Electric Water Pump Sizes vs Distance - What / Which / When etc

Right,

I am asking as I have genuinely run out of brain power @ moment. Trying to look after 2 moody cats, 2 howling puppies, a wife and house build has totally discharged my neural network.

Water Pumps -

I need to bring water from the river to the 1st stage holding tank through a sand filter sediment tank. Distance approx 20 meters rising to 4 meters for the top of the first tank. - So what should I be looking for ?

1st to 2nd tank via 2nd filtering system, 2nd tank direct to another pump for distribution length of up to 100meters around the garden and house. ( everything on the ground floor, but might need it for on the 2nd floor sprinkler system )

I have been looking everywhere at pumps and all I am seeing is on average 8mts suction / 20 - 30 mts distribution. My bemused brain is telling me it does not equate there and as I am not a fluids engineer I am frankly a little out of comfort zone.

We already have a couple of mitsubishi 200watt (i think) constant pressure ones but after 20meters transmission I have seen a rabbit pee further, so not impressed at all with performance. Ideally something that is a basic automatic one, turn on tap it kicks in, float in tank drops, it kicks in, that it.

Any sage advice, ideas or wisedom would be greatly appreciated at this time......



(As, after carefully drawing up all the plans for the tank installation and explaining and having the wife translate, I came back home this afternoon to discover they had welded up the tank stands arse about tit, asking why, as it was graphically drawn with 1 tank on the top and 1 on the bottom, I was told oh .. we thought 2 on top and no problem water still go from bottom of tank 1 to top of tank 2 it work same same. The roaring lecture on basic pressure principles was utterly lost, but it was therapeutic for 10mins until the F in L chimed in with the word SILICONE ... that initiated meltdown mode and I stalked off before the silicone tube went somewhere else.)

Welcome Zim, out of interest what is this water for, your house mains? and why you chose to pump from a river rather than a borehole?

Cheers Dude,

Basically, house is on a tributary of the Kwai, looked at getting a borehole put in, both for the house and the resort, but as usual and after a lot of we pay, you pay.. no you pay, we pay back I have got the hell in with family politics and have gone for the self sufficient option as a 150k to drop is a little steep.

So water is basically silty, not bothered about bacteria etc as water is boiled, so its mainly to provide a clean source for washing machine, shower, sprinkler system etc. I have spent more on new t shirts and clothes in the last 6 months than in the last 6 years ... everything is a varying shade of brown or grey :sssh:

Duplicate answer as it didnt post straight away, sorry

Is this even posting .. ignore, it posted

Not sure where you are located I am in Nahkan Sawan on the banks of the Ping river river we have 15 rai of fruit trees and pump from the river to irrigate the orchard and the garden around the house. Having said that I would not recommend pumping from the river to many problems flooding in the rainy season and low water in the dry season. We have lost many meters of pipe we put in when the river would go down being swept away when the river came up over night. You will constantly be cleaning your intake foot valve much to do to keep it working. I also would recommend you get some one to drill a well if possible a deep well below the clay layer as your water will be much cleaner.We have city ware for our house water and we still use 2 filters(a fa Rick filter and a media filter just to clean up the water for showering then a 3 stage filter for drinking. Hope this helps.

Quote:

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Originally Posted by Zimbabwean

Right,

Water Pumps -

I need to bring water from the river to the 1st stage holding tank through a sand filter sediment tank. Distance approx 20 meters rising to 4 meters for the top of the first tank. - So what should I be looking for ?

1st to 2nd tank via 2nd filtering system, 2nd tank direct to another pump for distribution length of up to 100meters around the garden and house. ( everything on the ground floor, but might need it for on the 2nd floor sprinkler system )

I have been looking everywhere at pumps and all I am seeing is on average 8mts suction / 20 - 30 mts distribution. My bemused brain is telling me it does not equate there and as I am not a fluids engineer I am frankly a little out of comfort zone.

We already have a couple of mitsubishi 200watt (i think) constant pressure ones but after 20meters transmission I have seen a rabbit pee further, so not impressed at all with performance. Ideally something that is a basic automatic one, turn on tap it kicks in, float in tank drops, it kicks in, that it.

Any sage advice, ideas or wisedom would be greatly appreciated at this time......

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Firstly you need to learn to read a pump curve chart, that will tell you what size pump you need to achieve the duty you want.
Just use Google and there are sites that explain it all i.e. how to read them.

Next you need to determine the "real" head" this includes the vertical lift, but there are also friction losses for every fitting and lengths of different types of pipe. For example using a right angle bend introduces the need for more energy than a 45 degree bend. In line valves add friction losses i.e. increase head required. Your in line filters will increase head required also.

You say you have a 200W pump which in my mind s what you would use in a fish tank. If it is instead a 2000W pump it is still only 2.7HP which is still a small pump

When you run your pipes use the largest diameter you can as it will dramatically alter the volume of water out the end. Most of my water distribution pipes are 1inch PVC and then I usually choke it back at the tap outlet by using a half inch riser to the tap.

As for using mechanical float valves I would avoid them as they can cause your pump to cycle on/off too much or too often. Instead spend the money and get electrical mercury switches which you can then set at the levels you want i.e. Off switch 50cm from top of tank and On switch at half empty that way your pump comes on and pumps a half a tank full each time.

If you are still going to persist with pumping water from the river you need to take precautions as stated by RPETER65, and these should include a floating pontoon to allow the pump to rise and fall with the water level in the river. A coarse filter under and around your pumps intake area to prevent it from being blocked which would require cleaning and then make sure your pontoon is very firming anchored to something that is not going to get washed away in a flood i.e. a couple of 2 tonne concrete blocks buried in the ground.

