How do they regulate mains water pressure?

[Ron Lowe]

I was just looking at mains water pressures recently. I've seen it vary from 3 to 7 bar in our area. Seems typical enough.

That got me wondering. How do they regulate the pressure?

If we lived in flat-land, then they could regulate at the reservoir or pumping station. But we don't live in flat-land.

The hydrostatic head of 10m head of water is roughly 1 bar, so I can't see how one regulator could satisfy a hilly area without the top of the hill and bottom of the hill having too wide a pressure difference. 40m of elevation would be the difference between 3 bar at the top of the hill and 7 bar at the bottom. Anything more than 40m elevation difference would require seperate regulation, to my mind.

Do they have regulators dotted up and down the streets?

Where are they? Burried underground?

[Ron Lowe]

I was just looking at mains water pressures recently. I've seen it vary from 3 to 7 bar in our area. Seems typical enough.

That got me wondering. How do they regulate the pressure?

If we lived in flat-land, then they could regulate at the reservoir or pumping station. But we don't live in flat-land.

The hydrostatic head of 10m head of water is roughly 1 bar, so I can't see how one regulator could satisfy a hilly area without the top of the hill and bottom of the hill having too wide a pressure difference. 40m of elevation would be the difference between 3 bar at the top of the hill and 7 bar at the bottom. Anything more than 40m elevation difference would require seperate regulation, to my mind.

Do they have regulators dotted up and down the streets?

Where are they? Burried underground?

[The Natural Philosopher]

I always assumed they didn't.

That is the 5 bar we see here is the average height of the water tower above my kitchen tap...its about 10 meters high and on land 40 meters higher than we are..

[Gordon Henderson]

Our water pressure is ~8bar. Comes from way up the hill behind us. A leak here is quite "interesting"!!!

Gordon

[Roger]

The message from The Natural Philosopher contains these words:

But you live in flatland where 100 feet is a big hill. :-) The highest point in Suffolk is only 419 feet AMSL.

Here in Yorkshire 500 feet is not an uncommon difference in height between the top and bottom of an urban road. I live about halfway up such a hill. I don't know the actual pressure (at a guess above 3 bar) but it is quite high and before they replaced the water main and reduced the pressure considerably it was horrendeously high. They must have some means of regulating pressure.

[The Natural Philosopher]

Hedaer tanks and ball valves halfway up the hill ?

:-) :-)

[Roger]

The message from The Natural Philosopher contains these words:

I really don't know how they do it but one way would be to have in-line pressure reducers at regular heights. If 3 - 7 bar was an acceptable range then they would be needed every 120 feet of altitude change.

[Mike Barnes]

Are you sure you're not exaggerating?

[manatbandq]

He isn't. .

Where I lived there was a small resevoir at 705'. The bottom of the valley, down the road, was 246'. Whether it's all supplied from the same resevoir at the top of the hill is another matter.

MBQ

[Dave Fawthrop]

|In uk.d-i-y, Roger wrote: |>Here in Yorkshire 500 feet is not an uncommon difference in height |>between the top and bottom of an urban road. | |Are you sure you're not exaggerating?

Manchester Rd, Bradford is about 500ft from Bradford to Odsal. That is the first one I thought of. There are several urban roads which change names several times during the climb.

[Tony Williams]

This village has a reservoir at the top of the hill. The main piping works in both direction though, down during the day, and water pumped up to the reservoir overnight. There used to be massive pressure surges overnight, ballcocks lifting, and a short life for all valves. That is, until the water authority also began to regularly blow their own ancient 4" asbestos mains. Rather than replace the mains they first of all started to tanker water to the reservoir, then installed a separate feed pipe from the other direction.

[AJH]

3 valleys water are just fitting a pressure reducing valve by me, this is so they can complete a ring main around the town and feed a large housing estate by either leg of the main. Chief reason is that the currently used leg is very corroded and needs replacing.

AJH

[Mike Barnes]

And that's an urban road, is it? Not disagreeing, just surprised. I won't stoop to pointing out that it's less than 500 feet. :-)

In any event, the number of such roads as a proportion of urban roads must be very small. So I'd say "uncommon" was actually pretty accurate.

[manatbandq]

Weeell, it depends how you define urban. There's more than one way down to the valley bottom, most are built up and it's less than two miles form the centre of Huddersfield.

