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CaptainSplod

Connect Water Pump Directly To Mains Pipe?

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Hi Folks!

We have a problem with low pressure water coming from the mains. That's to say the

pressure is mostly ok during the day, but in the evenings the pressure is way too low.

I can imagine it's quite a "popular" problem in many parts of the country, along with

powerouts, internet connections and all the other things. We live in a very small

village out in the burbs.

I'm thinking of buying a small water pump to maintain a steady flow, but being a

complete novice (read: idiot!) at this sort of thing, I'm hoping that you more

intelligent and experienced guys can help out with some good advice. :D

Really, it all boils down to just wanting to take the evening shower. We don't

need a whole bunch of fancy installations and gadgets all over the place, but

just want to keep things as simple as possible. We're talking about using a pump

for around 15 minutes a day, that's all.

Checked with the Thai neighbor - they don't have a water pump but use

something they call (in Thai) a "dye naam", which I gather is a 'dynamo',

though what it looks like and how it operates is anybody's guess, as the

neighbor only makes use of the contraption. It was apparently already there

when he bought the land some years back. Maybe some of you guys know

what this thing is.

Here's some info on what we have :

Half inch standard Thai water pipe coming in from the mains, to the

one-storey house, which also has half inch pipes.

The pipes are all visible i.e on the ground and on the outside house-walls - none

under the house - and no hidden or buried pipes.

No water tank - and would preferably not want to have one, either.

One bathroom with toilet, bum-hose, sink and shower (with water heater).

One outside tap.

Later, we're planning on adding another (likewise) bathroom and

one more outside tap - which all in all ain't a great deal. We don't

actually use a whole lot of water, either, and try to save where

possible. Yeah, I'm 'green' in more ways than one! :)

To me, the "normal" setup is to have a tank connected to the mains,

then have a water pump installed between the tank and the house.

BUT -

1. Can I attach a pump directly to the mains, without having any problem?

2. Seeing as this is mostly an "evening" problem, I don't really

need to to have the pump turned on during the day - and certainly

not during the night - but will I still get the normal mains water

pressure in the house, with the pump turned off or in a powerout?

3. Any recommendations as what brand/type of pump I should

use - and cost? Seem to remember that standard size for inlet

and outlet pipes on a pump is one inch - is that so?

4. Just out of interest, do pumps have a "reverse" switch, so

that water can be pumped the other way?

5. Anything I should avoid or be careful of?

Sure hoping you guys can help out - and thanks for your time!

PS 'Scuse me putting this post here, ain't sure where it ought

to go - thanks. :D

Splod

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Have a look in D.I.Y

Go to the bottom of the page and key word pumps, a whole range of topics appear, there might be something helpful there.

Edited by Mossfinn

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In most countries it is illegal to pump from the mains, that said it is common practice here.

The issue is that without check valves you could pump crud from someone elses bath / pond into the main and thence to your taps. Better to install a holding tank filled from normal mains pressure and pump from that.

Moving this to DIY.

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I agree with Crossby that you should install a holding tank before the pump. However, in order to achieve a good flow of water you need not only consider the pressure but also the flow and your half inch pipes are indeed a limiting factor. These thin pipes will limit the amount of water that you can pump into your house irrespectively of the pressure, but since your requirement is moderate I do not see that it will matter in your case.

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I agree with Crossby that you should install a holding tank before the pump. However, in order to achieve a good flow of water you need not only consider the pressure but also the flow and your half inch pipes are indeed a limiting factor. These thin pipes will limit the amount of water that you can pump into your house irrespectively of the pressure, but since your requirement is moderate I do not see that it will matter in your case.

Basicly you are competing with your neighbors to get water. The lowest positioned tank gets most of the water.

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Install the tank. It should be as stated between the mains supply and the house. Pump only from the tank when mains supply is low or off. The pipes and valves should be connected in such a way as to provide water from the mains when the supply is good and when the supply pressure is low the pump will automatically give you water from the tank. No need to switch on the pump manually. Also check valves are places to prevent any back flow to the mains supply and tank.

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Please use a tank - I do not see anyone pumping direct anymore here in Bangkok but not sure if that is for legal reasons or not - but it is a danger to you and others if you start to bring septic water into the mains leaks by having them go negative pressure.

I would just use the pump as it gives the chlorine in water a chance to breath out and makes for better taste. Also less plumbing. But would include a tank/pump bypass option in even pump fails/tank needs cleaning and such. Another advantage of tank is you will have water during short outages.

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Your pump setup should look something like this:-

post-14979-1257402587_thumb.jpg

The non-return valve ensures that the city supply provides water when its pressure is high enough that the pump is not needed, it also ensures a water supply when the power is off or the pump out of service.

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Just managed to read the first coupla replies before having to work

the rest of the day.

Look in the DIY link - thanks - I'll see what I can turn up!

Ain't a good idea to connect directly to the mains. Yeah, get your

point, though will have to look up "check valve" to see what that

little puppy does.

Appreciate for the info so far - and will get back to other replies :)

Splod

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A 'check valve' is UK plumber speak for a non-return valve.

Unfortunately nothing you do will prevent the possibility of drawing ground water into the main through one of the (doubtless many) leaks.

Get the tank, you know it makes sense :)

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That is a new one on me. Wiki lists four terms as below - must admit have never heard it called "clack valve" either - your backflow preventer at least makes sense in my American English.

A check valve, clack valve, non-return valve or one-way valve is a mechanical device, a valve, which normally allows fluid (liquid or gas) to flow through it in only one direction.

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Use a tank,

1) You don't suck the water from the entire community for yourself.

2) Sucking water from the main will make your water meter spin like crazy. The inertia of the meter sometimes spins more than the water you actually use.

3) You will maintain a steady supply of water to your pump.

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My use of the term "back flow preventer" comes from my MS Visio with a small rectangle diagram and "BFP" in the center of the box. The shape is described as a backflow preventer . Don't know what Google or Wiki says

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Whoa! - seems to be an awful lot of equipment is needed for just

a few minutes good supply of water! But really appreciate all your

comments!

Yep - the pressure falls a whole deal in the evening, reckon the locals

return home from work and wash, make food, fill up their water tanks(?)

and hence the decrease in pressure. Looks like most places have the

half inch pipes (from what we can see) - we ain't planning on getting a

bathtub, jacuzzi or anything fancy and the water system otherwise works

reasonably well (at least for the moment!).

This is a pretty small and 'simple' area with many people using open

concrete water tanks to store their household water - outside bathrooms and

that sorta thing. Ain't really nothing modern anywhere, no ponds in people's

gardens, no drains, no bathtubs (I'm guessing) or modern septic tanks and all

grey waste water usually goes directly out to the kitchen garden, 'cept for the

toilet, which is connected to a sunken concrete ring tank. The main point

here is that you get water piped to your land, but there are no return pipes

or drainage of any sort - all water is "in", none "out". Getting someone else's

crud is maybe nigh impossible, save perhaps with a broken mains pipe.

Hey, Crossy - thanks for the neat diagram, too - very informative.

Anybody know what the "dye naam" thing is?

Lastly - any takes on questions 3 and 4?

Thanks, guys

Splod

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