4 millibars over 2 minutes - gas cost?

DVardysShadow

macman wrote: »

Any chance you can explain that in a bit more detail please?;)

Is this a roundabout way of saying you got stuck?

macman

DVardysShadow wrote: »

Is this a roundabout way of saying you got stuck?

No I did not get stuck!
TBH I never got started...:D

rushal

errrrr, I've spotted a mistake in your calculation :rotfl:

C_Mababejive

cattkitt wrote: »

The disastrous news is that my gas pipes are leaky, and I've been disconnected. *shiver*

The good news is that it's set me to thinking, my gas bills have been really high despite my frugality measures to reduce them.

So, does anyone know how much it was costing me if my gas pipes were leaking 4 millibars over two minutes(or whatever the time measure they use is)

Thank you for any help!

If you had never smelled gas,how did you come to be in a situation in which the system was tightness tested and the pressure loss noted?

ollski

As a very rough guide a pressure gauge would lose pressure from 20mb to 0 with a small pilot light still running on a boiler in about 3 seconds If its taking around 120 seconds for it to drop 4mb then that would equate to about 600 seconds for your leak to drop to zero. By my reckoning if an average permanent pilot light costs around 50 quid a year I reckon your leak was probably losing maybe a couple of quid a year. Wildly rough but an approximation.

DVardysShadow

ollski wrote: »

As a very rough guide a pressure gauge would lose pressure from 20mb to 0 with a small pilot light still running on a boiler in about 3 seconds If its taking around 120 seconds for it to drop 4mb then that would equate to about 600 seconds for your leak to drop to zero. By my reckoning if an average permanent pilot light costs around 50 quid a year I reckon your leak was probably losing maybe a couple of quid a year. Wildly rough but an approximation.

You must scale by the relative volumes of your pipework and the OP's from the respective stop valves.

If your gas system is 2m of 15mm and the OP's is 20m of 22mm, that is a factor of about 20. If it is the other way about, it is another factor of 20, so overall a factor of 400 uncertainty in this answer.

DVardysShadow

rushal wrote: »

errrrr, I've spotted a mistake in your calculation :rotfl:

:eek::eek::eek:

I don't suppose you are going to help the OP by saying where it is? :rotfl::rotfl::rotfl:

brewerdave

Ah....where would this forum be without Basic Thermodynamics I:rotfl:

Cardew

ollski wrote: »

I reckon your leak was probably losing maybe a couple of quid a year.

so overall a factor of 400 uncertainty in this answer.

So the best estimate of an answer to the 'straightforward question' is between 1 penny and £400 a year - roughly!

DVardysShadow

Cardew wrote: »

So the best estimate of an answer to the 'straightforward question' is between 1 penny and £400 a year - roughly!

Who knows? Perhaps rushal will be along to spot a mistake in a minute.