Pump Requirements

[Katsuren]

Residential building is 350m (1,200') from city water source (clean potable water only)
Elevation change is an increase of 30m (100')
Flow Rate: 10-15 GPM
Power source = Electric
Pipe: 2.5 cm (1") black poly pipe
Climate: Tropical: HI = 28.4 °C | 83.1 °F, LOW: 15.6 °C | 60.1 °F
Tank above building: 4 ton 1,056 GL) switched tank to turn off pump when full

Questions:
How many pumps would I need?
What is best type of pump to use in this case?
At two points, there are straight up 4m gains. Does that change requirements?

 

[Artisi]

Is the 30m head inclusive of the elevated tank?


It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Katsuren]

Darn! I though I thought of everything.
Thank you for asking. 30m + 5m to top of tank

Head = 35m

 

[Artisi]

Just quickly without running any calcs. Think the 1" poly pipe is way undersized.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[itsmoked]

15GPM in a 1inch pipe yields about 6ft/s thru the pipe. That's acceptable. But an 1-1/4' would probably be better if the cost doesn't change greatly.

Add about 0.4ft of head per foot for cramming that water thru the 1" pipe (friction head loss).

So your head is more yet!

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LittleInch]

So depending on your flow and pipe size you probably need about 45 to 50m head at the inlet.

That's about 5 bar.

One pump will easily do this but you need to know what the flowing pressure is from the city supply to size the pump.

A simple centrifugal water pump will do this.

Note that city water suppliers are often reluctant to allow people to pump water out of their system and have rules to follow.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Artisi]

15 USgpm thru 300 metres of 1" poly pipe gives you about 48 metre head loss plus static head of 35 equals 83 or so metres total head. Achievable with 1 centrifugal pump however increasing the pipe diameter is recommended and could be a better financial solution.
Can you pump directly from the town main or will you require a "break-tank" between the main and your pump.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Katsuren]

After double checking, it appears the pipe is actually 3 cm.
This is rural Japan and the city recommends this solution so connecting is no problem.
Your responses have confirmed my suspicions. One contractor was quoting a need for 3 pumps.

Follow on questions.
1. With the 3cm pipe gain, what head loss can I expect?
2 Will two 90 degree pipe bends add even more head?
3. The GE elevation data below for area is old. The 91m point on the chart is actually closer to 100m but you get the idea.
Private property and city roads limit the pump location. It can be placed within 30m of source or within 80m of tank.
At what point along the run should the pump be placed?

 

[itsmoked]

Your new location requirements, give-or-take elevations, new pipe dimensions, and other (we can imagine) aspects are painting a wonky bunch of data Katsuren. This is also starting to add up to some serious money. You should no longer be getting advice from us because very small details can easily derail the system resulting in bad performance, early failures, or a complete failure to launch.

At this point you should engage the services of a local pumping professional and/or a local water systems engineer who will know which small details need serious consideration in your project.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Artisi]

You need to give a definite static head, not near enough- from the source to the highest delivery point.
A spec on the pipe, especially ID. is it high density or low density as pressure rating could be a problem.


It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Katsuren]

Thank you all. You've been a great.