Somewhat off topic regarding outside sprinkler pressure.

[Bogart]

Having got fed up moving the sprinkler around to try to cover the lawns I decided to push out the boat and get a large all singing and dancing job that looks the part. Problem is water pressure, or more aptly lack off. So I decided to fit a booster pump. I measure the water rate at around 20 litres a minute through 15mm copper and the usual outdoor tap arrangement. With the booster pump there is an increase in visible spray distance on the sprinkler but not what I was expecting. I am thinking I just need a larger pump is it that simple? This is the one currently fitted.
https://www.amazon.co.uk/gp/product/B00L90478Q/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
This is quoted as Qmax of 30 litres/min
Now I am the first to admit that pumps do confuse me re max flow rates, minimum heads etc. Do I just buy one with a bigger Qmax and all will be solved. Something like this
https://www.amazon.co.uk/BuoQua-Sta...7655&sr=1-2-spons&keywords=booster+pump&psc=1
which has a Qmax of around 85litres/min

 

[ShaunCorbs]

Can't boost from the mains

So you will have to install a tank to feed the outside tap or feed one from a water butt

 

[sammathias]

What size pipe you got feeding the system...off a hose pipe isit?

 

[Bogart]

What size pipe you got feeding the system...off a hose pipe isit?

It starts as 32 mm at the meter then somewhere on its way to the house there is a 25mm tee off that feeds an outbuilding at which on the point of entry goes down to 15mm for about 3m at the end of which is the tap.

 

[Bogart]

Can't boost from the mains

So you will have to install a tank to feed the outside tap or feed one from a water butt

Well that buggars me up then. If as you say you cannot boost the mains why is it I notice an increase, small though it may be, when the pump is running?

And just taken this off the Salamander site

"
The Home Boost Pump will...

• Boost low water pressure,
• Boost low mains water pressure and flow,
• Increase water pressure "

Which I find confusing so I gave them a call. They were very helpful in telling me that one is not supposed to take more than 12 litres/min from the mains, never knew that. So how does this work as I yesterday measured without the pump I could get around 20 litres/min?

 

[ShaunCorbs]

Well that buggars me up then. If as you say you cannot boost the mains why is it I notice an increase, small though it may be, when the pump is running?

And just taken this off the Salamander site

"
The Home Boost Pump will...

• Boost low water pressure,
• Boost low mains water pressure and flow,
• Increase water pressure "

Which I find confusing so I gave them a call. They were in telling me that one is not supposed to take more than 12 litres/min from the mains, never knew that. So how does this work as I yesterday measured without the pump I could get around 20 litres/min?

Because you could rob someone else's flow

 

[Bogart]

Also just read on the OFWAT site that water companies are supposed to maintain a pressure in their mains of 7m head. All well and good but who can ever check that? Might have to go down the route of what I first considered, but thought would be expensive, which relatively it will be. That is as I have a well at the front of the property, with a submersible pump try and use that at the rear after laying more pipework. Yet another job becomes pain.

 

[Bogart]

Finally one more question. Years since I did any physics so here goes. Taken off WRAS site

"A supply capable of delivering 9 litres/minute at a pressure of 10m head at the boundary of the property is an Ofwat reporting criterion."

Now do I interpret this as meaning if I stood at the boundary of my property up a 10m ladder I should be able to get 9 litres/min? And if I stand lower down the ladder proportionally more than 9litre/min?

 

[ShaunCorbs]

No your guaranteed a min flow and pressure of 9lpm and 1 bar

 

[Gasmk1]

as an aside to this could united utilities ( thats who supply my water) be reducing the pressure at peak garden watering times eg:- 6 till 9 i only ask as my sprinkler or hose pipe pressure during this hot weather is grossly reduced. under normal conditions the sprinkler will spray about 12 foot side to side but during this time period lucky to get 4 foot either side.

