Having a natural pool at the bottom of my garden I would like to pump
water up about 12 meters over a distance of 60 metres and then use it to
water the garden. I have Googled until my head spins, also contacted
local suppliers, the information is contradictory. What is the
relationship between lift in metres and pressure? What lift or pressure
would I need at the top to operate a spray? Are larger bore pipes
preferable to smaller bore? Should I use a submersible pump capable of
handling dirty water, or non submersible with a filter on the end of the
pipe in the water? I have tried emailing companies that "offer advice"
by email, however no reply after a week. Is there anyone here who can
help or point me to a source of information please?

Broadback wrote:
Having a natural pool at the bottom of my garden I would like to pump
water up about 12 meters over a distance of 60 metres and then use it
to water the garden. I have Googled until my head spins, also
contacted local suppliers, the information is contradictory. What is
the relationship between lift in metres and pressure? What lift or
pressure would I need at the top to operate a spray? Are larger bore
pipes preferable to smaller bore? Should I use a submersible pump
capable of handling dirty water, or non submersible with a filter on
the end of the pipe in the water? I have tried emailing companies
that "offer advice" by email, however no reply after a week. Is there
anyone here who can help or point me to a source of information
please?

E-mail me off group - I have a contact who could probably help.


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On Mon, 30 Apr 2007 19:06:24 +0100, Broadback wrote:

What is the relationship between lift in metres and pressure?

AIUI "lift" is how far a pump can suck water up from below itself. The
absolute limit is around 32' or 10m as "lift" is due to the atmosphere
pushing down on the water and forcing it up the pipe due to the partial
vacuum being formed by the pump. Above 32' a hard vacuum will form, think
of a mercury barometer.

What lift or pressure would I need at the top to operate a spray?

2 or 3 bar minimum I should think, pressure is more related to flow rate
and pump power than anything else.

I'd go a for a pump that can shift the water the distance required up into
a storage tank and then water the garden from that. The pump down the
bottom of the hill operated from a float switch in the storage tank (and
in series with one at the pump so that it doesn't try to pump nothing.

BTW I don't think this gets you out of any hosepipe ban. They ban
hosepipes full stop, it doesn't matter what the source of water is. You
may also need to have a licence to abstract any water from the pool.

--
Cheers
Dave. pam is missing e-mail

On Mon, 30 Apr 2007 19:06:24 +0100, Broadback wrote:

Having a natural pool at the bottom of my garden I would like to pump
water up about 12 meters over a distance of 60 metres and then use it to
water the garden. I have Googled until my head spins, also contacted
local suppliers, the information is contradictory. What is the
relationship between lift in metres and pressure? What lift or pressure
would I need at the top to operate a spray? Are larger bore pipes
preferable to smaller bore? Should I use a submersible pump capable of
handling dirty water, or non submersible with a filter on the end of the
pipe in the water? I have tried emailing companies that "offer advice"
by email, however no reply after a week. Is there anyone here who can
help or point me to a source of information please?

--
Cheers
Dave. pam is missing e-mail

In an earlier contribution to this discussion,
Broadback wrote:

Having a natural pool at the bottom of my garden I would like to pump
water up about 12 meters over a distance of 60 metres and then use it
to water the garden. I have Googled until my head spins, also
contacted local suppliers, the information is contradictory. What is
the relationship between lift in metres and pressure? What lift or
pressure would I need at the top to operate a spray? Are larger bore
pipes preferable to smaller bore? Should I use a submersible pump
capable of handling dirty water, or non submersible with a filter on
the end of the pipe in the water? I have tried emailing companies
that "offer advice" by email, however no reply after a week. Is there
anyone here who can help or point me to a source of information
please?

Pumps suitable for this sort of application can produce high pressure at low
flow or high flow at low pressure - or something in between. [If you plot
pressure against flow, you get a boomerang-shaped graph, which is concave
upwards, and you need to study the graphs of any candidate pumps].

In round figures, you need a pressure of 1.2 bar to lift water by 12 metres.
So if you had a pump which could produce 1.2 bar at zero flow, water would
just trickle out of the top of the pipe - which wouldn't be a lot of use. So
you need to decide what flow rate you want, and a find a pump which can
produce an adequate[1] pressure at that flow rate.

I'm not sure that it matters whether the pump is submersible or not. In any
event, you need to ensure that the intake is suspended above the bottom of
the pool so that you don't suck up a lot of mud.

[1] What does adequate mean? You need 1.2 bar for the lift plus (say) 1 bar
to overcome the flow resistance of the pipe (big pipe is better than small)
and perhaps another 1 bar to generate some force at the spray nozzle. So 4
bar at your chosen flow rate should be more than enough.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On Mon, 30 Apr 2007 19:06:24 +0100, Broadback wrote:

Having a natural pool at the bottom of my garden I would like to pump
water up about 12 meters over a distance of 60 metres and then use it to
water the garden. I have Googled until my head spins, also contacted
local suppliers, the information is contradictory. What is the
relationship between lift in metres and pressure? What lift or pressure
would I need at the top to operate a spray? Are larger bore pipes
preferable to smaller bore? Should I use a submersible pump capable of
handling dirty water, or non submersible with a filter on the end of the
pipe in the water? I have tried emailing companies that "offer advice"
by email, however no reply after a week. Is there anyone here who can
help or point me to a source of information please?

Some options a
a submersible pump
- dirty water ones are more expensive and if your pond is full of weed
and wildlife it'll get choked on the weed and do mayhem to the wildlife.
- you could put a clean water one in a large mesh basket to strain the
water think of a plastic laundry basket the size of a large bucket or
small dustbin lined with something like geotextile material. Since the
flow is through a large surface area it shouldn't be so easy to get
clogged and the tadpoles and fish won't get mangled


non-submersible pump:
- diaphragm pumps can suck water up but don't shift much volume and are
expensive
- central heating pumps can shift a good flow and head (similar to
submersibles) and can often be obtained for free (from skips or
friendly plumbers) but the pipe on the inlet side must be full of water
and airtight before it'll shift anything, so you need to prime it before
using it

With either you'll want a basket-type strainer on the inlet.


Given the head and distance you'e dealing with I'd be inclined to couple a
cheap clean-water submersible in a strainer basket with a skip-grade CH
pump to boost the flow up your 12m head.

In any case get well genned-up on outside electrics! RCDs, waterproof
connectors & switching, a waterproof enclosure for the CH pump etc.