Just visit any West Yorkshire mill town where the major population centres were originally up the hill but were overtaken by valley bottom development around the new fangled water mills. Now they're largely one urban sprawl, although the residents may claim otherwise ;-). Almost

*all* of the urban road go uphillI. I would say "not uncommon" was an accurate description in this context.

MBQ

[Dave Fawthrop]

|In uk.d-i-y, wrote: |>

|>Mike Barnes wrote: |>> In uk.d-i-y, Roger wrote: |>> >Here in Yorkshire 500 feet is not an uncommon difference in height |>> >between the top and bottom of an urban road. |>>

|>> Are you sure you're not exaggerating? |>

|>He isn't. . |>

|>Where I lived there was a small resevoir at 705'. The bottom of the |>valley, down the road, was 246'. Whether it's all supplied from the |>same resevoir at the top of the hill is another matter. | |And that's an urban road, is it? Not disagreeing, just surprised. I |won't stoop to pointing out that it's less than 500 feet. :-) | |In any event, the number of such roads as a proportion of urban roads |must be very small. So I'd say "uncommon" was actually pretty accurate.

In the West Riding of Yorkshire quite common. maybe Darn Sarf they are uncommon. Bradford to Queensbury A647 urban all the way. Well over 500ft

[Roger]

The message from Mike Barnes contains these words:

Not for this area of Yorkshire. 400 feet between valley bottom and the edge of urban habitation might be more typical but 500 feet was quoted as it is the height difference on my hillside. Greater height differences can be found. Queensbury, a suburb of Bradford, and little more than 4 miles from the city centre is a good 800 feet higher.

[Roger]

The message from Mike Barnes contains these words:

That would depend on whether you are thinking of road names or road lengths but for the avoidance of doubt as to what I actually ment just substitute 'area' for 'road' in my original statement.

[Mike Barnes]

At the risk of flogging a dead horse: that looks to me like several roads (Chester Street then Morley Street then Easby Road then Dirkhill Road then turn right onto All Saints Road then turn left into Great Horton Road then Highgate Road then Scarlett Heights then Sand Beds then High Street (E&OE)). And some of them, especially at the upper end, border far too many fields to fit with my idea of "urban" roads.

Stepping back a bit, I'd never claim there weren't any. But it still seems to me that they're far from commonplace, even in Yorkshire, and people seem to have to stretch definitions in order to identify one.

[Mike Barnes]

More exaggeration, I suspect. Is it something in the Yorkshire air? The AA route planner makes the distance 4.9 miles and Google Earth gives the height difference as 711 feet.

[Dave Fawthrop]

|In uk.d-i-y, Dave Fawthrop wrote: |>On Wed, 13 Sep 2006 15:14:32 +0100, Mike Barnes |>wrote: |>

|>|In uk.d-i-y, wrote: |>|>

|>|>Mike Barnes wrote: |>|>> In uk.d-i-y, Roger wrote: |>|>> >Here in Yorkshire 500 feet is not an uncommon difference in height |>|>> >between the top and bottom of an urban road. |>|>>

|>|>> Are you sure you're not exaggerating? |>|>

|>|>He isn't. . |>|>

|>|>Where I lived there was a small resevoir at 705'. The bottom of the |>|>valley, down the road, was 246'. Whether it's all supplied from the |>|>same resevoir at the top of the hill is another matter. |>| |>|And that's an urban road, is it? Not disagreeing, just surprised. I |>|won't stoop to pointing out that it's less than 500 feet. :-) |>| |>|In any event, the number of such roads as a proportion of urban roads |>|must be very small. So I'd say "uncommon" was actually pretty accurate. |>

|>In the West Riding of Yorkshire quite common. maybe Darn Sarf they are |>uncommon. Bradford to Queensbury A647 urban all the way. Well over 500ft | |At the risk of flogging a dead horse: that looks to me like several |roads (Chester Street then Morley Street then Easby Road then Dirkhill |Road then turn right onto All Saints Road then turn left into Great |Horton Road then Highgate Road then Scarlett Heights then Sand Beds then |High Street (E&OE)). And some of them, especially at the upper end, |border far too many fields to fit with my idea of "urban" roads. | |Stepping back a bit, I'd never claim there weren't any. But it still |seems to me that they're far from commonplace, even in Yorkshire, and |people seem to have to stretch definitions in order to identify one.

Like I said the A647.