 

[Supermeteor]

Having got fed up moving the sprinkler around to try to cover the lawns I decided to push out the boat and get a large all singing and dancing job that looks the part. Problem is water pressure, or more aptly lack off. So I decided to fit a booster pump. I measure the water rate at around 20 litres a minute through 15mm copper and the usual outdoor tap arrangement. With the booster pump there is an increase in visible spray distance on the sprinkler but not what I was expecting. I am thinking I just need a larger pump is it that simple? This is the one currently fitted.
https://www.amazon.co.uk/gp/product/B00L90478Q/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
This is quoted as Qmax of 30 litres/min
Now I am the first to admit that pumps do confuse me re max flow rates, minimum heads etc. Do I just buy one with a bigger Qmax and all will be solved. Something like this
https://www.amazon.co.uk/BuoQua-Sta...7655&sr=1-2-spons&keywords=booster+pump&psc=1
which has a Qmax of around 85litres/min

 

[Supermeteor]

Hi, You're stating your water pressure's low, yet provide no numbers. Buy a water pressure gauge from Screwfix (£15), use it on your outdoor bibcock, and your washing machine tap indoors, and you'll have a number/s for (static) pressure/s. At my house, in a valley, I have 7 bar static pressure, which delivers 20/22 litres per minute to my house via a 20 mm Alkathene. At my previous home, (30 + years ago), which was a Victorian terrace, I guess I had around 4 bar static pressure (being about ten metres below the bottom of the 40 metre water tower, and allowing a percentage for pressure losses in the pipe), but we only had around 8/9 litres per minute flow rate, sometimes less, and a very low dynamic pressure and flow rate at times of high demand, due to the whole terrace of about 12 houses and three shops being supplied from a single 1/2" or 3/4" galvanized iron pipe which no-one was prepared to pay to have replaced, it crossing all the properties under the path to the rear.
I don't think your reported flow rate is unreasonable. What rate, out of interest, were you expecting or hoping for? 20 litres per minute is 1.2 cubic metres per hour, or about £6+ worth per hour where I live, including the sewage charges which are paid in proportion to, and in addition to, the water charge.
If your sprinkler's not projecting the available water far enough, (due to the dynamic pressure being low with all those sprinkler orifices...) perhaps a soaker hose might be more appropriate than the high tech electrically powered methods? Then you'd lay it in the vicinity of the parts needing irrigation, rather than projecting the water from a central point. (and, if you have neighbours, you'd not be irrigating their gardens...)
I set my father in law up with a length of JG Speedfit drilled with 1mm holes at 40mm intervals to irrigate his beans, but of course, we weren't covering such a large area, and I don't spend unnecessarily...

 

[Bogart]

No your guaranteed a min flow and pressure of 9lpm and 1 bar

Which are the OFWAT figures.

 

[Bogart]

Hi, You're stating your water pressure's low, yet provide no numbers. Buy a water pressure gauge from Screwfix (£15), use it on your outdoor bibcock, and your washing machine tap indoors, and you'll have a number/s for (static) pressure/s. At my house, in a valley, I have 7 bar static pressure, which delivers 20/22 litres per minute to my house via a 20 mm Alkathene. At my previous home, (30 + years ago), which was a Victorian terrace, I guess I had around 4 bar static pressure (being about ten metres below the bottom of the 40 metre water tower, and allowing a percentage for pressure losses in the pipe), but we only had around 8/9 litres per minute flow rate, sometimes less, and a very low dynamic pressure and flow rate at times of high demand, due to the whole terrace of about 12 houses and three shops being supplied from a single 1/2" or 3/4" galvanized iron pipe which no-one was prepared to pay to have replaced, it crossing all the properties under the path to the rear.
I don't think your reported flow rate is unreasonable. What rate, out of interest, were you expecting or hoping for? 20 litres per minute is 1.2 cubic metres per hour, or about £6+ worth per hour where I live, including the sewage charges which are paid in proportion to, and in addition to, the water charge.
If your sprinkler's not projecting the available water far enough, (due to the dynamic pressure being low with all those sprinkler orifices...) perhaps a soaker hose might be more appropriate than the high tech electrically powered methods? Then you'd lay it in the vicinity of the parts needing irrigation, rather than projecting the water from a central point. (and, if you have neighbours, you'd not be irrigating their gardens...)
I set my father in law up with a length of JG Speedfit drilled with 1mm holes at 40mm intervals to irrigate his beans, but of course, we weren't covering such a large area, and I don't spend unnecessarily...

