Temporary Outside Tap

[Nickfromwales]

Whack that lot together and see what the flow rate is actually giving you . If you've got a good water main then it may be surprisingly good. 

[ProDave]

You have obviously got somewhere to turn the water off. Can you follow it back to the stopcock and see what fitting that has and see if you can attach a larger pipe at the stopcock?

[Russdl]

@Nickfromwales I'll be doing that in the morning, so ?

 

@ProDave 

26 minutes ago, ProDave said:

and see if you can attach a larger pipe at the stopcock?

 

Probably not. The water is turned off at the meter which is on a road about 50m from the property. I found the main in the corner of our plot and a straight line from that hole to the meter would be under the 2 neighbours back gardens (green line in the image below). I suspect they wouldn't want me digging up their gardens (but I haven't asked the question yet. To replace the main, I suspect the only viable option would be to route it up the gravel track (red dotted line below). 

 

I'm hoping Nick will be right and the flow from my piddly little main will be sufficient.

 

[Nickfromwales]

A cheeky little accumulator may also save you a lot of digging. Can you get a static reading for pressure? Buy a cheap gauge and fit a non return valve on it. Leave it for 48 hrs to see what the pressure makers out at. The NRV will capture the reading so you dont have to monitor it. The best cold mains pressure is available at night, so a daytime reading is of little use when surveying to weigh up your options.   

[Russdl]

@Nickfromwales I woke up thinking about an accumulator!! I think need to arrange for some more interesting dreams ?

 

I presume the blue connector that I need to use, with the 7mm internal diameter, will have no effect on the static pressure? I also presume it will have an effect on the flow?

[Nickfromwales]

4 hours ago, Russdl said:

@Nickfromwales I woke up thinking about an accumulator!! I think need to arrange for some more interesting dreams ?

 

I presume the blue connector that I need to use, with the 7mm internal diameter, will have no effect on the static pressure? I also presume it will have an effect on the flow?

Yes, Yes, and yes. 

 

[Nickfromwales]

Oh, and PMSL

[Russdl]

Well, I have a standpipe.

 

My first dabble with blue MDPE and plasson fittings -  a bit like massive Lego, I feel like a builder, and I will now stride around in my Dunlop Safety trousers with a new feeling of self worth.

 

Being generous my standpipe is producing 15 litres of water a minute - but most importantly, it's not leaking! Now for the pressure test, I'll call the water company first...

[Nickfromwales]

15 L is borderline TBH. ?  

Lets see what pressure you've got. Hopefully north of 2 bar. ?

[Russdl]

Splendid chap from Wessex Water popped round on his way past and I've got 4 bar of pressure ? ...  but it looks like my 'stopwatch and bucket' measearument was correct - I only have 15 litres per minute flow ?

 

Is that going to be enough for potentially 3 showers running at once? If not, will I need to replace the main or will an accumulator pick up the slack?

 

[Nickfromwales]

1 hour ago, Russdl said:

Splendid chap from Wessex Water popped round on his way past and I've got 4 bar of pressure ? ...  but it looks like my 'stopwatch and bucket' measearument was correct - I only have 15 litres per minute flow ?

 

Is that going to be enough for potentially 3 showers running at once? If not, will I need to replace the main or will an accumulator pick up the slack?

 

You've got more chance of seeing two Christ's, both on bikes ?

 

Even with a new cold mains you may still struggle to run more than 2. You'd best survey off a neighbours outside tap, one nearest the street, to see exactly how you'd benefit before digging ( and parting with 4 figures )   

Do you have outbuilding space for a decent sized ( 500L ) accumulator? That would be where my money would be spent as a house with an acc is above and beyond one without. 1800mm h x 600mm w tank size iirc @ 500 litres. 

[Russdl]

@Nickfromwales I'll look into the accumulator option I think Nick. Thanks for the pointers.

[Nickfromwales]

34 minutes ago, Russdl said:

@Nickfromwales I'll look into the accumulator option I think Nick. Thanks for the pointers.

Best if you can keep it outside so you get cold water that's still cold. . 

[Jeremy Harris]

+1

 

We have two 300 litre accumulators (used two because they fitted in a narrow space more easily) and they are in a narrow shed on the North wall of the house, so they stay reasonably cool. 

 

Bear in mind that the usable volume of water in an accumulator is very roughly half the stated volume, so a 300 litre accumulator really holds around 150 litres of water, the rest is the pressurised air the other side of the bladder.

[Russdl]

@Nickfromwales Thanks for that obvious point Nick. Sadly I wasn't bright enough to think of that myself!

 

@JSHarris Thanks for that info Jeremy, how does that work, having 2? Are they plumbed in parallel? Also, what are the rough dimensions of your accumulators? 

 

I'm still head scratching about where to put it (them) if I go down that route. 