If it were me I would also think about separating the water for the garden from the water for the house maybe this is as simple as putting a take off in the line between your first and second filters. Your garden water does not need (in my opinion) to be as filtered as your house water.

Last piece of advice is after you have done your calculations of the head your pump will be seeing add a safety factor of at least 25% i.e. if you determine you need a 6HP pump get a 7.5HP pump.

Your head will hurt a lot more before you finish, good luck!

All very valid points and some excellent input from you, so thank you. Will be referring back to this on a regular basis.


My borehole days were back in Africa 30 years ago, but then it was 30hp electric motors and pumping stations on the farm, and it is knowledge that my old man had in bundles, sadly I never quite paid enough attention to the finer points.

Floating Poonton is certainly on the books as the tributary is tidal and I have seen the perils of rapidly rising and falling here already. Hence the houseboats are cabled to large mature trees.

The garden supply I can switch over to a separate flow pipe, a little redesign and cutting will sort that one out.

The 90 bends and curves I have kept to a minimum and the supply pipes again, 2" cutting down to 1" for the house.

Throwing out another idea here just as a sounding board, possibly 2 smaller pumps after the tanks, (one halfway over the distance) might sound overkill, but just an idea.


But yes, Brain Numbness will be setting in rapidly and please accept advanced apologies for weird ideas, thoughts and lots of mumbling.

Your help is appreciated

I got this one for my house, works good. 5,800 baht

Product details MITSUBISHI Automatic Water Pump (Round Tank) Model WP-255R Size 250W (Yellow)

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  • 250 watt water pump, suction distance 8 meters (vertical), delivery distance 22 meters (vertical)

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  • 1 inch inlet pipe
  
  
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  • Suitable for 2-3 storey houses
  
  
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  • high power motor Strong water power, durable
  
  
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  • The pressure vessel is coated with a special paint. Both inside and outside, anti-rust, non-toxic.
  
  
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  • The pump head is made of copper alloy, making it durable and does not rust. Torque.
  
  
• 
  
  • Add a ground wire for the safety of installing the machine when in use.
  
  
• 
  
  • high energy saving with energy-saving label 5

ปั๊มน้ำอัตโนมัติ MITSUBISHI (ถังกลม) รุ่น WP-255R ขนาด 250W (สีเหลือง) | Lazada.co.th

Somewhat untechnical, but will give you an indication.


Attachment 77135Attachment 77136

Zim

The first pump doesn't need to be particularly large as it can if necessary run while you are asleep. 8 metres suction lift is quite normal for common water pumps. Most are 9m.
Discharge, you only need 4metres plus friction loss for 20 metres which is not much. If worried you can always come out of the pump at one size and expand the 20m pipe up one size say from 1 inch to 1 1/2.

My brain is also hurting at present but there are lots of website for friction loss in small bore pipes.

http://mitsubishielectricmalaysia.co...pump-specs.jpghttp://mitsubishielectricmalaysia.co...pump-specs.jpghttp://mitsubishielectricmalaysia.co...pump-specs.jpg

You state lift and distance required but not required discharge capacity/volume.

As illustrated in the chart above, from vocalneal, column 5.

A calculation of your daily requirements and storage capacity is essential.

Quote:

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Originally Posted by Zimbabwean

Throwing out another idea here just as a sounding board, possibly 2 smaller pumps after the tanks, (one halfway over the distance) might sound overkill, but just an idea.

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This idea of having 2 pumps in line and in series is not a good idea, if the first pump fails then the second will end up sucking air and most likely burn out, if the second pump fails then the first just keeps pumping and unless it has a pressure switch to turn itself off then it will likely overheat and fail. So in summary a recipe for disaster unless you create a staged pumping system which means the first pumps to a holding tank that the second draws water from the they are independent of each other and only depend on the inlet water being available.

As VocalNeal says your pump/s don't need to be large but you need to determine that they can meet the demand you place on them.
That is the first pump pumping to a tank has 24 hours to fill it with enough water to cover what you use in the whole day.
The second pump will have varying demands placed on it when you water the garden, have a shower etc. but it will not be sustained all day.

As for your first pump i.e. the one going into the river I would be inclined to go for a submersible pump probably more expensive but no need to worry about the electrics getting wet. Fix it to a float and tethered with a steel cable.
The second just use a pump similar to what Vocal Neal showed as something like that would do the job.

We have a couple of Lucky Star pumps on 2 of our wells (bores) 1 lifts from 6m the other from 35m. In our third well we have a submersible which lifts from 65m.
The submersible delivers 60L per minute the other (the 6m well is not used) delivers 6-8L a minute.

The submersible pumps to 6 BCM's (6000L) and then this is distributed for watering the gardens using a Mitsubishi on demand pump. When we used this water to irrigate we hooked a Honda pump to the BCM's and it delivered 200L per minute. So 2 hours to fill the BCM's 30 minutes to empty them. The submersible is controlled using 2 mercury switches located in 1 of the BCM's which are all linked so they balance out the water level.

Finally I don't really think you need to go to 2inch PVC unless you want to deliver 200L a minute like we did. If you go from 1 inch to 1&1/4 you increase the volume by 50%.


P.S. Just seen OhOh's post and as he and I said calculate your supply and demand numbers and use storage to balance them where you can.

How high is the second tank? is the pump at ground level? what is the flow rate of the pump? What type, length and diameter pipe are you using? how many bends? That would help for starters. You may find this useful if you have the right information.

Pressure Drop Online-Calculator