I have got a pressure guage somewhere knocking about , which I used to pressure test some cast iron rads before installing, so will look it out. Regards the soaking hose may well do that as an alternative though they are really designed for beds and not lawns.

 

[Supermeteor]

I have got a pressure guage somewhere knocking about , which I used to pressure test some cast iron rads before installing, so will look it out. Regards the soaking hose may well do that as an alternative though they are really designed for beds and not lawns.

I mentioned the soaker hose, since my now dead, but when living, very selfish, neighbour used to use a sprinkler on his lawn and vegetable patch, treating all around him to a shower, albeit a light one. Prior to my makeshift Speedfit irrigator, my father in law had to move his sprinkler around to water his beans, and that was on a relatively small area. Now they receive their water directly. You may have noticed in films that American gardens, where they have sprinklers, they have multiple sprinklers, as do golf courses. Field irrigation uses multiple sprinklers, too, sometimes traversing fields to achieve total coverage. Remember even with a soaker, if your lawn's inclined, you'll have to supply it at the highest point, or the pressure losses in the perforations will prevent water getting to the high point...
The pressure gauge will only give you a static reading, indicating a potential to deliver. Restrictions up or downstream will limit the actual delivery. 20 litres/min is quite reasonable to my mind. The £6+ per hour would put me off (but perhaps I'd pay it rather than go to the bother my wife does to save the planet)... One day, she'll trip carrying her precious "saved" water, and the carpet replacement cost will outweigh the value of the saved water...

 

[Bogart]

Am getting 1.8 bar at this moment which is much more than I actually reckoned. We are fed from a trio of interconnected water towers the nearest being 100m away. Will ask the water people if they know if we are fed directly or the whole setup is pumped would be interesting to know. So I suppose 20 litres/minute is not too bad. Will look into piping the well water around to the back as it is free!

 

[rpm]

I`ve seen 6bar static reduce to 0.6bar dynamic pressure before.
Seems you want more pressure than flow to reach further.

 

[Bogart]

I`ve seen 6bar static reduce to 0.6bar dynamic pressure before.
Seems you want more pressure than flow to reach further.

Yes with the water flowing the pressure ie dynamic drops to buggar all nearly. Does not help that the pipework starts at 32mm then down to 25mm then to 15mm.

 

[johnduffell]

High static but low dynamic (with low flow) means a restriction somewhere on the pipework upstream of you and possibly including your neighbours.

 

[johnduffell]

@rpm interesting that you "disagree" with what's just a matter of physics - if there's a high static pressure the flow would be excellent over an unrestricted path.

but if you open the tap and hardly anything comes out and the pressure drops off a cliff, that means something like an almost closed stop tap or some muck blocking it, or a very long narrow pipe, which must be upstream because if it was downstream the pressure would remain high.

 

[rpm]

I hear you John however explain this example.
Customer buys a pump which needs 1.7bar dynamic to operate, they have 6bar static in the room but the pump will not operate.
I disconnect the pump from the supply in the room and add a dynamic flow tester and see 0.6bar.

 

[johnduffell]

I hear you John however explain this example.
Customer buys a pump which needs 1.7bar dynamic to operate, they have 6bar static in the room but the pump will not operate.
I disconnect the pump from the supply in the room and add a dynamic flow tester and see 0.6bar.

Upstream supply has too great a head loss at that flow rate, ie too high resistance