Huge pressure difference in different areas of the property

[Agile]

Back to an earlier question!

When you turn off the single stopcock what does the pressure gauge do ?

If the pipes are not leaking then the pressure in each pipe will remain on the 1.1 or 2.9 respectively! Do they ???

Tony




PS

What are the relative heights of the outside taps above ordnance datum?

 

[arranjj]

I wish I tried that earlier! That will be my first job in the morning. The stopcock is on an A road and requires cones and daylight.

I see where you're going with this (underground leak nearer the low pressure pipe), and makes sense. It's just a leak that significant is something I'm sure I would have noticed. I first did these pressure tests about 6 months ago, so we're talking about 5 million litres at least! I must check my bill!

 

[arranjj]

The lower pressure tap is actually slightly lower (!) than the higher pressure one, but there is nothing in it really - both about 100m above sea level

 

[Agile]

You have not answered the question about a water meter.

If you had one it twould be wizzing round for a leak.

If you dont have a meter then the water bill is on the old rateable value bases.

Tony



PS heights of properties above ordnance datum?

 

[arranjj]

100m approx - both roughly the same. I do have a meter, but I am quite a high user, so whizzing is about right. The meter is in a manhole on an A road - a bit inconvenient to say the least! I will attempt a late-night recon mission after midnight with a car spotter. I have my manhole keys at the ready!

 

[Agile]

Can you not turn off ALL water taps and uses inside the properties and just see if the meter continues to turn?

Presumably you are not feeding lots of field troughs on which some are the constantly overflowing type?

Tony

 

[arranjj]

Yes that is exactly what I will do when I can safely get in the road to do so. Certainly there shouldn't be any usage at all with all the taps off.

 

[arranjj]

Just to update - it seems you were right! The meter is reading 20 litres per minute with nothing on!

Have spent the whole day digging and it seems we're getting close (large amount of water), so it's only a matter of time before we find the leak. It seems obvious now, but many thanks for the advice.

 

[arranjj]

And now fixed! One of the 25mm underground pipes had split. Pressure now reads 4 bar everywhere!

View media item 20888
Many thanks again!

 

[rojaca]

Nice leak. Nice to get there in the end.

Tony. Right at the start of this you suggested there may be a leak which from the pressure difference you estimated to be in the range of 10-20l/min. What calculation did you use for this?

 

[matt1e]

An underground leak ???

That would indicate a very significant leak! Perhaps 10-20 litres/per minute.

Tony

Just to update - it seems you were right! The meter is reading 20 litres per minute with nothing on!

And now fixed! One of the 25mm underground pipes had split. Pressure now reads 4 bar everywhere!Many thanks again

View media item 20888

Nice leak. Nice to get there in the end.

Tony. Right at the start of this you suggested there may be a leak which from the pressure difference you estimated to be in the range of 10-20l/min. What calculation did you use for this?

I'm quite impressed too agile................clever sh'te!!