[Jeremy Harris]

42 minutes ago, Russdl said:

 

@JSHarris Thanks for that info Jeremy, how does that work, having 2? Are they plumbed in parallel? Also, what are the rough dimensions of your accumulators? 

 

 

The accumulators only have a single connection on the bottom, so normally have a tee on so that incoming water comes in one side and outgoing goes out the other side, with the accumulator connection coming off the top of the tee.  For mains pressure boosting you fit a non-return valve (NRV) on the incoming side, so that the peak pressure gets stored in the accumulator.  When connecting two (or more) together, you just run the "outlet" from one to the "inlet" to the next and they effectively work in parallel.  The dimensions vary a bit, but the 300 litre ones I have are 630mm in diameter and 1400mm high.  IIRC, they were around £300 each.  The 500 litre one would have been fine for me, but was too big in diameter to fit in the shed I'd already built.  IIRC the 500 litre one was close to being 800mm in diameter, and I only had around 700mm of room to spare inside the shed.

[Nickfromwales]

Go to PumpsUkLtd and select 'accessories'. 

Go to expansion vessels ( blue = potable ) and see the prices and the dimensions ( download PDF ). 

?

[Jeremy Harris]

Worth also contacting Dambat in Poland.  They make some pretty cost-effective tanks of good quality and with ready availability of spares: http://www.dambat.com/diaphragm-tanks.html

 

We've had one of their dirt-cheap borehole pumps in use for three years now (it was intended as a very cheap (less than £100)temporary replacement whilst we were waiting for a new Grundfos to arrive),  If the Dambat/IBO pump failed now it would still have been reasonable value.  Add in that I could probably fix it for the cost of a new impeller for £30, and their stuff starts to look like pretty good value.

[Russdl]

@Nickfromwales & @JSHarris thanks for those links. Chunky monkeys aren't they.

 

So if I were to go down this route I'd have the main going to one or two accumulators and then onwards into the house. Is the distance from the accumulator to the house important? I could probably site it (or them) in the garden some 25m from where I'd be expecting the water to enter the house.

 

 

 

[Jeremy Harris]

As long as you use reasonably large bore pipe from the accumulator to the house then they will work fine.  As you have such a small bore main, there is an advantage in getting them as far down that (in terms of distance from the house) as possible.  Either 25mm or 32mm MDPE will be fine for the run from the accumulator to the house.

[Russdl]

@JSHarris ?

 

A plan is starting to take shape. Clearly I'd need to protect the accumulator from long spells of freezing weather but I reckon I could make a shed for it at the end of the garden and then run the larger bore MDPE to the house.

[Jeremy Harris]

1 hour ago, Russdl said:

@JSHarris ?

 

A plan is starting to take shape. Clearly I'd need to protect the accumulator from long spells of freezing weather but I reckon I could make a shed for it at the end of the garden and then run the larger bore MDPE to the house.

 

 

Sounds a very good option to me.  In practice the accumulator will rarely get very cold, as when the house is occupied there will be a regular flow of water at around 8 deg C (normal mains water temp in most areas of the UK).  The case you need to protect for is having a long cold spell whilst away on holiday and not using any water.  I insulated the inside of our treatment plant shed, where the accumulators are, with 50mm of insulation, then added a 60 W tubular heater under the accumulators that is switched by a frost stat, so only comes on if the temperature inside the shed drops below 4 deg C.  I don't think it's ever come on, as it takes a fair time for such a large volume of water to cool down.

[Russdl]

10 minutes ago, JSHarris said:

then added a 60 W tubular heater under the accumulators that is switched by a frost stat, so only comes on if the temperature inside the shed drops below 4 deg C

 

That sounds like a nice simple solution. No stone left unturned.

[Nickfromwales]

2 hours ago, Russdl said:

That sounds like a nice simple solution. No stone left unturned.

To fortify your water supply with accumulators wont just solve the pressure & flow problem, but will, as a bi-product, also give you an exceptionally good water supply to the house  

You will need to plan the pipework well in advance and get the correct sizes of pipework from A>B>C plus the power for the tubular heater etc. The softener ( if required ) will need to go before the accumulators, but you can arrange the pipework accordingly and have the softener in the dwelling for ease of service if preferred. Personally I'd leave it outside with the accumulators so it can regenerate with as little annoyance as possible.  

 

[Russdl]

40 minutes ago, Nickfromwales said:

an exceptionally good water supply to the house

 

Sorry Nick, what do you actually mean by that?

 

41 minutes ago, Nickfromwales said:

get the correct sizes of pipework from A>B>C

 

I'll definitely need help there...

 

42 minutes ago, Nickfromwales said:

The softener ( if required ) will need to go before the accumulators

 

How come? It will be required.

 

If I need to go softener first, then accumulator, and this is all at the end of the garden I guess I'd need to run a separate, non softened supply to the house as well for drinking water?