determined
from telemetered measurements at NTS entry and exit points
according to a fixed mapping arrangement. The network model then
summates the calculated volume of gas for each pipeline section
to compute total NTS linepack.

The opening NTS linepack for a gas day, which is equivalent to
the closing NTS linepack for the preceding gas day, will be the
volume calculated by the network model as close to the start of
the gas day as possible."

From this page
https://www.nationalgridgas.com/data-and-operations/transmission-operational-data

you can reach
http://mip-prod-web.azurewebsites.net/PrevailingViewGraph/ViewReport?prevailingViewGraph=ActualLinepackGraph &gasDate=2019-03-15

which is a graph showing the pressure variations.

Why did we used to need gasometers? Surely a high pressure pipeline isn't something really technologically advanced?